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Transparent Ready User Guide

1. Number of Requests Server Response Time CPU Cycles Needed To Complete 47 20 ms 4 cycles 50 ms 8 cycles 70 ms 10 cycles 100 ms 12 cycles 60 20 ms 5 cycles 50 ms 10 cycles 70 ms 14 cycles 100 ms 18 cycles 40 35 4 ye 20 4 AZ Lae 25 4 3 9 20 4 100 ms coms 6 F 50 ms 5 as T s Are ae 10 4 rv Ce a A 20 ms d li 10 ms 20 ms lt 1 ms 0 t T T t T t t t t t 0 5 10 15 20 25 30 35 40 45 50 55 60 Communications Completed A sampling of results in the chart follows Number of Requests Server Response Time CPU Cycles Needed To Complete T 22 lt 1 50 ms 2 cycles 70 100 ms 3 cycles 3 50 ms 3 cycles 100 ms 4 cycles 7 10 20 ms 3 cycles 50 ms 4 cycles 70 100 ms 5 cycles 8 100 ms 6 cycles 31006929 8 2007 409 Modbus Client Performance Number of Requests Server Response Time CPU Cycles Needed To Complete 15 10 ms 4 cycles 20 70 ms 5 cycles 26 50 70 ms 6 cycles 100 ms 7 cycles 31 70 ms 8 cycles 100 ms 11 cycles 37 50 ms 9 cycles 70 ms 13 cycles 100 ms 16 cycles 39 lt 1 ms 4 cycles 100 ms 17 cycles 50 10 20 ms 6 cycles 50 ms 13 cycles 70 ms 20 cycles 100 ms 26 cycles 60 lt 1 ms 5 cycles 10 ms 7 cycles 20 ms 8 cycles 50 ms 18 c
2. Device MIB II TFprivate MIB 170ENT11001 X X Device Configuration Web Files Security 170ENT11001 X X xX Device Configuration Diagnostics Security 171CCC96020 X X 171CCC96030 X X 171CCC98020 X X 171CCC98030 X X 170ENT11001 X X X 31006929 8 2007 253 Services Overview Other Services Supported by Advantys STB Devices SNMP Device SNMP v1 SNMP v2 SNMP v3 MIB II TFprivate MIB STBNIP2212 x X Xx FTP Device Configuration Web Files Security STBNIP2212 xX Xx xX Other Services Supported by Power Logic Gateways Bridges SNMP Device SNMP v1 SNMP v2 SNMP v3 MIB II TFprivate MIB EGX 200 x X EGX 400 xX X FTP Device Configuration Web Files Security EGX 200 X xX EGX 400 X xX X 254 31006929 8 2007 Services Overview Other Services Supported by ConneXium Cabling Systems SNMP Device SNMP v1 SNMP v2 SNMP v3 MIB II TFprivate MIB 499NES17100 X X xX 499NOS17100 X X X 174CEV30020 X X 174CEV20030 X X 174CEV20040 X X FTP Device Configuration Web Files Security 174CEV20040 X X X TFTP Device Configuration FDR Support 499NES17
3. EE o o SD Site distributor PD Plant distributor POD Plant office distributor FW Firewall PFD Plant floor distributor CD Cabinet distributor DO Device outlet FD Field distributor ONoOahWHND Industrial Site An industrial site distributor plays the same role as a campus distributor in the ISO Distributor IEC 11801 standard as the distributor from which the backbone cable emanates This distributor is managed by IT personnel and can be one or more devices racked switches with multiple numbers of ports Typically it is located in an office environment and provides the connection for the entire manufacturing site to the Internet and to other physical sites in the same company or organization Traffic in and out of the site is isolated by a router see p 65 and secured by a firewall 31006929 8 2007 41 Planning and Layout Industrial Site Backbone Plant Distributor Office Plant Distributor and Plant Floor Distributor Cabinet Field and Machine Distributors The industrial site backbone is the cabling system that extends from the industrial site distributor to the plant distributors Typically the industrial site is a self healing ring see p 51 that can be made redundant with a dual self healing ring see p 53 The plant distributor connects the industrial site backbone to a plant It acts as a building d
4. Home Statistics Bootp Server Data Editor Graphic Editor Alarms Viewer FactoryCast Schneider Automation Inc 1998 2000 i 23 Internet A Ethernet statistics Ethernet statistics include IP parameters the number of packets transmitted and received and any errors at the Ethernet layer Device properties Device properties display the current product version the operating system and the firmware or kernel version Menu Menus display lists of pages available from a device Device configuration The device configuration shows the service configurations on the device Device diagnostics Device diagnostics are the diagnostics of the services on that device 228 31006929 8 2007 Services Overview Devices that Support Standard Web Server Services Product Reference Quantum Processor 140CPU65150 140CPU65160 Modules 140NOE771001 140NOE 77111 140NWM10000 Premium Processor TSXP572623M TSXP572823M TSXP573623M TSXP574823M TSXP571634M TSXP572634M TSXP573634M TSXP574634M TSXP575634M Module TSXETZ4103 TSXETY110WS TSXETY5103 TSXWMY 100 TSX Micro Modules TSXETZ410 TSXETZ510 Momentum M1E processors 171CCC96020 171CCC96030 171 CCC 980 20 171 CCC 980 30 Modules 170 ENT 110 01 17
5. Number of Requests Server Response Time CPU Cycles Needed To Complete 1 lt 1 10 ms 2 cycles 20 ms 4 cycles 50 ms 5 cycles 70 ms 3 cycles 100 ms 5 cycles 10 ms 3 cycles lt 1 ms 3 cycles 70 ms 4 cycles 100 ms 6 cycles 11 lt 1 ms 4 cycles 10 ms 5 cycles 20 ms 6 cycles 50 ms 15 cycles 70 ms 12 cycles 100 ms 22 cycles 418 31006929 8 2007 Modbus Client Performance Number of Requests Server Response Time CPU Cycles Needed To Complete 18 lt 1 ms 5 cycles 10 ms 6 cycles 20 ms 13 cycles 50 ms 16 cycles 70 ms 22 cycles 100 ms 28 cycles 22 lt 1 ms 6 cycles 10 ms 7 cycles 20 ms 18 cycles 50 ms 27 cycles 70 ms 35 cycles 100 ms 50 cycles 39 lt 1 ms 9 cycles 10 ms 12 cycles 20 ms 33 cycles 50 ms 81 cycles 70 ms 109 cycles 100 ms 159 cycles 48 lt 1 ms 10 cycles 20 ms 16 cycles 20 ms 64 cycles 50 ms 159 cycles 70 ms 220 cycles 100 ms 314 cycles 31006929 8 2007 419 Modbus Client Performance Modbus Client Response Times Quantum 140 CPU65150 with an Embedded Ethernet Port Test Setup The following charts show Quantum PLC response times where the client request block is triggered in PLC logic by reading data from a Modbus server The graphs represent the number of CPU cycles required for the PLC to complete all triggered Modbus client requests In all cas
6. 1 4 lt 1 100 ms 2 cycles 5 100 ms 3 cycles 9 50 ms 3 cycles 14 70 ms 3 cycles 20 100 ms 4 cycles 23 20 ms 3 cycles 70 ms 4 cycles 100 ms 5 cycles 28 50 ms 4 cycles 70 ms 5 cycles 100 ms 6 cycles 36 10 ms 3 cycles 20 ms 4 cycles 50 ms 5 cycles 70 ms 7 cycles 100 ms 9 cycles 43 20 ms 5 cycles 50 ms 7 cycles 70 ms 9 cycles 100 ms 13 cycles 48 50 ms 10 cycles 70 ms 13 cycles 100 ms 18 cycles 414 31006929 8 2007 Modbus Client Performa nce at a CPU Scan Time of 100 ms 25 4 CPU Cycles Communications Completed A sampling of results in the chart follows Number of Requests Server Response Time CPU Cycles Needed To Complete 1 lt 1 50 ms 2 cycles 70 100 ms 3 cycles 2 4 lt 1 100 ms 2 cycles 100 ms 3 cycles 50 70 ms 3 cycles 15 20 50 ms 3 cycles 70 ms 3 cycles 100 ms 5 cycles 18 20 ms 4 cycles 50 ms 3 cycles 70 ms 4 cycles 24 50 ms 5 cycles 70 ms 3 cycles 100 ms 5 cycles 31006929 8 2007 415 Modbus Client Performance at a CPU Scan Time of 50 ms Number of Requests Server Response Time CPU Cycles Needed To Complete 32 10 ms 3 cycles 20 ms 5 cycles 50 ms 8 cycles
7. At a Glance Overview This chapter introduces you to Transparent Ready a major strategic program to deploy Internet technologies in Schneider Electric products and services What s in this This chapter contains the following topics Chapter Topic Page Transparent Ready 16 Transparent Ready Service Classes Offered 19 Users of this Guide 23 How this Guide Is Organized 24 31006929 8 2007 15 Transparent Ready Transparent Ready What Is Transparent Ready What Are Internet Technologies What Is Industrial Ethernet In 1996 Schneider Electric proposed a combination of technologies that transformed industrial automation This approach employed a combination of the physical and data link layers of Ethernet as defined by the OSI model see p 124 with TCP IP and Modbus for industrial Ethernet solutions The concept originally known as Transparent Factory has evolved to become the Transparent Ready initiative Transparent Ready is a major strategic initiative that deploys Internet technologies into Schneider Electric s products and services Any Schneider Electric product or service that supports Internet technologies is a Transparent Ready product Internet technologies describes a set of technological innovations that allow information to be managed through the Internet and related hardware software languages and protocols They are used to transfer present and
8. above Number of Devices to Scan Time from Scanned Device Input to Scanned Device Output ms 140CPU65150 v2 0 10 ms 20 ms 50 ms 100 ms 200 ms Embedded Ethernet Port Scan Scan Scan Scan Scan v3 1 1 device 25 46 112 220 409 8 devices 26 47 113 222 412 16 devices 28 49 115 223 423 32 devices 42 62 129 241 443 31006929 8 2007 389 I O Scanner Performance 140CPU65150 The 140CPU65150 used for the following measurements is at version 2 0 and the with 140NOE771x1 Ethernet communications module is at version 3 5 140NOE771x1 Module 700 600 500 400 300 Time ms 200 100 4 a 0 bs i T T T T 50 100 150 200 PLC Scan Time ms The curves above show that response times remain within 5 to 7 ms of each other whether 1 8 16 or 32 devices are used The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Scanned Device Output ms 140CPU65150 v2 0 10 ms 20 ms 50 ms 100 ms 200 ms NOE771x1 v3 5 Scan Scan Scan Scan Scan 1 device 35 61 153 302 602 8 devices 36 62 154 303 603 16 devices 38 64 155 305 606 32 devices 40 66 157 307 609 390 31006929 8 2007 I O Scanner Performance 140CPU43412A The 140CPU43412A used for the following measurements is at version 2 0 and the with an 140NOE
9. Plant B 31006929 8 2007 63 Planning and Layout Virtual Circuits Dial up Services Virtual circuits are logical circuits created within a shared network There aretwo kinds e switched virtual circuits SVCs which are dynamically established on demand and terminated when transmission is complete e permanent virtual circuits PVCs a more expensive option for situations where data transfer between devices is constant Dial up services for a WAN can be an economical solution when your enterprise does not generate a lot of transmission traffic Dial up is also frequently used as a backup for other WAN technologies Network managers can perform remote troubleshooting on a modem connected over an inexpensive dial up line to a router if the main link is down 64 31006929 8 2007 Planning and Layout WAN Hardware Summary Routers WAN Switches Access Servers Modems In order to connect from your network to other networks some devices are needed routers WAN switches access servers modems CSU DSUs ISDN terminal adapters A router is a logical switch that joins your network to the WAN and to connect from the WAN to your other network location There is a router at each end of the WAN Some routers may have the physical connection inside but sometimes the physical connection device is external Switches have layer 3 capabilities which combine the advan
10. 116 31006929 8 2007 Planning and Layout Example 2 Below is an example of terminal equipment in a work area connected to a host server using three permanent links two optical fiber links and a balanced cable link D BD FD 4 E ay terminal equipment host optical fiber cable optional opto electronic converter balanced cable channel ahoOnND The optical fiber and balanced cable links are connected together using an optical fiber to balanced cable converter a cross connect and two equipment cables There are interfaces to the cabling at each end of the permanent link Interfaces to the cabling are specified at the terminal outlet and at any point where application specific equipment is connected to the cabling The work area and equipment cables are not included in the permanent link 31006929 8 2007 117 Planning and Layout Channels Introduction Example 1 A channel is a collection of permanent links formed by passive sections of cable connecting hardware work area cords equipment cords and patch cords Channels do not cross switches or hubs which are considered end points in any channel You should test all permanent links individually and then test the channels The diagram below shows an example of terminal equipment in a work area connected to a host server using two channels an optical fiber channel and a balanced cabling channel CD BD FD
11. If there is a loss of communication with one or more remote devices the I O scanner applies configured fallback values to the corresponding I O scanner memory areas If a communication failure occurs the I O scanner does not control remote device operation These devices handle their own fallback states Enable disable allows you to start and stop the data exchange between a remote device and the I O scanner device Four double word registers are designated to the 128 entries in the I O scanner configuration Each I O scanner entry is controlled by a single bit When a control bit is turned on the data exchange is disabled and the health bit is turned off after the time out period expires At this point the TCP socket to the remote device is closed This feature can be used to limit the number of concurrent sockets to a remote device For example in a Modbus Ethernet to serial bridge which supports a limited number of concurrent TCP sockets turning on the control bit that was turned off opens a new socket and enables the I O scanning exchange to resume However the health bit remains off until the first data exchange with the remote device is completed successfully 172 31006929 8 2007 Services Overview Health Bit Operation Diagnostic Word Support TCP Socket Usage The health bit indicates whether or not a data exchange has been successful If a fault occurs but is resolved within the health time out
12. 5 Apply a coating of paint or grease on nuts and bolts at each contact point to protect against corrosion Maintain the connection over time Connection e Paint locking compounds and Teflon tape act as insulating materials and prevent Notes clean contact between metal surfaces at connection points If a cabinet or metal surface including the bottom plate has been painted remove the paint before making a connection After the connection is made you may paint the connection materials to prevent corrosion e Make sure all exposed metal components and units that are fitted in a cabinet are bolted directly onto the earth plane plate 31006929 8 2007 503 Earthing Grounding Procedures Making a Because Ethernet operates at frequencies higher than 10 MHz you must ground Connection cable shielding at both ends to obtain maximum EMC effectiveness If your site does Between Cable not have equipotential bonding you can make a connection to one end only and still Shielding and provide acceptable but not as effective operation Follow these steps to create a Metal Surfaces quality connection between a cable shielding and a metal surface Step Action Comments 1 Select the appropriate cable for a Schneider Electric strongly recommends that you use STP cable at Transparent Ready installation least CATS for any Transparent Ready installation Schneider Electric also recommends that you us
13. terminal equipment host optical fiber cable optional opto electronic converter balanced cable channel aaron The optical fiber and balanced cabling channels are connected together using an optical fiber to balanced cable converter There are four channel interfaces one at each end of the copper channel and one at each end of the optical fiber channel Equipment connections are not considered to be part of the channel All work area cords equipment cables and patch cords are included in the channel 118 31006929 8 2007 Planning and Layout Example 2 The diagram below shows a cable channel that connects a workstation to telecommunications closets TC Channels unlike links include the connecting hardware equipment cords work area cords and patch cords The cable channel runs from the patch cord 1 at the workstation to the patch cord 8 inside an extended closet It connects the work area to the closets over a horizontal subsystem that includes two cables and a transition point TP 1 patch cord patch panel 3a horizontal cable b horizontal cable transition point patch panel patch cord patch panel patch cord 3a 3b 90 m max 1 6 8 10 max 31006929 8 2007 119 Planning and Layout Testing a Copper Installation Introduction Example Testers Comparison of Testers
14. e The user is already aware of the firewall e The user examines the packets with an Ethernet packet capture tool to verify proper transmission of the socket open request but a socket is not established because no response is received Topic Issue Cannot log in to the device or cannot perform the desired action An incorrect username or password is usually the cause of this problem The user interface can detect this problem and display an error message In the absence of a user interface the problem can be hard to distinguish from the previous error above Cannot perform the desired function This problem is common when the current username does not provide access to the desired action for example an attempt to write a file is made with a read only login The user interface can detect this problem and display an error message In the absence of a user interface the problem can be hard to distinguish from the previous error above 31006929 8 2007 359 Troubleshooting Faulty Device Replacement BootP Troubleshooting Address Assignment These tables describe troubleshooting for faulty device replacement see p 204 and BootP see p 134 Topic Problem Solution No response from the server toa request for an IP address The server does not list the device by either rolename or MAC address This usually happens when you add a replacem
15. Low voltage mains interference voltage fluctuation brief power failures voltage dip surge voltages frequency variations waveform harmonics transients carrier currents phases unbalanced power short circuits overloads effects on voltage malfunction of connected devices such as high speed relay dropout during voltage dips loss of power potential destruction of electronic hardware The following table provides an overview of the sources of HF interference For example exchange of electrons between the body and fabric as a person walks across a carpet or of clothes worn by an operator sitting on a chair Type Sources Effects of EMI transients lightning malfunction of nearby faults to earth equipment commutation failures in inductive circuits contractor coils solenoid valves etc Electrostatic between a person and an object malfunction of nearby discharge between electrostatically charged objects equipment potential destruction of equipment The following table summarizes ways you can reduce EMI for LF versus HF disturbances Preventive Measures for LF Phenomena Preventive Measures for HF Phenomena Protective systems Filtering Appropriate cable lengths Equipotential bonding of exposed conductive parts interconnections Careful cable routing Selection of quality cables Proper connections for HF conditions Cable shielding Protective systems are mo
16. Planning and Layout Climate Protection Requirements Introduction Temperature Requirements Operating Temperature Table Storage Temperature Table Climate requirements for an industrial Ethernet include ambient temperature during operation storage temperature humidity UV exposure Temperature can affect industrial automation devices and Ethernet infrastructure components such as cables connectors and accessories in many different ways Extremes in temperature can affect performance For example extreme cold can cause cable to become stiff brittle and hard to work with whereas elevated temperature can soften or even melt the plastic used in a cable Attenuation in the standard off the shelf CAT 5E cable increases at a rate of 0 4 per degree Celsius above 20 The ambient temperature is the temperature of the environment surrounding the device Measure the ambient temperature for a device at 30 to 40 cm from the exterior surface of the device in order to allow for the effect of heat and airflow in the immediate vicinity The two tables that follow show the ambient temperature ranges for operation and storage If the ambient operating temperature is within the given range while the device is in operation that device is being used within its temperature specifications Environment Operating Range Reference Light Industrial 0 to 60 degrees C IEC 60654 1 Heavy Industrial 20 to 85 degrees C IE
17. Serial Devices with 500 ms Response Time 16000 5 14000 4 12000 4 10000 80004 3 Tay o 6000 4 i E H 4000 4 2000 4 r 1 6 i J 6 0 mae 0 20 40 60 80 100 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 500 Timeout EGX200 Time to Complete All Requests 1000 ms 1 Retry Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 2200 83 5794 163333 9900 83 2194 17 5740 836667 9794 17 187 5 16 2200 83 6114 163333 10650 83 2194 17 5915 836667 10169 17 187 5 32 2200 83 6517 496667 11450 83 2194 17 6102 50333 10569 17 187 5 64 2200 83 7264 163333 13050 83 2194 17 6475 836667 11369 17 187 5 100 2200 83 8104 163333 14850 83 2194 17 6895 83667 12269 17 187 5 456 31006929 8 2007 Gateway Performance D 2 EGX400 Gateway Serial Server Response Time and Timeout Measurements At a Glance Overview What s in this Section The performance of serial devices with response times of 50 ms 100 ms 200 ms and 500 ms are measured as they communicate across a network through an EGX400 Modbus to Ethernet gateway Network speeds of 9600 baud and 19 200 baud are considered Measurements are taken for both successful communications and
18. 306 31006929 8 2007 Services Overview Gateway with Application Protocol Conversion A gateway with protocol conversion takes a message from the source network and converts it to the appropriate destination message format and sends it to the destination network The gateway then waits for a response and converts the response before sending it back to the source network The gateway actually reads the application message from the source network but refers to an internal table to find the message to be sent onto the destination network This conversion is required when the source and destination networks do not use the same application layer protocol Gateways that use this system include those that connect Modbus networks to networks from other vendors Because the message from the source network must be received and interpreted before an outgoing message is sent this type of gateway is slower than a gateway that does not do application protocol conversion The rules for protocol conversion are based on rules defined by the gateway designer only messages identified by the designer can be converted Messages defined after the gateway is designed are not converted You cannot normally modify the mapping of messages from one network to the other This type of gateway is only able to map a simple message for which there is an equivalent on both networks Messages with no equivalent on the other network cannot be mapped As a result
19. Humidity UV Radiation Solar Radiation Liquid Pollution Gaseous Pollution 30 31006929 8 2007 Planning and Layout gt Increasing Severity gt Class Electromagnetic ESD E E E3 Radiated RF Conducted RF EFT Surge Magnetic Field ISO IEC 24702 To avoid different proprietary developments the Customer Premises Cabling Unification of working group ISO IEC JTC 1 SC 25 WG3 was created This group in turn Major Standards launched the Industrial Premises Task Group ISO IEC JTC 1 SC 25 WG3 IPTG Committees To achieve maximum cooperation and expedite the development of an international standard the Industrial Premises group has directly involved experts from the major standards organization committees IEC TC65C TIA TR42 9 and CENELEC TC215 WG1 The purpose of this new group is to standardize the characteristics of cabling systems for industrial facilities The standard will be published as ISO IEC 24702 The Industrial Premises Task Group is jointly led by ISO IEC JTC 1 SC 25 and IEC SC 65C e The JTC 1 SC 25 subcommittee is responsible for cabling for building sites e The IEC SC 65C subcommittee is responsible for cabling for process control The IEC SC 65C is a subcommittee of the IEC TC65C in charge of developing standards for industrial networks Due to the fact that the ISO IEC 24702 standard is currently being developed
20. Information technology Generic cabling systems EN 50173 and or EN 50098 1 or 2 Planning Design Phase Specification and Quality Assurance EN 50174 1 Installation planning and practices inside buildings EN 50174 2 Installation planning and practices outside buildings EN 50174 3 Testing of Installed Cabling EN 50346 Application of Equipotential Bonding and Earthing in Buildings with EN 50310 Information Technology Equipment Implementation Planning Phase Specification and Quality Assurance EN 50174 1 Installation planning and practices inside buildings EN 50174 2 Installation planning and practices outside buildings EN 50174 3 Testing of Installed Cabling EN 50346 Application of Equipotential Bonding and Earthing in Buildings with EN 50310 Information Technology Equipment Testing of Installed Cabling EN 50346 Operation Phase Specification and Quality Assurance EN 50174 Part 1 The ISO IEC 11801 2000 standard specifies cabling systems for commercial properties which may include one or more buildings on a campus The standard defines the requirements for both copper and fiber optic cables Although the standard s focus is office buildings the principles of the standard are applicable to other types of installations In general the ISO IEC 11801 standard provides performance requirements for individual cable links conformance requirements and verification procedures re
21. 140CPU65150 The 140CPU65150 used for the following measurements is at version 2 0 with an with Embedded embedded Ethernet port at version 3 1 Ethernet Port 450 400 350 4 300 4 250 4 200 4 Time ms 150 4 100 4 50 4 1 16 devices 100 PLC Scan Time ms 150 200 The lower curve shows that the response times for 1 to 16 devices remain within 2 ms of each other regardless of the PLC scan time The upper curve shows that the response times for 32 devices are 7 to 8 ms greater The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Local Output ms 140CPU65150 v2 0 10 ms 20 ms 50 ms 100 ms 200 ms Embedded Ethernet Port v3 1 Scan Scan Scan Scan Scan 1 device 22 41 102 202 402 8 devices 23 42 103 204 403 16 devices 24 43 104 204 404 32 devices 31 49 110 211 410 31006929 8 2007 393 I O Scanner Performance 140CPU65150 The 140CPU65150 used for the following measurements is at version 2 0 with a with 140NOE771x1 Ethernet communications module at version 3 5 140NOE771x1 Module 700 600 500 4 400 Time ms gt a Pa 200 4 100 0 4 T T T T 1 0 50 100 150 200 250 PLC Scan Time ms The curves above show that the response times for all devices remain are the same for 1 8 16 an
22. A terminal emulation program used to remotely control servers A concentrator that facilitates communication between hosts and terminals A special connector used on both ends of a standard Ethernet or thin wire Ethernet segment It provides the cable with 50 Q of termination resistance trivial file transfer protocol On computers that run TCP IP networking software TFTP is used to quickly send files across the network with fewer security features than FTP Half inch diameter coaxial cable Coaxial cable similar to that used for television video hookups An interrupt signal sent by a device that has not received the input it has waited a given time for 538 31006929 8 2007 Glossary token ring topology TP trace route transceiver transceiver cable Transparent Ready services A computer network in which a bit pattern called a token is passed around a circular topology or ring of computers in order to prevent collision of data between two computers trying to send messages at the same time The arrangement of the nodes and connecting hardware that comprises the network Types include ring bus star and tree twisted pair Cable consisting of two 18 to 24 AWG solid or stranded copper conductors each coated in an insulating material that are twisted together The twisting provides a measure of protection from electromagnetic and radio frequency interference TraceRT is a route tracing tool used to
23. An FDR service comprises an FDR server and a client The server is a passive device it simply stores all the parameters for the devices on the network To configure the server create a list of the devices connected to the network each identified by a rolename and their IP parameters After the FDR service is enabled the server responds to requests from the FDR clients The FDR client is a network device that stores its parameters on the FDR server to facilitate replacement of the device Each client is assigned a rolename that uniquely identifies it from other devices on the network After the device is connected to the network it sends a copy of its operating parameters to the server The actual parameters depend on the type FDR client device but they should always be sufficient to enable a replacement device to be configured to operate exactly as the original client After the server has a copy of the parameters the client periodically checks to see that the server has a current set of parameters An update is sent to the server when there is a change in the client s operating parameters Depending on the client s implementation this update may or may not be automatic If a client fails the following occurs Sequence Event 1 Your service personnel must assign the same rolename to the replacement device 2 Your service personnel places the new device on the network The device automatically issues a request to the
24. IEC 61131 2 The TIA EIA 568 A standard is one of the first cabling standards developed jointly by TIA and EIA The TIA EIA 568 A standard defined the wiring system for voice and data networks a structured hierarchical star topology network in which high speed fiber optic cables feed slower peripheral networks The standard was incorporated into TIA EIA 568 B in 2000 This table summarizes updates to the TIA EIA 568 standard Standard Description TIA EIA 568 A 1995 Wiring Standards Commercial Building Telecommunications Defines a standard for building cable systems for commercial buildings that support data networks voice and video It also defines technical and performance criteria for cabling 31006929 8 2007 487 Standards and Considerations Standard Description TIA EIA 568 A 1998 1999 Updates A1 outlines propagation delay and delay skew parameters A2 specifies miscellaneous changes A3 defines requirements for bundled and hybrid cables A4 defines NEXT and return loss requirements for patch cables A5 defines performance requirements for enhanced CAT5e TIA EIA 568 B 1 2000 Commercial Building Telecommunications Wiring Standard Incorporates previous updates into a new release and specifies Category 5e cable as preferred due to its performance Several addenda specify technical information for 100 ohm twisted
25. Sample The following example of build time runtime system supports architectures that Architecture require e frequent application modifications e a higher level of service for synchronization between the SCADA and a running application during modifications Synchronization is managed through dynamic exchanges between OFS and Unity Pro XL No manual operation is necessary to update the symbols file for OFS Unity Pro XL SCADA SCADA server STU files on Unity Pro a PC server ynchronizationjby dynamic exchange STANDBY Unity PLCs A One PC is used for the SCADA OFS and Unity Pro XL in server mode Another PC is used to run Unity Pro for application modifications and a third PC is required to achieve redundancy for Monitor Pro The PC server for the STU application files enables consistency to access from either the OFS Unity Pro XL system and the Unity Pro to the same application 270 31006929 8 2007 Services Overview Build time The architecture described above is recommended for a normal standby Runtime Options redundancy system for Monitor Pro In architectures that do not require redundancy the STU application file can be located on the PC where the OFS SCADA and the Unity Pro XL system are running Key System Characteristics Unity Pro XL is
26. Services Overview Time Synchroni zation Description Sequence of events Recording Action Synchronization Time synchronization uses SNTP to distribute the server time to all clients that implement this service The central time server may run independently or be connected to a GPS receiver a DCF receiver or a remote clock using NTP The NTP service operates in Greenwich mean time and local time zones and is administered by the clients Several time servers can operate on the network to provide redundancy in case the primary server goes out of service To maintain accurate time clients request the time from the server at configured intervals Clients may make adjustments for network delays in the time transfer Once the client receives the time an internal clock keeps track locally At the next configured update the client requests the time from the server and synchronizes its local clock The client s time accuracy is affected by the accuracy of the local clock the update period and the accuracy of the time server Many devices can be used as a time server e g a Windows or Linux PC with a 1 to 30 ms accuracy a dedicated time server with better than 1 ms accuracy The time server maintains its time by using a local clock while receiving updates from a remote source like a GPS or a DCF receiver During time synchronization all the clients request the time from the time server Each client s internal clock is syn
27. With static pages such as those from an EGX Gateway or an NOE configuration screen the client needs to a refresh the page request to update the data The Web server accesses the HTML page obtains the real time data updates the HTML file and then sends the information back to the destination The client can request updates as needed With dynamic pages such as Ethernet statistics on a NOE module the data updates are provided by Java applets The client requesting the data must have a JVM running When you access HTML files the static portion of the HTML file is downloaded along with the Java applets The Java applets running inside the JVM on the client issue a Modbus request for the device to obtain the real time data an http server a Web page request for a Web page current dynamic data values placed into the Web page device memory akrhon 226 31006929 8 2007 Services Overview Common Web The more common Web pages are Pages rack viewers data editors Ethernet statistics displays device property displays menus device configuration screens device diagnostics displays Rack Viewers A rack viewer is supported in Ethernet TCP IP modules for the following platforms and devices TSX Micro Premium Quantum Momentum Advantys STB FactoryCast gt 0o o o ee typical rack viewer Web page looks like this 4 Quantum Configured Local Rack Microsoft Internet Explorer Of xj i Fie Edt v
28. ion Section Topic Page The Global Data Service 198 Global Data Considerations 202 31006929 8 2007 197 Services Overview The Global Data Service Summary Global Data Standards The global data service on Ethernet provides the ability for one device to publish real time information to the network Any device connected to the network can choose to receive this information Devices that need to exchange information are arranged in distribution groups Each device in a group can choose to publish a block of data to the entire group and can select blocks of published data that it wants to subscribe to receive li l I The global data service is implemented using the standard network data distribution service NDDS NDDS uses the real time publish subscribe RTPS protocol as defined by Real Time Innovations RTI This has been adopted as a standard by the Object Management group OMG the same group responsible for the COBRA standard The global data service is responsible for the mechanics of distributing data over an IP network by using multicast technology s lt pm e O00 TT Coe L J00 ii P publisher S subscribers The combination of the above services distributes the global data using UDP IP multica
29. 1 Email notification sent regarding pump run hours 2 multiple site report maintenance to contractor via email 31006929 8 2007 219 Services Overview Electronic Mail Notification Service Operation Service Operation The electronic mail notification service is implemented inside an Ethernet communication module that serves as an email client When a preconfigured event or alarm is triggered in the controller the Ethernet module uses SMTP over TCP port number 25 to communicate with an email server That server is connected to the plant s network or to the Internet thereby allowing the email message to reach its recipients Email or SMS short message service messages may also be sent to mobile phones if the client s email server has the capability 5 1 he input event email triggered email sent to the mail server Internet or email system local mail server email message displayed oahwh Even though notifications are sent automatically after an event or alarm is triggered there may be a significant delay before the recipient gets the message The message is processed by an email server sent through the Internet or company mail system processed again by an email delivery server then accessed by the recipient through his her email account A notification sent to a mobile phone is received only when the phone is on and within the coverage area Therefore this service should only be used
30. 1865 333333 3558 666667 172 100 615 3333333 3718 666667 7265 333333 443 6666667 2345 333333 4518 666667 172 460 31006929 8 2007 Gateway Performance Serial Devices with 200 ms Response Time Time ms 10000 4 9000 4 8000 7000 6000 5000 4 4000 4 3000 4 2000 1000 4 20 40 60 80 Number of Registers 100 The table below shows the data points used to generate the graph represented above Device Serial Server Response Tlme 200 EGX200 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 385 3333333 1878 666667 3585 333333 378 666667 1825 3333333 3478 666667 172 16 435 3333333 2278 666667 4385 333333 403 666667 2025 3333333 3878 666667 172 32 488 6666667 2705 333333 5238 666667 430 333333 2238 6666667 4305 333333 172 64 595 3333333 3558 666667 6945 333333 483 666667 2665 3333333 5158 666667 172 100 715 3333333 4518 666667 8865 333333 543 666667 3145 3333333 6118 666667 172 31006929 8 2007 461 Gateway Performance Serial Devices with 500 ms Response Time Time ms 16000 4 14000 4 12000 4 10000 4 8000 4 6000 4 4000 4 2000 4 20 40
31. 8 Requests 16 Requests Bridge Registers Time 1 2200 83 2994 163333 3900 83 2194 17 2940 836667 3794 17 187 5 16 2200 83 3344 163333 4650 83 2194 17 3115 836667 4169 17 187 5 32 2200 83 3717 496667 5450 83 2194 17 3302 50333 4569 17 187 5 64 2200 83 4464 163333 7050 83 2194 17 3675 836667 5369 17 187 5 100 2200 83 5304 163333 8850 83 2194 17 4095 836667 6269 17 187 5 454 31006929 8 2007 Gateway Performance Serial Devices with 200 ms Response Time Time ms 12000 10000 4 8000 6000 4000 2000 6 20 T 40 60 Number of Registers 80 100 The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 200 Timeout EGX200 Time to Complete All Requests 1000 ms 1 Retry Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 2200 83 3694 163333 5400 83 2194 17 3640 836667 5294 17 187 5 16 2200 83 4044 163333 6150 83 2194 17 3815 836667 5669 17 187 5 32 2200 83 4417 496667 6950 83 2194 17 4002 50333 6069 17 187 5 64 2200 83 5164 163333 8550 83 2194 17 4375 836667 6869 17 187 5 100 2200 83 6004 163333 10350 83 2194 17 4795 83667 7769 17 187 5 31006929 8 2007 455 Gateway Performance
32. At a Glance Overview What s in this Chapter This appendix illustrates some performance measurements for devices with various response times when they communicate on a network through an EGX200 EGX400 or 174CEV30020 serial gateway Separate measurements are given for devices that communicate successfully and for the same devices when a single request failure is experienced This chapter contains the following sections Section Topic Page D 1 EGX200 Gateway Serial Server Response Time and Timeout 446 Measurements D 2 EGX400 Gateway Serial Server Response Time and Timeout 457 Measurements D 3 174CEV30020 Gateway Serial Server Response Time and 468 Timeout Measurements 31006929 8 2007 445 Gateway Performance D 1 EGX200 Gateway Serial Server Response Time and Timeout Measurements At a Glance Overview The performance of serial devices with response times of 50 ms 100 ms 200 ms and 500 ms are measured as they communicate across a network through an EGX200 Modbus to Ethernet gateway Network speeds of 9600 baud and 19 200 baud are considered Measurements are taken for both successful communications and for situations where a single request failure is experienced followed by a successful retry What s in this This section contains the following topics i Section Topic Page EGX200 Serial Server Response Times 447 EGX200 Serial Server Response Measure
33. PL7 level 2 TSX572 xx ETY module 32 PL7 level 4 TSX574 xx ETY module 64 When the Unity 2 0 CoPro uses an embedded port it can send 80 requests but it can accept only eight replies per scan 186 31006929 8 2007 Services Overview Premium Modbus Client Operations The Modbus client operates as follows Sequence Event 1 The application triggers the Modbus client block 2 The processor holds the request until the end of the current CPU scan 3 The ETY module checks if a TCP socket is connected to the destination device If a TCP socket is not connected the ETY module initializes a TCP socket and connects it to the destination device The ETY module sends the Modbus request The message travels across the network and a network delay occurs The Modbus server receives the message The Modbus server responds to the request The response travels across the network and a network delay occurs The ETY module receives the response O0 o NIOJ ae The response is passed back to the CPU at the next phase beginning of the next CPU scan 12 The next time the Modbus client block is reached in the code the response and any new data is available to the user application 13 The ETY leaves the TCP socket open for future use Note The ETY module leaves the TCP socket open until the other end closes it or the ETY module r
34. SNMP FTP Server x Xx xI Xx Xx Xx TFTP Server Telnet Server 1 For factory diagnostic purposes only The following table lists the Ethernet services supported by the Momentum M1E CPU modules Service 171CCC96020 171CCC96030 171CCC98020 171CCC98030 1 0 Scanner Xx xX xX X Modbus Server X X X X Modbus Client X X X X Global Data FDR Server FDR Client BootP Client X X X X Time Synchronization E mail Notification Web Embedded Xx X xX X Diagnostics 314 31006929 8 2007 Services Overview Momentum Ethernet Communications Modules Twido Devices Service 171CCC96020 171CCC96030 171CCC98020 171CCC98030 FactoryCast Web Server SNMP FTP Server TFTP Server The following table lists the Ethernet services supported by the Momentum Ethernet communications modules Service 170ENT11001 170ENT11002 O Scanner Modbus Server X X Modbus Client Global Data FDR Server FDR Client BootP Client x Xx Time Synchronization E mail Notification Web Embedded Diagnostics x lt FactoryCast Web Server SNMP FTP Server x Xx TFTP Server Telnet Server 1 For factory diagnostic purposes only The following table lists t
35. Troubleshooting Time Synchronization NTP Troubleshooting Table Cannot Obtain Time From Server Time Obtained Is Not Accurate These tables describe troubleshooting for time synchronization NTP see p 208 Topic Issue Time exchange format is incorrect configurations The server might implement SNTP broadcasts Schneider devices support only NTP SNTP request responses not broadcasts You can find this problem through the examination of device Cannot obtain time The server might be behind a firewall from the server Topic Problem Solution Server time is inaccurate or unstable The server time is not accurate especially if the network uses a PC instead of a dedicated server as an NTP server Windows PCs are the most likely to create this problem whereas a Linux PC or dedicated time server can solve it Network delays cause time inaccuracies Non uniform network loads can cause large delays in either the request or response message because NTP algorithms that calculate accurate times assume uniform network delays You can find this problem through the examination of network loads or by using an Ethernet packet capture tool to capture request and response packets Some devices also list delays on a diagnostics page To solve this problem move the server closer to the network client device through the elimination of routers and
36. e IGMP e IGMP snooping e GMRP IGMP is used by a router to establish multicast group membership and send a message to a particular network that has multicast members It stops forwarding the message when the last destination on a segment receives the message IGMP is used for the routing of multicast messages on the Internet as well as on a LAN IGMP operates at layer 3 it does not provide filtering at the switch level This method passively snoops on the registration information of IGMP packets to learn about group membership This information is used to compile a list of destinations to receive a given message IGMP filters at the switch level by listening to device and router messages and the IGMP Querier The querier is normally the router but if this is not the case an IGMP Querier is required GMRP is used to dynamically configure switch ports so that IP multicast traffic is forwarded only to those ports associated with IP multicast end users hosts A switch can exchange information about groups with other switches stop or prune broadcast traffic after all subscribed destinations have received the message as well as create and manage multicast groups GMRP operates in layer 2 with layer 2 devices such as Ethernet switches Transparent Ready supports GMRP NICs exchange information using a unique MAC address not an IP address To join a multicast group you must run an application on a host that can inform its networ
37. 153 Services Overview 3 1 Evaluating System Requirements At a Glance Overview This section provides an overview of Transparent Ready services that support Ethernet communications at each level within the plant It also describes how to evaluate your communications requirements and select the most appropriate services What s in this This section contains the following topics Section Topic Page Common Services at each Level in the Plant 155 Company Level Communication 156 Inter PLC Level 157 Field Level Communications 157 Communication Service Selection 158 Transparent Ready Support Services and Protocols 161 154 31006929 8 2007 Services Overview Common Services at each Level in the Plant Summary Transparent Ready industrial products can be integrated into architectures based on the universal Ethernet TCP IP network No additional interfaces are required The basic architecture below shows the various communication levels and functions required by industrial applications to meet the data exchange requirements of a plant Communications may take place at four levels e company level communication see p 156 between the control system products and the manufacturing execution system MES or enterprise resource planning ERP supervision or information systems e inter PLC level communication see p 157 for programming diagnostics and data transfer as well as
38. 31006929 8 2007 403 Modbus Server Performance Premium Modbus Server Throughput Capacity Unity v2 0 Performance The following chart shows the number of Modbus read register requests that may Measurements be answered by Premium CPUs in 1 CPU scan A read register request is a Modbus function code 3 command The minimum time to respond to a single Modbus request is one PLC scan cycle The throughput capacity of three PLCs is measured e a TSXP575634M CPU with a TSX ETY5103 Ethernet communications module e a TSXP575634M CPU with an embedded Ethernet port e a TSXP57304M CPU with a TSX ETY5103 Ethernet communications module 400 360 300 100 Number of Modbus Transactions s 50 100 150 200 250 Scan Time ms The table below shows the data points used to generate the graph represented above P575634M P575634M P57304M Embedded Port ETY5103 ETY5103 Scan Time Number of Modbus Transactions Second 10 400 400 300 20 300 400 300 50 320 400 160 100 160 200 120 200 80 100 60 404 31006929 8 2007 Modbus Client Response Times C At a Glance Overview What s in this Chapter This appendix illustrates some Modbus client response times for Premium and Quantum systems that use industrial Ethernet This chapter contains the following topics Topic Page Modbus Client Response Times Premium TSXP575634M 406
39. 4 1 1 2 2 3 4 5 1 1 2 2 3 4 6 1 1 2 3 3 5 7 1 1 2 3 4 6 8 1 1 2 4 4 6 9 1 1 2 4 5 7 10 1 1 2 4 6 8 11 1 1 2 5 6 9 12 1 1 2 5 7 10 13 1 2 2 6 7 10 14 1 2 3 6 8 11 15 1 3 3 6 8 12 16 1 3 3 7 9 13 17 2 3 3 7 9 14 31006929 8 2007 437 Modbus Client Performance At a CPU Scan Time of 50 ms 30 25 20 15 CPU Cycles 10 5 10 Communications Completed 15 20 The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 50 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 2 2 2 1 1 1 2 3 3 3 1 1 2 5 4 6 4 1 1 4 6 6 7 5 1 2 5 6 7 8 6 1 2 5 6 9 10 7 2 5 5 6 11 12 8 2 5 5 7 13 13 9 2 5 6 8 14 15 10 2 5 6 9 16 16 11 2 5 6 10 17 18 12 2 5 6 10 18 20 13 2 5 6 11 19 22 14 3 5 6 12 21 23 15 3 5 6 13 23 25 16 3 5 6 14 24 27 17 3 5 6 15 26 28 438 31006929 8 2007 Modbus Client Performance At a CPU Scan Time of 10 ms 140 7 120 4 100 CPU Cycles Communications Completed The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 10 lt 1 10 20 50 70 100 Requests Sent PLC Cycles
40. 515 transfer impedance of shield 31006929 8 2007 511 Earthing Grounding Procedures Definitions of Performance Parameters Introduction Nominal Impedance Return Loss Attenuation Insertion Loss The following discussion describes each of the specification parameters defined in the ISO IEC 11801 Impedance is a measure of the degree a component resists the flow of energy from a given source The impedance of a cable is important in determining the load placed on the source and the efficiency of the signal transmission A simple way to define nominal impedance is to measurer a component that does not reflect energy back to the transmitting source When a transmitting system sees the nominal impedance as its load all the energy that it transmits is absorbed by the receiving end If it does not see the nominal impedance part of the energy bounces back In an ideal system all the transmitted energy is absorbed by the receiving end Impedance is measured in Ohms Q Return loss is a measure of the reflected energy caused by impedance that mismatches in the cabling system impedance consistency If the system that transmits energy does not detect an impedance equal to the nominal impedance then there will be reflected energy that is the receiving end bounces back some energy In such cases there is an echo of the transmitted signal Return loss is measured in decibels or as a percentage of signal streng
41. 70 ms 76 cycles 100 ms 101 cycles 60 lt 1 ms 16 cycles 10 ms 21 cycles 20 ms 35 cycles 50 ms 89 cycles 70 ms 119 cycles 100 ms 163 cycles 412 31006929 8 2007 Modbus Client Performance Modbus Client Response Times Premium TSXP57304M Test Setup The following charts show Premium CPU response times where the client request block is triggered in PLC logic by reading data from a Modbus server The graphs represent the number of CPU cycles required for the PLC to complete all triggered Modbus client requests In all cases the PLC is a Premium TSXP57304M with an ETY5103 Ethernet communications module exec v3 10 The CPU logic scan times vary Modbus client response times are tracked with respect to six Modbus server response times e lt 1ms e 10ms e 20ms e 50ms e 70ms e 100 ms at a CPU Scan Time of 200 ms 193 7 184 174 164 f 154 144 134 124 o 114 K S 104 rs 94 ay 84 5 2 c 100ms __ 70 ms ons 20 ms 44 100 ms 50 ms 70 ms 4 t Z p roe 34 20 ms 2 14 0 i i i l i i i l 0 5 10 15 20 25 30 35 40 45 50 Communications Completed 31006929 8 2007 413 Modbus Client Performance A sampling of results in the chart follows Number of Requests Server Response Time CPU Cycles Needed To Complete
42. 991 333333 1844 666667 138 16 301 33333 1444 6667 2751 333333 269 66667 1191 33333 2244 666667 138 32 354 66667 1871 33333 3604 666667 296 33333 1404 66667 2671 333333 138 64 461 33333 2724 66667 5311 333333 349 66667 1831 33333 3524 666667 138 100 581 33333 3684 66667 7231 333333 409 66667 2311 33333 4484 666667 138 31006929 8 2007 471 Gateway Performance Serial Devices with 200 ms Response Time Time ms 10000 8000 7000 6000 Ol 00 120 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 200 CEV300200 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 351 33333 1844 66667 3551 333333 344 66667 1791 333333 3444 666667 138 16 401 33333 2244 66667 4351 333333 369 66667 1991 33333 3844 666667 138 32 454 66667 2671 33333 5204 666667 396 33333 2204 66667 4271 333333 138 64 561 33333 3524 66667 6911 333333 449 66667 2631 33333 5124 666667 138 100 681 33333 4484 66667 8831 333333 509 66667 3111 33333 6084 666667 138 472 31006929 8 2007 Gateway Performance Serial Devices with 500 ms R
43. A dual ring has all the features of a single ring with more fault tolerance It comprises infrastructure components connected together with multiple rings Each device is connected to two infrastructure components Each infrastructure component is connected to a separate ring When a single link or infrastructure device fails all other devices can still communicate Dual ring topologies used in automation environments have additional features not always found in typical data communications environments For example hot standby links are used between rings When a link fails the standby becomes active and prevents any interruption in network communications Watchdog packets are sent out to inactive connections and they create logs if the connection remains inactive The watchdog packets create log entries that are monitored by the network administrator Advantages Disadvantages Redundancy the failure of multiple devices or Cost compared to a single ring since cables does not cause the network to fail the amount of equipment is doubled Separate power supplies can be used for each ring The need to regularly monitor unused Multiple interfaces within a device can connect the links so that they are known to be device to different rings so that the flooding of one healthy in the event that they are ring with collisions or broadcast traffic does not needed cause the system to fail 31006929 8 2007 47
44. Bootstrap Protocol as its name suggests allows a workstation to configure itself without a hard drive or floppy disk The workstation can discover its own IP address the IP of a server and a file to be loaded into memory to boot the machine DHCP assigns a different address to a device when it requests one The software rather than the administrator as in static addressing keeps track of the IP addresses 134 31006929 8 2007 Planning and Layout Multicasting Considerations Summary On the Internet IP Multicasting Transport IP Multicast Addresses IP multicast a method of selectively sending messages promoted by an industry consortium of prominent companies is an up and coming technology that will be used increasingly for e monitoring manufacturing and other types of real time information sensor equipment or security systems e announcements network time multicast session schedules random numbers keys configuration updates etc e file distribution and caching Web site content executable binaries e scheduled distribution of audio and video e push media news headlines weather updates sports scores etc You should make sure that your router and or switches support multicast your workstations are configured to join a multicast group and that you have installed any specific applications needed to receive the multicast The UDP protocol is used for IP multicasting The multicast address sele
45. Device ieee nput a la ar EOS CPU logic Ca 3 lt EOS EN Output A X Premium ETY CPU gt Unity CoPro or ETY running PL7 or Unity 1 0 running Unity 2 0 ETY Remote CPU CoPro Remote Device Device Input P Input a lq Pra 4 cos q_ CPU logic EOS m gt Output a2 ES Output e A Quantum PLC with an NOE Ethernet communications module exchanges data with a remote device once per CPU scan This limits the effective repetition rate to a value greater than one PLC scan cycle e A Premium PLC with an ETY Ethernet communications module in a PL7 or Unity 1 0 environment exchanges data at the configured repetition rate assuming that the device can answer within this time period and exchanges the data with the CPU on each EOS cycle The output cycle requires an additional CPU scan to transfer the data to the ETY module e A Unity CoPro CPU with an embedded Ethernet port or a Premium CPU with an ETY module in a Unity environment transfers data at the configured repetition rate assuming that the device is able to answer within this time period Note Data values may be exchanged with the remote device multiple times per CPU scan The last value read from the remote device is sent to the CPU at the next EOS and the value written to the remote device is the value from the CPU at the previous EOS 31006929 8 2007 175 Services Overview Some Comm
46. IEC 60068 2 6 Environmental testing Part 2 Environment Tests Test Fc Vibration sinusoidal Light Duty EN 60068 2 6 Heavy Industrial 5g 10 500Hz_ IEC 60068 2 6 Environmental testing Part 2 Environment Tests Test Fc Vibration sinusoidal Heavy Duty EN 60068 2 6 31006929 8 2007 69 Planning and Layout Tensile Strength Requirements Flexing Requirements Crush Requirements The following table shows the recommended degree of tensile strength acceptable for industrial Ethernet cables Environment Tensile Strength Requirement Reference Light Industrial Environment Light Duty 75 100 200 N for 1 min IEC 60966 1 Heavy Industrial Environment 100 200 N for 1 min IEC 60966 1 Heavy Duty The following table shows the recommended degrees of flexing allowable for industrial Ethernet cables Environment Flexing Requirement Light Industrial Environment Light Duty 5 N 1000 operations 90 degrees Heavy Industrial Environment Heavy Duty 5 N 1000 operations 90 degrees The following table shows the recommended allowable degrees of crush for an industrial Ethernet cable Environment Crush Requirement Light Industrial Environment Light Duty Heavy Industrial Environment Heavy Duty ISO IEC is writing a draft standard document which has not yet been released 70 31006929 8 2007
47. It functions the same as a router but at an increased speed 60 31006929 8 2007 Planning and Layout Other LAN Considerations Summary Full Duplex vs Half Duplex When to Use a Switch Bandwidth Below are some additional considerations for planning a robust industrial application network Schneider Electric recommends the use of full duplex switches wherever possible Full duplex switches e give greater bandwidth 100 MB in both directions on certain networks e allow a device to send responses while receiving additional requests or other traffic e result in less delays and errors with a device Switches should always be used in the design of your new network They offer more intelligence than hubs at an equal or lesser cost The industrial switches available today work reliably under extreme conditions such as with electromagnetic interference high operating temperatures and heavy mechanical loads Protect industrial switches by using field attachable connectors up to IP67 see p 74 and redundant ring cabling 10 MB of bandwidth can be used for smaller end devices but not for links to PLC SCADA or to main network links 100 MB is adequate for most automation systems 1 GB is useful for the main network link This capacity is not required but ensures that more bandwidth is available if needed 1 GB is necessary if other services share the network with the automation system
48. Network Monitoring via Module Status Fully redundant systems have the following limitations e increased cost of components e the need to modify systems outside of the hot standby PLC e system complexity The status of the local Ethernet communications module can be monitored by the PLC program using the MSTR or MBP_MSTR block to read local statistics These blocks provide information on the health of the module and of the Ethernet link from the module to the first hub or switch Word 3 of the returned data is defined as the board status Bit Definition 15 12 Module type 11 Reserved 10 0 half duplex 1 full duplex 9 0 not configured 1 configured 8 0 PLC not running 1 PLC NOE running 7 0 Link LED off 1 Link LED on 6 0 Appl LED off 1 Appl LED on 5 0 twisted pair 1 fiber 4 0 10 Mbit 1 100 Mbit 3 0 Reserved Bit 7 Link LED on can be monitored to determine the status of the connection from the module to the local hub or switch If the Ethernet module is faulty an error is returned by the Read Local Statistics command Note The Read Local Statistics command monitors only the local connection It does not ensure that the full network required to communicate to a remote device such as additional hubs or switches that are used to connect to the other device is intact It does not check the operation of the remote device Device monitoring
49. SNMP Device SNMP v1 SNMP v2 SNMP v3 MIB II TFprivate MIB TSXP571634M X X X TSXP572634M xX X X TSXP573634M X X X TSXP574634M X X X TSXP575634M X X X TSXETY4103 X X xX TSXETY110WS X X xX TSXETY5103 X X X TSXWMY100 X X X FTP Device Firmware Web Files Security FDR Support TSXP571634M X X X X TSXP572634M X xX X xX TSXP573634M X X X X TSXP574634M X X X X TSXP575634M X xX X X TSXETY4103 X xX X X TSXETY110WS X xX X TSXETY5103 X xX X X TSXWMY100 X xX X 31006929 8 2007 251 Services Overview TFTP Telnet Device FDR Support TSXP571634M X TSXP572634M X TSXP573634M X TSXP574634M x TSXP575634M X TSXETY4103 X TSXETY110WS X TSXETY5103 X TSXWMY100 X Device Configuration Diagnostics Security Levels of Security TSXP571634M X X x2 TSXP572634M X X x2 TSXP573634M X X x2 TSXP574634M X X x2 TSXP575634M X X x2 TSXETY4103 X X x2 TSXETY110WS X X x2 TSXETY5103 X X x2 TSXWMY 100 X X x2 1 For factory use only 2 multiple passwords 252 31006929 8 2007 Services Overview Other Services Supported by TSX Micro Devices FTP Other Services Supported by Momentum Devices SNMP FTP Telnet Device Firmware Web Files Security FDR Support TSXETZ410 X X X Xx TSXETZ510 X X X X
50. The color coding specification is independent of the type of network Refer to the EIA TIA 568B standard for all pinout specifications The colors defined for the 4 pairs 8 cables are Pair 1 Blue White with Blue stripe Pair 2 Orange White with Orange stripe Pair 3 Green White with Green stripe Pair 4 Brown White with Brown stripe The pinout color code specified for the RJ45 connector is shown below PIN 1 Orange striped 2 2 Orange eg 3 Green Stripped Sannn 4 Blue striped aona jana 5 Blue a gee 3 6 Green 7 Brown Striped gxxeeeee 8 Brown Wire Pair RJS Jack T568B AT amp T Schneider recommends that the jacket of the cable be green RAL 6018 80 31006929 8 2007 Planning and Layout Difference The difference between the color codes is that pair 2 orange and pair 3 green are between EIA TIA interchanged The EIA TIA 568B standard is the most widely used 568A and EIA TIA 303 Note There is no difference between the two wiring schemes in connectivity or performance when connected from one modular device to another jack to Patch panel RJ 45 to RJ 45 etc so long as the two devices are wired for the same scheme A or B Also refer to Installation see p 93 for more detailed information regarding the installation of cabling 31006929 8 2007 81 Planning and Layout Fiber Optic Cabling Summary
51. Unfortunately the two Ethernet cards using different IP networks even if they are connected to the same physical network cause problems communicating with remote devices The devices may not be able to communicate on both networks at the same time Two complete networks must be constructed and all the devices must be connected to both networks You must determine which network is active through network management 290 31006929 8 2007 Services Overview The following illustration shows a PC with two Ethernet cards going to the same switch and a PLC with two ETY modules connected to the switch 192 168 2 2 192 168 1 1 192 168 1 2 1 A decision block inside the SCADA or PC program 2 Network B 3 Network A Two independent networks supply a high level of redundancy but a decision block must be included in the SCADA or PC program to determine which network to use at any given time 31006929 8 2007 291 Services Overview Redundancy within a SCADA System Summary Multiple levels of redundancy are available within a SCADA system For plant communications the SCADA system should operate so that only the primary I O server exchanges data with the field devices This provides the following benefits e greatly reduced communications load on the field devices resulting in faster response times for the entire system e reduced network traffic at the interdevice level of the plant e more efficient network
52. You must test a copper installation for correct installation and performance conformance as defined by the ISO IEC 11801 standard For testing the installation and performance of permanent links and channels Schneider Electric recommends that you use market available tools and testers Some of these tools are described below Schneider Electric recommends the use of appropriate tools to certify copper cabling installations and performance The OMNIscanner 2 and the DSP 4000 are examples of standard tools Both are used to test certify and document high speed copper and fiber networks They are available from Fluke Networks The following table compares the features of the two testers The testers have complementary functionality To measure and record the specification parameters required by the ISO IEC 11801 standard you must use both tools DSP 4300 OMNIScanner 1 Schematic diagnostics display x Shows crosstalk vs length x Shows NEXT vs length x Shows NEXT phase information x Shows impedance vs length X Shows return loss vs length Includes pass fail S bands Time domain plots can be saved Magnitude and phase information can be exported 120 31006929 8 2007 Planning and Layout 2 7 Additional Considerations for Designing a Transparent Ready Industrial Ethernet Network At a Glance Overview Th
53. against the harmful intrusion of water and moisture in varying forms Second Digit Degree of protection Moisture No special protection Protection from dripping water Protection from vertically dripping water Protection from sprayed water Protection from splashed water Protection from water projected from a nozzle Protection against heavy seas or powerful jets of water Protection against immersion ONO a BR w n o Protection against complete continuous submersion in water The end user must specify submersion depth and time The requirement must be greater than IP67 74 31006929 8 2007 Planning and Layout Recommended Degrees of Protection for Industrial Ethernet A third digit is sometimes used if there is only one class of protection and an X is used for one of the digits For example IPxI indicates that the equipment is protected against dripping water only Environment Degree of Protection Reference Recommended Light Industrial Light Duty IP20 IEC 60529 Degrees of protection provided by enclosures IP code EN 60529 Heavy Industrial IP67 IEC 60529 Degrees of protection provided by enclosures IP Code EN 60529 31006929 8 2007 75 Planning and Layout Electromagnetic Emission and Immunity Requirements Introduction There are two types of EMC requirement e emission h
54. e performance issues e environmental interference e identify sources by e device query and response times e device incompatibility e identify resolutions such as e device replacement e system redesign e work arounds for an unfixable problem A set of appendixes containing the results of performance measurements is presented at the end of the guide The results compare the response times and throughput rates of different Transparent Ready devices that use some of the key network services There is also a detailed section on Standards 31006929 8 2007 25 Transparent Ready 26 31006929 8 2007 Physical Planning Design and Installation of a Transparent 2 Ready Industrial Ethernet Network At a Glance Overview What s in this Chapter This chapter discusses the topics concerning Ethernet that an automation or control engineer should consider when planning installing and verifying a Transparent Ready industrial Ethernet network In designing a Transparent Ready industrial Ethernet network to fit your facility you should have a general knowledge of network layout criteria for choosing components issues pertinent to the design process and the existing standards for office network components and layout that guide industrial network development You may consult your IT personnel or a variety of written and electronic sources for more detailed information The planning section provides a description
55. in s 30 20 10 8 2 16 32 48 64 Number of Stations 31006929 8 2007 203 Services Overview 3 5 Faulty Device Replacement At a Glance Overview When the FDR service is supported in a field device you can easily and reliably replace the device if it fails When the replacement device is installed it is automatically reconfigured with the operating parameters and IP address of the failed device What s in this This section contains the following topics Section z Topic Page Faulty Device Replacement 205 Devices that Support the FDR Services 207 204 31006929 8 2007 Services Overview Faulty Device Replacement Summary The FDR service uses a central FDR server to store network parameters and the operating parameters of devices on the network If a device fails the server automatically configures the replacement device with the identical parameters as the failed device The FDR service removes the need for service personnel to keep configuration records on hand and reduces the possibility of human error in entering the new configuration TFTP Server 84 16 01 03 DHCP Server FDR server server configuration operating parameter file transferred to the FDR client FDR client replacement device rolename assignment akhond 31006929 8 2007 205 Services Overview FDR Components When to Use FDR
56. is a slightly slower process than cut through but it ensures that all bad or misaligned packets are eliminated from the network by the switching device shielded twisted pair Common transmission medium that consists of a receive RX and a transmit TX wire twisted together to reduce crosstalk The shield is a braided outer sheath Project file extension for Unity Pro software application A interconnected but separate portion of a network that shares a network address with other portions of the network Used for security and performance See CIDR A multiport Ethernet device designed to increase network performance by allowing only essential traffic on the attached individual Ethernet segments Packets are filtered or forwarded based upon their source and destination addresses An Ethernet hub with integrated MAC layer bridging or switching capability that provides each port with 10 Mb s of bandwidth Separate transmissions can occur on each port of the switching hub The switch filters traffic based on destination MAC address A logical network consisting of several different LAN emulation domains controlled through and intelligent network management application Hubs that use intelligent Ethernet switching technology to interconnect multiple Ethernet LANs and higher speed LANs such as FDDI synchronize A packet type used by TCP to synchronize sequence numbers on two computers beginning a new connection A message that ackno
57. work area For a cabling installation to conform to the ISO IEC 11801 standard the configuration must connect the following subsystems of a cabling system e campus backbone campus uses building distributors e building backbone every building has a building distributor e horizontal cabling every floor has a floor distributor 36 31006929 8 2007 Planning and Layout Structure of Cabling Systems The generic cabling system defined by the ISO IEC 11801 standard is a hierarchical star structure see p 44 The diagram below shows a central campus distributor and a campus backbone cabling system linking multiple building distributors Each building is required to have at least one building distributor Each building distributor connects to the central campus distributor using a star topology The campus distributor becomes the central communication unit As a backup and safety precaution you should create redundant links between buildings Within a building every floor has its own floor distributor that serves up to 2000 m2 of office space 1 Central campus distributor 2 Campus backbone cabling 3 Building distributor In a campus that has only one building the primary distribution point becomes the building distributor in that building However it is possible for a large building to act as a campus and have one campus backbone with several building distributors The number of subsystems and type of
58. 0 0 0 10 255 255 255 10 8 prefix 172 16 0 0 172 31 255 255 172 16 12 prefix 192 168 0 0 192 168 255 255 192 168 16 prefix There are three types of special addresses that should be mentioned e broadcast e loopback e network A broadcast message usually used for network management and diagnostic purposes is addressed to all stations on the network The destination address ina broadcast message is made up of all 1s 255 255 255 255 A loopback address is used to test the implementation of the TCP IP protocol on a host The lower layers are bypassed by sending to a loopback address This allows the higher layers IP and above to be tested without exposing problems at the lower layers 127 0 0 1 is the address typically used for loopback testing As described in the previous section network address refers to the network portion of an IP Internet Protocol address 31006929 8 2007 131 Planning and Layout Sufficient Addresses Subnetting In planning for your network you should anticipate the need for these addresses for the gateway one address for broadcast for the number of services for future devices added to the network Tools can be found on the Internet to help calculate the number of addresses your network requires Forming subnets divides a large network into more manageable segments it can allow you to expand the number of networks while using only the single IP address You need
59. 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 1 1 2 1 1 1 1 1 1 3 1 1 1 1 1 1 4 1 1 1 1 2 2 5 1 1 1 1 2 2 6 1 1 1 2 2 3 7 1 1 1 2 2 3 8 1 1 1 2 3 4 9 1 1 1 2 3 4 10 1 1 1 2 4 5 11 1 1 2 3 4 5 12 1 1 2 3 4 5 13 1 1 2 3 4 6 14 1 1 2 3 5 6 15 1 1 2 4 5 6 16 1 1 2 4 5 7 17 2 2 2 4 6 8 31006929 8 2007 441 Modbus Client Performance At a CPU Scan Time of 100 ms CPU Cycles 4 5 6 7 8 9 10 Communications Completed The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 100 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 1 1 2 1 1 1 1 1 2 3 1 1 1 1 2 3 4 1 1 1 2 2 3 5 1 1 1 2 3 4 6 1 1 2 3 3 5 7 1 1 2 3 4 6 8 1 1 2 3 4 6 9 1 1 2 4 5 7 10 1 1 2 4 6 8 11 1 1 2 4 6 9 12 1 2 2 5 7 9 13 1 2 2 6 7 10 14 1 2 2 6 8 11 15 1 3 3 6 9 12 16 1 3 3 6 9 13 17 2 3 3 7 9 14 442 31006929 8 2007 Modbus Client Performance At a CPU Scan Time of 50 ms 30 CPU Cycles 0 1 2 3 4 5 6 7 8 9 10 11 12 143 14 145 146 17 48 Communications Completed The table below shows the dat
60. 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 235 3333333 678 6666667 1185 333333 228 6666667 625 33333333 1078 666667 172 16 285 3333333 1078 666667 1985 333333 253 6666667 825 3333333 1478 666667 172 32 338 6666667 1505 333333 2838 666667 280 3333333 1038 6666667 1905 333333 172 64 445 3333333 2358 666667 4545 333333 333 6666667 1465 333333 2758 666667 172 100 565 3333333 3318 666667 6465 333333 393 6666667 1945 333333 3718 666667 172 31006929 8 2007 459 Gateway Performance Serial Devices with 100 ms 8000 4 Response Time Time ms 7000 6000 5000 4 4000 4 3000 2000 lt 1000 20 40 Number of Regi 60 80 sters 120 The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 100 EGX200 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 285 3333333 1078 666667 1985 333333 278 6666667 1025 3333333 1878 666667 172 16 335 3333333 1478 666667 2785 333333 303 6666667 1225 3333333 2278 666667 172 32 388 6666667 1905 333333 3638 666667 330 3333333 1438 6666667 2705 333333 172 64 495 3333333 2758 666667 5345 333333 383 6666667
61. 10 2 4 6 9 13 19 11 3 4 6 10 14 20 12 3 4 6 11 15 21 13 3 5 6 12 16 23 14 3 5 6 13 18 25 15 3 5 6 14 19 27 16 3 5 6 15 20 29 17 3 5 7 16 22 31 31006929 8 2007 433 Modbus Client Performance At a CPU Scan Time of 10 ms CPU Cycles Communications Completed The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 10 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 6 4 4 5 5 8 2 6 5 5 8 10 15 3 7 5 6 16 18 28 4 7 5 6 18 19 29 5 7 6 7 21 25 36 6 7 6 19 26 30 43 7 7 7 21 28 35 51 8 7 7 21 30 41 58 9 8 12 21 34 46 66 10 9 12 21 38 51 74 11 9 14 22 42 57 82 12 10 14 22 46 63 91 13 11 16 23 50 69 99 14 12 17 24 55 75 108 15 13 19 24 59 81 117 16 13 22 26 64 88 126 17 14 23 28 68 95 136 434 31006929 8 2007 Modbus Client Performance Modbus Client Response Times Quantum 140 CPU43412A with a 140 NOE77101 Ethernet Communications Module Test Setup The following charts show Modbus client response times where the client request block is triggered in PLC logic by reading data from a Modbus server The graphs represent the number of CPU cycles required for the PLC to complete all triggered Modbus client requests In all cases the PLC is a Quantum 140 CPU43412A with a 140 NOE77101 Ethernet communicatio
62. 101 S SCADA back up watchdog 294 blocking technique for efficient communication 280 client server model 276 communication to a redundant device 293 exception reporting 277 for a Quantum hot standby system 295 stages of communication 276 standalone model 275 troubleshooting 364 watchdog to Quantum PLC implementation 300 SCADA communication on a single socket that supports multiple requests 283 on a single socket that supports one request at a time 282 on multiple sockets that support one request at a time 284 SCADA to SCADA communication 285 security access control list 150 access points 151 firewall 150 firewall setup 150 for an Ethernet system 149 password 149 physical access 149 PLC access control 151 policy 149 port 151 VPN 152 WEP 152 wireless 151 selection standards 32 self healing ring topology 53 sensitivity in EMC performance 99 server in a faulty device replacement operation 206 service compatibility 165 31006929 8 2007 553 Index services Advantys STB device support 316 Altivar ATV 38 58 variable speed drive device support 317 available for a Quantum hot standby system 302 ConneXium cabling system device support 318 electronic mail notification 159 218 embedded diagnostics 160 FactoryCast HMI Web server 237 FactoryCast Web server 231 faulty device replacement 159 205 file transfer protocol 243 for field level communication 157 for inter PLC
63. 111 commercial installations 112 component testing 112 documentation 112 fiber optic 82 fiber optic standards 82 fiber optic technical description 82 fiber optic types 83 85 fiber optic vs copper 85 labels 112 test data 113 cabling planning standards 32 cabling shield how to ground 507 cabling subsystems 36 cabling system elements 36 calculation functions in a FactoryCast HMI Web server operation 240 campus backbone 36 CAT 1 unshielded 1 Mb s twisted pair copper cable 78 CAT 2 unshielded 4 Mb s twisted pair copper cable 78 CAT 3 16 Mb s twisted pair copper cable 78 CAT 4 20 Mb s twisted pair copper cable 78 CAT 5 100 Mb s twisted pair copper cable 78 CAT 5E enhanced CAT 5 350 MHz twisted pair copper cable 79 CAT 6 400 MHz twisted pair copper cable 79 CAT 7 500 700 MHz twisted pair copper cable 79 changeover in a Quantum hot standby system 301 UDP message in a Quantum hot standby system 302 channel 118 circuit switching in an Ethernet system 62 client in a faulty device replacement operation 206 client communication between an I O server and a SCADA display 285 climate protection requirements humidity 72 operating temperature 71 storage temperature 71 UV exposure 72 collision domains in an Ethernet system 56 collision management 56 combining data transfers 165 commercial installations cabling 112 common bonding network 96 company level communication 155 Transparent R
64. 113 testing a copper installation 509 TFTP trivial file transfer protocol 161 time synchronization service selection 159 troubleshooting 362 tools for building Ethernet copper cables 108 110 topologies bus 43 daisy chain 45 dual ring 47 Ethernet bus 49 Ethernet daisy chain 50 Ethernet ring 51 Ethernet star 50 mesh 48 52 ring 46 self healing ring 53 star 44 traffic congestion on an Ethernet system 347 transceiver in an Ethernet system 60 transfer services for plant data 162 Transparent Ready defined 16 strategy 18 system elements 24 Transparent Ready model based on OSI 127 transparent remote communication 155 transport layer in the TCP IP model 125 of the Transparent Ready model 129 trivial file transfer protocol 246 ConneXium device support 255 Premium device support 252 Quantum device support 249 31006929 8 2007 555 Index troubleshooting an Ethernet system 343 bridge 365 Ethernet remote access 352 FTP 359 HMI 364 intermittent connections in an Ethernet system 350 logical connections in an Ethernet system 347 lost packets 366 367 NTP 362 packet capture 369 physical connections in an Ethernet system 346 physical connections on an Ethernet network 348 SCADA 364 services 354 slow connections on an Ethernet system 351 slow response 364 SMTP 361 SNMP 358 Telnet 359 time synchronization 362 traffic congestion in an
65. 160 characters that can be sent to a wireless device 31006929 8 2007 535 Glossary SMTP SNA SNMP SNP SNTP SOAP socket SONET spanning tree spanning tree algorithm spoofing SQL simple mail transfer protocol Internet standard used to send and receive email messages systems network architecture IBM s layered protocols for mainframe communications simple network management protocol A 3 part protocol comprising structure of management information SMI management information base MIB and the protocol itself The SMI and MIB define and store the set of managed entities SNMP itself conveys information to and from these entities The public domain standard is based on the operational experience of TCP IP Internet works within DARPA NSFnet A TCP IP host running an SNMP application to query other nodes for network related statistics and error conditions The other hosts which provide SNMP agents respond to these queries and allow a single host to gather network statistics from many other network nodes sub network protocol ATCP IP protocol residing in the sub network layer below IP It provides data transfer through the local sub net In some systems an adapter module must be inserted between IP and the SNP to reconcile their dissimilar interfaces simple network time protocol A simplified version of NTP used to synchronize the clocks of computer systems simple object access
66. 184 for the file transfer protocol 249 251 253 254 255 for the simple network management protocol 249 251 253 254 255 for the Telnet service 250 252 253 255 for the trivial file transfer protocol 249 252 255 services for Advantys STB 316 services for Altivar ATV 38 58 variable speed drives 317 services for ConneXium cabling systems 318 services for Momentum Ethernet communication modules 315 services for Momentum M1E processors 314 services for Power Logic gateways 317 services for Premium CPUs 312 services for Premium Ethernet modules 313 services for Quantum 312 services for TSX Micro communication modules 314 services for Twido 315 diagnostic services 164 diagnostic word for I O scanning 173 dial up for remote control of a PC 142 dial up services in an Ethernet system 64 disable I O scanning 172 distribution group in a global data operation 199 31006929 8 2007 545 Index documentation cabling 112 DSP 4000 certification tool for copper cable installations and performance 120 dual ring topology 47 dynamic pages in a Web server operation 226 E earth plane 96 earthing to combat EMI in Ethernet networks 94 earthing conductors 95 earthing connection for cable shielding 504 procedure 502 earthing connections recommendations 500 earthing main conductor 95 earthing ring bus 96 earthing system components 95 effective repetition rates for I O scanning 174 ele
67. 226 Devices that Support Standard Web Server Services 5 229 FactoryCast Web Server 0 0 0 0 cee teens 230 FactoryCast Web Server Operation 000 c eee eee eee 233 Devices that Support FactoryCast Web Server Services 235 FactoryCast HMI Web Server 0000 e eee ete tee 236 FactoryCast HMI Web Services 0 00 cee eee eee 237 Devices that Support The FactoryCast HMI Web Service 241 Other Services 00 00 cece tenes 242 PPSCnVICC ie eet EE te iad wl atlanta de chia EEE EEEE 243 SNMP SCIvViCO eedi ieena daia a e o a etapa ada 244 TEETE SEVICE n anaras Ene aLa E fa aoe ate tala estan eae a NERT a EAA 246 Telnet S6rviGe m i eera er E ePaper ee ee aA 247 Quantum Device Support for Other Services s a s asasan arrn 249 3 12 3 13 3 14 3 15 3 16 3 17 Chapter 4 41 Other Services Supported by Premium Devices 0 005 251 Other Services Supported by TSX Micro Devices 00 253 Other Services Supported by Momentum Devices 2 005 253 Other Services Supported by Advantys STB Devices 254 Other Services Supported by Power Logic Gateways Bridges 254 Other Services Supported by ConneXium Cabling Systems 255 OPC Factory Severs ees 25 eee oe oe sit Fi pce eo Re ees 256 OFRSSe IvVICES eradan ae a A A D ince ene fA te Dee Ee ae 261 OFS Pemorm
68. 250 4 200 4 Time ms 150 4 100 4 50 4 1 16 devices 0 50 100 PLC Scan Time ms 150 200 The bottom curve shows that the response times for 1 to 16 devices are within 1 ms of each other The response times for 32 devices are 9 to 10 ms longer initially as scan time increases the difference in response times becomes smaller The table below shows the data used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Local Output ms TSXP575634M v2 0 10 ms 20 ms 50 ms 100 ms 200 ms Embedded Ethernet Port v2 0 Scan Scan Scan Scan Scan 1 device 23 42 102 201 402 8 devices 23 42 102 201 402 16 devices 24 43 103 202 403 32 devices 33 52 110 208 405 380 31006929 8 2007 I O Scanner Performance TSXP575634M The TSXP575634M CPU used for the following measurements is at version 2 0 and CPU with a the TSXETY5103 Ethernet communications module is at version 3 1 TSXETY5103 Module 450 7 400 A 350 4 ed 300 4 e 250 200 Boa Time ms 150 4 100 4 50 4 a 1 16 devices 0 i l l i 0 50 100 150 200 PLC Scan Time ms The bottom curve shows that the response times for 1 to 16 devices are within 3 ms of each other The response times for 32 devices are 6 to 9 ms longer initially as scan time increases the difference in response times be
69. 3 3 7 1 2 2 2 3 4 8 1 2 2 2 3 4 9 1 2 2 3 4 5 10 1 2 2 3 4 5 11 1 2 2 3 4 6 12 1 2 3 3 5 6 13 1 2 3 4 5 7 14 1 2 3 4 5 7 15 1 2 3 4 6 8 16 1 2 3 4 6 8 17 2 2 3 5 6 8 31006929 8 2007 431 Modbus Client Performance At a CPU Scan Time of 100 ms CPU Cycles 4 6 Communications Completed 8 10 The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 100 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 1 2 2 1 1 1 1 2 2 3 1 1 1 2 3 4 4 1 1 2 4 3 4 5 1 1 2 4 4 5 6 1 2 3 4 4 6 7 1 2 3 4 5 7 8 1 2 4 4 6 8 9 1 2 4 5 6 9 10 1 2 4 5 7 10 11 2 3 4 6 8 11 12 2 3 4 6 8 12 13 2 3 4 7 9 13 14 2 3 4 7 10 13 15 2 3 4 7 10 14 16 2 3 4 8 11 15 17 2 3 4 8 12 16 432 31006929 8 2007 Modbus Client Performance At a CPU Scan Time of 50 ms CPU Cycles 0 2 4 6 8 10 12 14 16 18 Communications Completed The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 50 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 2 2 2 1 1 1 2 3 4 3 1 1 2 4 6 7 4 2 2 3 5 6 7 5 2 2 4 5 7 9 6 2 2 4 6 8 11 7 2 3 4 7 9 13 8 2 3 5 8 10 14 9 2 3 5 8 11 16
70. 51 67 99 14 13 17 24 56 73 109 15 14 20 24 59 81 117 16 14 22 25 64 89 124 17 14 23 28 67 96 134 31006929 8 2007 429 Modbus Client Performance Modbus Client Response Times Quantum 140 CPU65150 with a 140 NOE77111 Ethernet Communications Module Test Setup The following charts show Quantum PLC response times where the client request block is triggered in PLC logic by reading data from a Modbus server The graphs represent the number of CPU cycles required for the PLC to complete all triggered Modbus client requests In all cases the PLC is a Quantum 140 CPU65150 with a 140 NOE77111 Ethernet communications module The CPU logic scan times vary Modbus client response times are tracked with respect to six Modbus server response times lt 1ms 10 ms 20 ms 50 ms 70 ms e 100 ms 430 31006929 8 2007 Modbus Client Performance At a CPU Scan Time of 200 ms 9 CPU Cycles 100 ms Communications Completed The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 200 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 1 1 2 1 1 1 1 1 2 3 1 1 1 2 2 2 4 1 1 2 2 2 2 5 1 1 2 2 3 3 6 1 2 2 2
71. 512 Creer te ee a ae a ee eae ee E ee eer eat 517 Vector Tt eee eee eee eo Te E ee ee ee ee 543 Safety Information A Important Information NOTICE PLEASE NOTE Read these instructions carefully and look at the equipment to become familiar with the device before trying to install operate or maintain it The following special messages may appear throughout this documentation or on the equipment to warn of potential hazards or to call attention to information that clarifies or simplifies a procedure that an electrical hazard exists which will result in personal injury if the The addition of this symbol to a Danger or Warning safety label indicates A instructions are not followed injury hazards Obey all safety messages that follow this symbol to avoid This is the safety alert symbol It is used to alert you to potential personal A possible injury or death A DANGER DANGER indicates an imminently hazardous situation which if not avoided will result in death or serious injury A WARNING WARNING indicates a potentially hazardous situation which if not avoided can result in death serious injury or equipment damage A CAUTION CAUTION indicates a potentially hazardous situation which if not avoided can result in injury or equipment damage Electrical equipment should be installed operated serviced and maintained only by qualified personnel No responsibility is assum
72. 55 60 Requests Sent A sampling of results in the chart follows Number of Requests Server Response Time CPU Cycles Needed To Complete 1 7 lt 1 100 ms 2 cycles 8 70 100 ms 3 cycles 10 50 ms 3 cycles 29 100 ms 4 cycles 33 70 ms 4 cycles 100 ms 5 cycles 38 50 ms 4 cycles 70 ms 5 cycles 100 ms 6 cycles 41 20 ms 3 cycles 42 100 ms 7 cycles 46 50 ms 5 cycles 70 ms 6 cycles 48 10 ms 3 cycles 55 50 ms 6 cycles 70 ms 7 cycles 100 ms 10 cycles 60 100 ms 11 cycles 31006929 8 2007 407 Modbus Client Performance at a CPU Scan Time of 100 ms CPU Cycles 100 ms 70 ms 50 ms 10 ms 100 ms 50 ms 70 ms 20 ms 5 10 15 20 25 30 35 Communications Completed A sampling of results in the chart follows 45 Number of Requests Server Response Time CPU Cycles Needed To Complete 1 4 lt 1 100 ms 2 cycles 5 100 ms 3 cycles 7 20 70 ms 3 cycles 16 100 ms 4 cycles 18 10 ms 3 cycles 22 70 ms 4 cycles 24 100 ms 5 cycles 29 50 ms 4 cycles 70 ms 5 cycles 31 100 ms 6 cycles 33 lt 1 ms 3 cycles 70 ms 6 cycles 100 ms 7 cycles 34 100 ms 8 cycles 38 50 ms 6 cycles 39 70 ms 8 cycles 100 ms 9 cycles 408 31006929 8 2007 Modbus Client Performance at a CPU Scan Time of 50 ms
73. 8 eight pins or electrical connections that are numbered 1 8 from left to right For Ethernet 10Base T and 100Base TX the RJ45 pins are used as follows RJ45 pin Ethernet Signal 1 Transmit TX 2 Transmit TX 3 Receive RX 4 Unused 5 Unused 6 Receive RX 7 Unused 8 Unused When making Ethernet cables if you plan to only use 2 pairs 4 conductors you connect all of them If you use 4 pairs 8 conductors Schneider recommends that you connect them as suggested in the EIA TIA 568B specification even though pins 4 5 7 and 8 do not have signals assigned For the recommended color coding based on the TIA EIA 568B standard please see p 80 Note When you use CAT 5 5e cabling pins 4 5 6 and 8 are not required for 10Base T or 100Base TX physical layers 88 31006929 8 2007 Planning and Layout M12 Circular The use of M12 circular connectors is not yet a defined standard although the M12 Connectors circular connector is used at the field bus level in many heavy duty industrial applications Schneider Electric recommends the M12 4 4 poles with D coding for Transparent Ready Industrial Ethernet networks in heavy industrial environments M12 Circular Connector Pins and Ethernet Signals gt Q O 0o 0 O male connector female connector For Ethernet 10Base T and 100Base TX the M12 circular connector pins have t
74. A CSU DSU Circuits so Switched PVCs ISDN Dynamic backup configuration for critical plant CSU DSU CTA Modem Remote Plant D The main plant is connected to the remote plants C and D by a packet switched frame relay connection using virtual circuits PVCs in this case The main plant is connected to remote plant A by ISDN lines There is one critical site Remote Plant D that is also connected with a circuit switched ISDN connection acting as a backup to the frame relay link This IDSN connection is dynamically configured on the high end router to connect only if the frame relay connection fails A dial up access server is also depicted top left it supports network management troubleshooting from remote locations in case all WAN connectivity to the main site is lost Other WAN specific hardware includes routers modems CSU DSUs at Remote Plants A B C and D and an ISDN terminal adapter at Remote Plant D 66 31006929 8 2007 Planning and Layout 2 3 Environmental Requirements At a Glance Overview A Transparent Ready industrial Ethernet network supports the connection of industrial automation devices with Ethernet connectivity PLCs I O sensors actuators etc and industrial Ethernet infrastructure devices cables connectors switches hubs etc Schneider Electric proposes three environmental categories e office e light industrial e heavy industrial This sectio
75. Access points have a setting of broadcast SSID If this is set to on the network name is broadcast and it appears as a choice to computers trying to connect Disable the broadcast This requires all computers to be pre configured with the SSID in order to connect to the network Most wireless networks use a DCHP server to assign IP addresses to clients Configure the server to give IP addresses to specific Modbus Plus addresses Do not configure any additional spare addresses Limit access to known MAC addresses Access points can be set up to allow only known IP and MAC addresses to connect The MAC address on most PCs especially laptops can be changed to match one existing on the network 31006929 8 2007 151 Planning and Layout WEP VPN and Firewalls Wired equivalent privacy WEP secures the network by encrypting data transmitted over radio waves so that anyone who wishes cannot simply listen to it WEP should be turned on Choose a WEP key which allows you to listen to the network Always generate a random WEP key never use a key based on a word The algorithms for generating keys from a word are known and programs exist to decipher word based WEP keys Therefore a word based WEP key is not secure it can take from only 3 hours up to a few days to crack The combination of VPN and firewalls is the best security solution but it is costly in terms of management time Run a VPN client on the laptops and a VPN endpoint
76. CPU scan the request arrives Time Client Server Syn _ Scan Syn Ack Request he a ee Scan Request Scan If requests are in the queue when a new request arrives the new request is placed at the end of the queue The new request is answered when it moves to the top of the queue The response time can be calculated as the number of requests in the queue divided by the number of requests that can be answered per CPU scan multiplied by the CPU scan time v Note Each method has its own queue Decide in which queue the new request is placed and perform the calculations based on the number of requests in the queue Several milliseconds should be added to the above times to accommodate any overhead This is much less than the CPU scan time and does not significantly affect the overall result 31006929 8 2007 323 Services Overview Response Times for Devices Product Best Case Average Worst Case Premium 1 2 ms 0 5 CPU 1 CPU scan scan Momentum 1 2 ms 0 5 CPU 1 CPU scan or 2 CPU scans if scan initial request opens a TCP socket Client device must be able to complete socket opening within 1 CPU scan for this to be accurate Quantum NOE or embedded port 1 2 ms 0 5 CPU 1 CPU scan no overload in number of scan requests therefore no requests in the queue Quantum NOE read write re
77. ConneXium Ethernet Switch 499NES25100 5 Port 10 100 Base TX 31005153 Quick Reference Guide ConneXium Ethernet Switch 499NES18100 8 Port 10 100 Base TX 31005416 Quick Reference Guide ConneXium Ethernet Cabling System Switch Management Manual 31005844 English 31005845 Fran ais 31005846 Deutsch 31005847 Espa ol ConneXium Ethernet Cabling System Quick Reference Guide 31005848 English Electrical Switch 10 100 Mbps 7TX 499NES17100 Optical Switch 31005849 Fran ais 10 100 Mbps 5TX 2FX 499NOS17100 31005850 Deutsch 31005851 Espa ol 499NTR10100 ConneXium Transceiver Quick Reference Guide Modicon Quantum Ethernet TCP IP Module User Guide 840 USE 107 Modicon Quantum Ethernet Web Embedded Server User Guide 840 USE 115 Quantum 140 NOE 771 xx Ethernet Modules User Guide 840 USE 116 140NOE771xx 140NWM10000 140CPU651x0 Unity Pro 2 0 User Guide FactoryCast User s Guide For Quantum Premium and Micro 31001229 FactoryCast HMI Premium and Quantum HMI Modules Setup 35007415 Manual Momentum 170ENT11001 170ENT11000 Ethernet Communication 870 USE 114 Adapter User Guide 174 CEV 200 30 Modicon TSX Momentum Modbus Plus to Ethernet 890 USE 151 Bridge User Guide 174 CEV 300 20 Mododbus to Ethernet Bridge User Guide 890 USE 195 12 31006929 8 2007 About the Book Title of Documentation Reference Number Advantys STB Ethernet Modbus TCP IP Network Interace 890 USE 177 Applications Guide TSX Micro TSX ETZ
78. Connection 501 Cable Shielding Connection Options 507 Copper Ethernet Testing Procedures 509 Performance Parameters 510 Definitions of Performance Parameters 512 31006929 8 2007 499 Earthing Grounding Procedures Well made Earthing Ground Connections Introduction When you connect metal structures and equipment to an earthing system the quality of the earthing connections is critical in protecting your equipment and achieving EMC Earth connections use conductive straps bars bolts and cable fasteners to interconnect the metal components of machines equipment cabinets cables shields and other conductive objects to your earthing system Type and Length When choosing the type of connection frame earth connections must be as short of Connections and wide as possible in every case f Note Make sure that connections are properly made and that all exposed metal components are properly grounded A well made connection has the LF and HF conductive properties you require and promotes a long service life for your equipment 500 31006929 8 2007 Earthing Grounding Procedures Making an Earthing Connection Introduction You can make two types of earthing connection e between two metal surfaces e between shielded cable and a metal surface Making a Make sure that earth plane plates are not coated with paint or any other type of Connection insulating covering Thes
79. Device Implementation The Modbus messaging service handles the transfer of data or commands between two devices One device is the client and the other is the server The client initiates the request and the server responds to the request These services use the Modbus protocol or Modbus over TCP IP in Ethernet applications to support the data transfer between devices POWER METER POWER METER POWER METER mo T Vai Tm Ti Tm zi Di i ii zi pa it eo ee eo 1 SCADA and HMI data requests 2 PLC data transfer 3 device data gathering Modbus has been the industrial communication standard since 1979 It is now combined with Ethernet TCP IP to support Transparent Ready solutions Modbus over TCP IP is a completely open Ethernet protocol The development of a connection to Modbus TCP IP requires no proprietary component or license purchase The protocol may be easily combined with any device that supports a standard TCP IP communication stack Specifications can be obtained free of charge from www modbus org The Modbus application layer is very simple and universally recognized Thousands of manufacturers are already implementing this protocol Many have already developed Modbus TCP IP connections and many products are currently available The simplicity of Modbus TCP IP enables any small field device such as an I O module to communicate over Ethernet without a powerful microprocessor or a large amount
80. Ethernet Module 250 200 4 32 devices 150 4 1004 50 4 A 8 devices ee 0 50 100 150 200 PLC Scan Time ms The curves above show that the response times for all devices remain within 5 to 6 ms of each other for 1 8 16 and 32 devices The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Local Output ms 140CPU43412A v2 0 10 ms 20 ms 50 ms 100 ms 200 ms NOE771x1 v3 5 Scan Scan Scan Scan Scan 1 device 16 29 61 124 231 8 devices 17 31 62 126 232 16 devices 19 33 64 127 234 32 devices 21 35 67 130 237 31006929 8 2007 399 I O Scanner Performance 400 31006929 8 2007 Modbus Server Throughput Capacity At a Glance Overview What s in this Chapter This appendix illustrates Modbus server throughput for Premium and Quantum systems that use industrial Ethernet This chapter contains the following topics Topic Page Quantum Modbus Server Throughput Capacity Unity v2 0 402 Premium Modbus Server Throughput Capacity Unity v2 0 404 31006929 8 2007 401 Modbus Server Performance Quantum Modbus Server Throughput Capacity Unity v2 0 Performance Measurements The following chart shows the number of Modbus read register requests that may be answered by Quantum CPUs in 1 s A read register request is a Mo
81. Field Input to PLC Memory The I O scanner system operates differently in the Quantum and the Premium see p 166 PLC systems Calculation of the system response time for either system depends on several factors and results in a complicated formula The formula is provided for reference but you should refer to the graphs in the appendix for most systems see p 373 These graphs provide the I O scanner system response times from e field input to the PLC memory e PLC memory to a field output e field input to the PLC through a decision and back to a field output Note For the following calculations the I O scanner repetition rate must be set to 0 ms Tnet is 0 05 ms at 10 MB and 0 005 ms at 100 MB For more accurate results the actual network transfer time can be calculated using the number of bytes sent the network traffic the network speed and the switch latency Tios is the number of entries in the I O scanner table x 0 3 ms For a Quantum NOE system the response time from a field input to the information in the PLC is given by the following two formulae time max Tmod Tios Tnet 2 CPU scans time average Tmod Tios x 0 5 Tnet 1 5 CPU scans For a Premium PLC system or a Quantum embedded Ethernet port system the response time from a field input to the information in the PLC is given by the following two formulae time max Tmod Tios Tnet 1 CPU scan time average Tmod Tios x 0 5
82. I O network If one controller fails the other assumes control of the I O system HTML hypertext markup language The code used to write web pages HTTP hyper text transfer protocol Protocol used to transmit files on the World Wide Web hub The center of a star topology network or cabling system A multi node network topology that has a central multiplexer with many nodes feeding into and through it The other nodes do not usually interconnect directly LAN hubs are becoming increasingly popular with the growth of twisted pair and fiber optics and with the need for LAN management 31006929 8 2007 525 Glossary hysteresis Until a plus or minus threshold around the value of a variable is exceeded a signal to notify other systems of a change of state is suppressed l 1 0 input output The transfer of date to and from a computer ICMP Internet control message protocol This extension of the IP protocol is used to test a connection on the Internet with the ping command It supports data packets with error control and information messages IEC International Electrotechnical Commission in Geneva IEEE 802 3 An Institute of Electrical and Electronic Engineers standard that defines the CSMA CD media access method and the physical and data link layer specifications of a local area network Among others it includes 10BASE2 10Base5 10Base FL and 10Base T Ethernet implementations IGMP Internet group management protocol This is
83. I O module that contains the input event should be linked to the fast task the fast task s first actions should be to check the I O module for the input and to time stamp that input if it represents a recordable event alarmi aut alarm2 2005 01 15 09 28 52 858 alarm3 2005 01 15 09 32 16 390 1 comparison of event times across the plant to determine the order of events 2 local time stamping of events 31006929 8 2007 213 Services Overview Action The time synchronization service can synchronize the activation of events across Synchronization one or more plants Use the fast task to make sure that the current time is set equal to the time at which the event is configured to occur If the time is correct then the output should be activated Accuracy is affected by the frequency of the fast task the length of execution of the fast task since the output is not activated until the fast task has completed and the I O activation time The I O module containing the event output must be linked to the fast task 1 synchronized actions across the plant 214 31006929 8 2007 Services Overview Comparison with Traditional Event Recording Systems The main differences between the time synchronization service and a traditional recorder system for sequence of events recording are cost and accuracy A traditional implementation has an accuracy of 1 ms but comes at a higher cost than a PLC system imp
84. J D The global data service has the following communication limitations e Adistribution group may contain up to 64 members each device that is a member can be a publisher subscriber or both e The current restriction is that each Ethernet module can be a member of only one group Therefore in order for a system to be a member of multiple groups there must be multiple Ethernet communications modules in that system e A publisher can publish a single block of data up to 512 words long e A subscriber can receive any number of published data blocks from the group although some PLCs restrict the total amount of data received by the service 200 31006929 8 2007 Services Overview When to Use Global Data Global Data Devices Global data is used when a single device wants to make the information it contains available to multiple devices within 10 ms to 30 s This service is used for publishing device data and plant status from one device to many others Global data is not recommended for issuing commands because the publisher does not send the data to an individual device and data transfer is not acknowledged The system is designed for a device to publish its status and for other devices to react to that status For example a drive publishes its speed and all other drives in the system adapt their speeds to match it The following devices implement global data with a maximum publishing of 512 words and a maxi
85. Modbus Client Response Times Premium TSXP57304M 413 Modbus Client Response Times Quantum 140 CPU65150 with an Embedded 420 Ethernet Port Modbus Client Response Times Quantum 140 CPU65150 with a 140 425 NOE77101 Ethernet Communications Module Modbus Client Response Times Quantum 140 CPU65150 with a 140 430 NOE77111 Ethernet Communications Module Modbus Client Response Times Quantum 140 CPU43412A with a 140 435 NOE77101 Ethernet Communications Module Modbus Client Response Times Quantum 140 CPU43412A with a 140 440 NOE77111 Ethernet Communications Module 31006929 8 2007 405 Modbus Client Performance Modbus Client Response Times Premium TSXP575634M Test Setup The following charts show Premium CPU response times where a client request block is triggered in PLC logic by reading data from a Modbus server The graphs represent the number of CPU cycles required for the PLC to complete all triggered Modbus client requests In all cases the CPU is a Premium TSXP575634M with an TSXETY5103 Ethernet communications module exec v3 10 The CPU logic scan times vary Modbus client response times are tracked with respect to six Modbus server response times lt 1ms 10 ms 20 ms 50 ms 70 ms e 100 ms 406 31006929 8 2007 Modbus Client Performance at a CPU Scan Time of 200 ms 12 CPU Cycles o 5 10 15 20 25 30 35 40 45 50
86. Monitoring can reduce network traffic and load on other devices but controlling communications in this way may not always be possible If both interfaces need to be active for global data for instance both interfaces process exchanges and pass the results to the device application the application must decide which information to use Here is a Premium PLC with two Ethernet ETY communications modules ty 2 LY 1 Interface 1 has its own IP address and appears as an independent device on the network 2 Interface 2 also has its own IP address and appears as an independent device on the network In systems like the one shown above you may be unable to control how communications are issued from each device because you cannot control which interface is used This is a common problem for PCs configured with two Ethernet cards The PC chooses a card to send data to based on the network on which the card is connected as defined by the IP address and the subnet mask The PC attempts to send requests through the card connected directly to the destination network If a PC is configured with two Ethernet interfaces that have different IP addresses on the same network the PC does not know which card to use As a result communications are erratic and can fail To avoid this problem configure each Ethernet card for a separate network address range and manually control communications by addressing the communications to one network or the other
87. Planning and Layout Mesh Topology A mesh topology is used in very large networks or network backbones where every end device or infrastructure device has a connection to one or more components of the network Ideally each device is directly connected to every other device in the mesh Another mesh implementation is as a network backbone that connects separate star structures This combined topology provides fault tolerance to the backbone without the high cost of a mesh topology throughout the entire network Star Mesh topologies are used less frequently because of cost and complexity Advantages Disadvantages Fault tolerance if a break occurs anywhere in the network cable segment traffic can be rerouted Complexity difficult to manage and administer High cost more cabling and interfaces are needed to support the redundant connections 48 31006929 8 2007 Planning and Layout Developing Network Architecture for Industrial Ethernet Networks Introduction Along with a basic understanding of network architecture topologies and Ethernet for office environments there are some further considerations when deploying Ethernet in a plant environment The various topologies and their application in an automation plant layout are discussed with suggestions for appropriate hardware Ethernet Bus An Ethernet bus can be deployed by interconnecting hubs and o
88. SCADA system must be able to receive the data transfer through a Modbus messaging server Exception reporting is used for reporting the status of field devices for display trending and alarms Exception reporting is efficient because the same unchanged values are not transferred over and over again as they are in a polled system This exception reporting system allows the device to close the TCP socket when data values are unchanged thereby freeing up the TCP socket for other uses and reducing the device load SCADA systems normally poll data from field devices to monitor the status of each device The SCADA can detect and notify you of a communications failure If the SCADA system is not polling the field device as in an exception report system it cannot detect or report a communications failure To enable the SCADA system to detect a communications failure it must either e expect write commands from the field device every n seconds e poll the field device occasionally to check if it is on line An additional problem is that a write response from the field device can be lost or a value can change while the SCADA system is unable to receive the message In this case the SCADA system displays the old value but does not display a communications error To correct this the field device periodically transfers the tag value 31006929 8 2007 277 Services Overview Field Device Monitoring Variation on Exception Repo
89. Server SNMP X xX X X X FTP Server X X X X X TFTP Server X X X X X Telnet Server x x x x x 1 For factory diagnostic purposes only Premium Ethernet Communications Modules The following table lists the Ethernet services supported by the Premium Ethernet communications modules Service TSXETY4103 TSXETY110WS TSXETY5103 TSXWMY100 I O Scanner X xX Modbus Server X xX X X Modbus Client xX xX X X Global Data X xX FDR Server Xx xX FDR Client BootP Client xX xX X X Time Synchronization xX E mail Notification X xX X Web Embedded X X X X Diagnostics FactoryCast Web Server X xX X FactoryCast HMI Web X Server SNMP X X xX X FTP Server xX x xX X TFTP Server xX X Telnet Server x x2 x2 x 1 For factory diagnostic purposes only 31006929 8 2007 313 Services Overview TSX Micro Ethernet Communications Modules Momentum M1E Processors The following table lists the Ethernet services supported by the TSX Micro Ethernet communications modules Service TSXETZ410 TSXETZ510 V O Scanner Modbus Server Modbus Client X X X X Global Data FDR Server FDR Client x lt BootP Client x Xx x lt Time Synchronization E mail Notification Web Embedded Diagnostics x lt FactoryCast Web Server
90. Thinner more flexible and light weight Optical fiber can be drawn thinner than copper wire making it lighter more flexible and easier to position through small spaces e Low power Optical fiber signals degrade less and therefore require lower power transmitters to boost signals e No disturbance or other risks Because no electricity passes through optical fibers there is no electromagnetic interference and no fire or earthing hazard 31006929 8 2007 85 Planning and Layout 10 100BaseF Physical Layer Specification Introduction 10Base FL Cable Specification 100Base FX Cable Specification Schneider Optical Fiber Recommen dations 10 100BaseF refers to specific physical layer specifications for fiber optic cable carrying Ethernet signals The traditional Ethernet 10Mb s includes specifications for the 10Base FL physical layer 10Base FL supports fiber optic cable backbones of up to 4 km The TIA EIA Commercial Building Wiring standard approves 10Base FL for cross connections between campus buildings The 10Base FL has a transmission rate of 10Mb s 20Mb s in optional full duplex mode and the maximum segment length is 2000 m The typical cable is multi mode fiber 62 5 125 62 5 um fiber core with 125 um outer cladding 850 nm wavelength The 100Base FX physical layer specification is approved by the IEEE 802 3u standard for Fast Ethernet 100 Mb s over fiber optic cable The 100Base FL has a tr
91. Tnet 0 5 CPU scans 31006929 8 2007 329 Services Overview Response Time Formulae Field Input to Decision to Field Output Response Time Formulae Decision to Field Output For a Quantum PLC the response time from a field input to a decision in a field output is time max Tmod Tios Tnet 3 CPU scans Tios Tnet Tmod time average Tmod Tios x 0 5 Tnet 2 5 CPU scans Tios x 0 5 Tnet Tmod For a Premium PLC the response time from a field input to a decision in a field output is time max Tmod Tios Tnet 3 CPU scans Tios Tnet Tmod For a Quantum PLC the response time from a decision to a field output is time max 1 CPU scan Tios Tnet Tmod time average 0 5 CPU scans Tios Tnet Tmod For a Premium PLC the response time from a decision to a field output is time max 2 CPU scans Tios Tnet Tmod time average 1 CPU scan Tios Tnet Tmod 330 31006929 8 2007 Services Overview Total Load on Devices Summary device does not exceed the following limits Be sure that the total number of Ethernet messages being sent to and from the Processing Capacity of Ethernet Connections Premium Ethernet TCP IP Quantum Ethernet TCP IP TSXETY110 TSXETY4103 TSXP575xx 140NOE771 140CPU65150 TSXETY210 TSXETY5103 140NWM10000 5 140CPU65160 TSXETY110WS TSXWMY100 5 140CPU67160 T
92. Troubleshooting 345 4 3 Services Troubleshooting 354 4 4 SCADA HMI System Slow Response Time Troubleshooting 364 4 5 Bridge Troubleshooting 365 4 6 Lost Packet Troubleshooting 366 31006929 8 2007 341 Troubleshooting 4 1 About Troubleshooting At a Glance Introduction This section introduces troubleshooting for Transparent Ready networks What s in this This section contains the following topics Section z Topic Page Introduction to Troubleshooting 343 General Problem Identification 344 342 31006929 8 2007 Troubleshooting Introduction to Troubleshooting Overview The troubleshooting tables in this section cover the issues you are most likely to encounter with a Transparent Ready network Owing to the complexity of network design it is impossible to account for every type or problem that can occur Here are some questions to ask yourself that cover the most common problems encountered e Is the device powered up e Are cables properly connected e ls the IP address correct To avoid redundancy this manual explains the issues above in the network tables see p 345 and not for every service Modbus I O scanner etc to which they can potentially apply This manual is not able to anticipate defects and lockups for all devices on the market so there are few instances in which Schneider recommends a power recycle for a network device To achieve qu
93. United States TIA EIA 568 B Telecommunications Industry Association Electronic Industries Commercial Building Telecommunication Cabling standard defines how to design build and manage a structured wiring Normalisation Electrotechnique Association system International ISO IEC 11801 International Organization Generic Customer Premises Cabling for Standardization standard defines general cabling International Engineering specifications for customer premises based Consortium on TIA EIA 568 Europe CENELEC EN 50173 Comit Europ en de Defines generic cabling and European open market cabling components based on ISO 11801 32 31006929 8 2007 Planning and Layout Environmental Standards Environmental standards are not specifically related to industrial Ethernet but apply to any device or equipment located in the particular environment Schneider Electric has defined three types of environments that coincide with the MICE table e office environment where standard Ethernet can be used e light industrial environment e heavy industrial environment The environmental requirements for industrial Ethernet are defined by the same specifications that cover other industrial automation devices see p 67 31006929 8 2007 33 Planning and Layout 2 2 Physical Planning and Layout At A Glance Overview This section p
94. VijeoLook 2 6 includes the correct version of OFS 31006929 8 2007 267 Services Overview Build time Runtime Architecture for Unity OFS SCADA Systems that Are Not Frequently Modified Sample Architecture Build time Runtime Option The following example of a build time runtime system supports architectures that e do not require frequent modifications of the application e have a low constraint on synchronization between the SCADA and the running application during modifications The synchronization between the Unity Pro database and OFS is managed manually there is static exchange of the symbols file SCADA XVM files Unity Pro Symbols for OFS Synchronization by static exchange ann a With VijeoLook as the SCADA a maximum of 5 PLCs can be supported For larger configurations use Monitor Pro One PC is used to run both the SCADA and OFS software Another PC is used to run Unity Pro on the PLC applications On Ethernet TCP IP only you may locate the XVM symbols file on a different PC than the one that runs the SCADA and OFS This option lets you centralize the resources on one PC that can be easily backed up This implementation may be necessary when the system is integrated in a larger architecture 268 31006929 8 2007 Services Overview Key System Characteristics Product Versions The runtim
95. a common bonding network that consists of multiple conductive elements 94 31006929 8 2007 Planning and Layout Equipotential Bonding Introduction Earthing System Components Equipotential bonding creates an interconnection of conductive parts that disperses the flow of EMI disturbances over multiple paths connecting to the earth through an earthing system The design of an earthing system is determined by local conditions and requirements The layout of your building and of all the machinery within it determines how simple or complex your earthing system needs to be The topics that follow describe at a high level what you can do to create equipotential bonding and earthing systems at your site so that it can be protected against EMI disturbance For more details see p 489 The typical earthing system consists of three components e actual earth which conducts current into the ground through an earth electrode a pipe or a metal conductor e earthing main conductor a conductive system to which the earth and all necessary parts of the installation are connected e earthing conductors which connect parts of the installation to the earthing main conductor 31006929 8 2007 95 Planning and Layout Equipotentially Bonding Your Building Introduction Terminology The EN 50310 standard requires buildings with telecommunications systems to be fitted with a common bonding network CBN that cons
96. a network manager network Administrative services for managing a network including configuring and tuning management maintaining network operation monitoring network performance and diagnosing network problems NFS network file system A protocol for file sharing among UNIX hosts NIC network interface card An adapter card inserted into a computer that contains the necessary software and electronics to enable the station to communicate over the network NMS network management system A manager within SNTP that can query and get responses from agents and set variables in them node Any intelligent device connected to the network including terminal servers host computers and devices such as printers and terminals that connect directly to the network A node can be thought of as any device that has a hardware address NTP network time protocol A protocol in TCP used to synchronize time on devices across a network uses signals from atomic and radio clocks O OEM original equipment manufacturer Buys computers in bulk customizes them for a certain application and resells them under its own name OLE object linking and embedding Microsoft software system that lets Windows applications move and share information OPC Specification for process control and manufacturing automation defines standards for objects methods and interfaces 530 31006929 8 2007 Glossary osi OSI reference model OSPF open
97. a structured hierarchical star topology network in which high speed fiber optic cables feed slower peripheral networks The standard was incorporated into TIA EIA 568 B in 2000 Standard Focus Description TIA EIA 568 A 1995 Commercial building telecommunications Wiring standards Defines a standard for building cable systems for commercial buildings that support data networks voice and video It also defines technical and performance criteria for cabling TIA EIA 568 A 1998 1999 Updates A1 outlines propagation delay and delay skew parameters A2 specifies miscellaneous changes A3 defines requirements for bundled and hybrid cables A4 defines NEXT and return loss requirements for patch cables A5 defines performance requirements for Enhanced Category 5 CAT5e TIA EIA 568 B 1 2000 Commercial building telecommunications Wiring standards Incorporates previous updates into a new release and specifies Category 5e cable as preferred due to its performance Several addenda specify technical information for 100 Q twisted pair cable shielded twisted pair cable and optical fiber cable ANSI TIA EIA 568 B 2 100 twisted pair cabling standard ANSI TIA EIA 568 B 3 Optical fiber standard TIA EIA 569 A 1995 Commercial building standard for telecommunications pathways and spaces Specifies how to build pathways and spaces for telecommunication media TIA EIA 606 1994 Buildi
98. an Ethernet packet capture device to detect this problem 31006929 8 2007 357 Troubleshooting SNMP Troubleshooting Device Discovery Topic Issue A device cannot A known network device can not be discovered by an SNMP management be discovered system usually because the device does not support SNMP or because a firewall blocks SNMP traffic Check the network device with a ping request from a DOS prompt If the ping is successful the error is probably in the network management package An unsuccessful ping indicates a likely problem with the device itself See Network Troubleshooting see p 345 Data Access Topic Issue A device can be incorrect community strings the read string must be correct to discovered but read data and the write string must be correct to write data cannot be accessed different versions of SNMP V1 V2 V3 for details on versions to read data refer to SNMP sections of networking see p 244 358 31006929 8 2007 Troubleshooting Telnet and FTP Troubleshooting Device Access Incorrect Login or Restricted Access These tables describe troubleshooting for Telnet see p 247 and FTP see p 256 issues Topic Problem Solution Cannot A firewall is a An error message on the client side can sometimes detect this access common access problem but in a more ideal situation device restriction
99. and cost effective to set up thin client terminal e an HMI application that is easy to maintain because it resides in a single location on the server e preventive maintenance notification via email e data archiving directly from the data source FactoryCast HMI supplements conventional SCADA systems SCADA Vijeo Look or Monitor Pro software provides a means of centralizing information in order to perform global supervision from a central site Combining a FactoryCast HMI solution and a conventional SCADA solution enables e simplification of the SCADA application by locating some of the SCADA processing at the source level e increased availability to trace data due to the direct connection between FactoryCast HMI modules and relational databases e powerful ready to use remote diagnostics 238 31006929 8 2007 Services Overview Direct Links and Information Management Levels The HMI Tag Database Web Service Characteristics In hybrid architectures FactoryCast HMI eliminates the need for intermediate devices gateways which are expensive to install and maintain It establishes a direct link between the automation levels and the global information management levels MES ERP etc The PLC archives information directly from the automation system in relational databases allowing a collaborative automation system to share data in real time This solution results in e simplified architectures e lower ins
100. application is not blocked during the time it takes to obtain the data The activated notification mechanism then announces the results to the client Synchronization with the PLC is the same as the process outlined for synchronous services OPC Client OFS EXE Application Code Interface OPC Server Asynchronous READ WRIT OPC read write Event Data Ready Back to Application Wait Data Code Callback proc Data available Update Data Back to Application Data R Code Request DEVICE OFS performs read polling and notification of changes in variable values The client application needs a wake up function programmed into it The OFS should call the wake up when the values of items in periodically examined groups change The wake up function must be unique in the client application It receives all the notifications from the OFS then it redistributes them to the processing functions specific to each periodically scanned group Note For ready to run supervisory software the wake up function should be pre programmed If this is not the case do not use the notification mechanism The OPC standard OnDataChange sets the name of this wake up function The OFS notifies by group not by individual items For a given group the OFS sends the client application wake up function a list of items whose value has changed In the case of a table type item the OFS transmits the whole table even if only a
101. bonding network that is the principal means for effecting earthing inside the building Note Design and create a fine meshed earth plane in areas where sensitive hardware such as data processing and measuring equipment will be stored or used 31006929 8 2007 97 Planning and Layout Local Equipotential Bonding of Equipment and Machines Introduction Connecting Cabinets to a Local Earthing System After creating an equipotential bond for the building see p 96 you can create local low frequency LF and high frequency HF equipotential bonding of equipment and machines Step Action Considerations 1 Systematically interconnect all the metal structures of single equipment items to create local earthing systems earth frames Everything from cabinets and the earth plane plate beneath them to cable troughs pipes and metal frames of the machines must be interconnected 2 If necessary add earth conductors for Make sure that the used and unused interconnections between exposed ends of any cable conductor are conductive parts connected to the earthing system 3 Connect the local frame earthing system to the earthing system of the site by providing the maximum number of distributed connections Make sure that there is an earth plane plate at the bottom of every cabinet All the exposed metal parts of components and units fitted in a cabinet must be bo
102. by the requesting device the delay from the time the requesting device sends the request to the time the gateway receives the request is dependent on the source network For an Ethernet network the delay is normally 0 05 ms For a Modbus Plus network the delay may be up to one token rotation time 31006929 8 2007 337 Services Overview Calculation of Serial Line Transmission Time Calculation of the Number of Supported Devices per Bridge In steps that have a delay the system response time is the total of all the delays The delay for transferring the request and the response across the network may be different For example a serial network takes much longer to transfer a response including 100 registers of data than it does to transfer the request itself contains no actual data Two items complicate the calculation of the system response time e a queue of messages in the gateway due to time outs or multiple queries e the time out of a message on the destination network this is applicable in a network that must hold all future messages until the current message has timed out e g Modbus serial line To improve the system response time limit the number of requests being sent through the gateway by limiting the number of devices connected to each gateway The serial line response time is determined by the number of bits sent and the serial line speed Refer to the Modbus protocol specification for the exact
103. cable planning 32 for Ethernet performance 32 for installing an Ethernet system 32 for selection of Ethernet equipment 32 international 29 structured cabling 32 standby monitoring using SCADA in a Quantum hot standby system 300 star topology 44 static pages in a Web server operation 226 storage temperature range requirements 71 554 31006929 8 2007 Index straight copper cable color code 105 pinout 105 strategy for Transparent Ready 18 stripper for building Ethernet copper cables 108 110 structured cabling standards 32 subscriber in a global data operation 199 switch in an Ethernet system 59 in an Ethernet WAN 65 switched networks and collision management 56 switched virtual circuits in an Ethernet system 64 synchronizing applications Transparent Ready services 157 synchronous services in an OPC factory server operation 261 system elements of Transparent Ready 24 system evaluation 165 T TCP in the Transparent Ready model 129 TCP socket limits for Modbus server services 195 TCP socket numbers in a Quantum hot standby system 303 TCP socket usage for I O scanning 173 TCP IP in the Transparent Ready model 128 TCP IP model based on OSI 125 Telnet 161 ConneXium device support 255 Momentum device support 253 Premium device support 252 Quantum device support 250 troubleshooting 359 Telnet service 247 tensile strength requirements 70 test data cabling
104. code A unique identifier made up of an IP address and a port number for an end point of communication in a system application synchronous optical network Signal standard in digital transmission STP A technique that detects loops in a network and logically blocks the redundant paths ensuring that only one route exists between any two LANs used in an IEEE 802 1d bridged network See rapid spanning tree An algorithm used by bridges to create a logical topology that connects all network segments and to ensure that only one path exists between any two stations A security attack in which an intruder sends a message using the stolen hacked IP address of an identified host on the network in order to gain unauthorized access structured query language Used to query request data from a relational database 536 31006929 8 2007 Glossary SSID star topology store and forward STP STU application file subnet supernetting switch switched Ethernet switched virtual LAN switching hubs SYN SYN ACK service set identifier A sequence of 32 letters or numbers in the packet header that uniquely identifies a wireless LAN A network where each workstation is connected to a central hub through a dedicated point to point connection Technique for examining incoming packets on an Ethernet switch or bridge whereby the whole packet is read before forwarding or filtering takes place Store and forward
105. controller data server that can deliver data to OPC clients and can communicate with Compact Micro Momentum Premium Quantum TSX Series 7 and TSX S1000 PLCs OFS provides the client applications with a group of services called methods for accessing control system variables OFS is a PLC data access OPC server that is compliant with OPC 1 0A and OPC 2 0 it functions with any OPC compliant client and with two types of OPC compliant software e supervisory software the OFS assumes the role of a driver by ensuring communication with all Transparent Ready devices e custom supervisory software using either the OLE automation interface or the OLE custom interface The following illustration shows an OFS interface I Pump I Client S H erver l OFSClient OFSDoc1 Group 1 OPC 2 0 l Fle View Server Group Item Test Tools Window Help I DeB I OFSDuel GRPI OPC 2 0 lox F MB_ETH_MEP11A_Base_Temperature Field Value T eee F Update ST 14 10 2004 10h27min394 a Ww Eaa Gest roma Bat OLE Ee feat O e e lal e lal iy m coe LL Gate ll i PLC 3 Micro PLC 1 Quantum PLC 2 Premium OFS provides the interface between Schneider Electric PLCs and one or more client applications in which some of the device data values are viewed and or modified 31006929 8 2007 257 Services Overview OFS Capabilities Data Exchange Mod
106. curves below illustrates Quantum PLC response times when a signal is Setup sent from a remote input module through the PLC to a remote output module b 7 Response Time The signal is triggered by a Momentum input module with a response time of 2 ms scanned into the Quantum PLC at a repetition rate of 0 ms see p 174 copied to another internal variable within the PLC written to a Momentum output module with a response time of 2 ms Results are plotted for 1 8 16 and 32 devices 388 31006929 8 2007 I O Scanner Performance 140CPU65150 The 140CPU65150 used for the following measurements is at version 2 0 with an with Embedded embedded Ethernet port at version 3 1 Ethernet Port 450 400 4 350 4 300 4 250 4 200 4 150 100 50 4 32 devices Time ms 8 devices 0 50 100 150 200 PLC Scan Time ms The bottom curve shows that the response times for 1 to 8 devices are within 1 to 3 ms of each other The response times for 16 devices are 2 to 4 ms longer initially as scan time increases the difference in response times becomes larger e g 11 ms at a 200 ms scan rate The response times for 32 devices are 13 to 17 ms longer initially as scan time increases the difference in response times becomes larger e g 34 ms more at a 200 ms scan The table below shows the data points used to generate the graph represented
107. device replacement FDR SNMP network administration bandwidth management NTP time synchronization notification of SMTP events via electronic mail optional TCP open At the transport layer UDP supports six services and TCP supports four services Transport Layer Application Layer Service Provided UDP SNMP MIB Network management NTP Time synchronization RTPS Global data transfer DHCP Faulty device replacement FDR TFTP TCP FTP HTTP Web server SMTP Email notification TCP Open Modbus Message handling Modbus I O scanning 31006929 8 2007 129 Planning and Layout IP Addresses and Classes Summary Dotted Decimal Notation Network Address Defined Classful Addressing An IP address allows a device to have a unique logical address to locate the device on the TCP IP network and group it with others for network design and management purposes A computer sees an IP address in a binary form of 32 bits For ease of use the 32 bits have been divided into four 8 bit groups Each group is converted into its decimal equivalent which results in four decimal numbers separated by dots As an example an IP address in binary 10001011 00101101 00100100 00001 100 can be written in a simpler format by converting each individual octet into a decimal value 139 45 36 12 10001011 00101101 00100100 00001100 139 45 36 12 An IP addre
108. electric fields Enables buzz low frequency disturbance to be avoided Shielding can cause resonance due to the antenna effect This means the disturbance is greater than when shielding is present Shielded Cable Ground Loops One of the risks of earthing cable shields at both ends is the creation of ground loops Ground loops occur when current circulates through the shield due to the different potential between the extreme ends of the shield If this happens you need to achieve the same potential at both ends If you are working with an existing installation consider laying a binding conductor in parallel to the network cable For very long distances use fiber optic cable 508 31006929 8 2007 Earthing Grounding Procedures Copper Ethernet Testing Procedures Introduction Copper Installation Testing Copper Performance Testing The following discussion describes verification of installations such as wiring and proper lengths and references specifications for the testing of performance defined in Chapter 7 of ISO IEC 11801 Make sure to test copper wiring for correct pin termination at each end continuity to the remote end short circuits between any two or more conductors crossed pairs split pairs reversed pairs shorted pairs other miswiring The ISO IEC 11801 standard requires that you test both channel and permanent links as follows e The performance of th
109. elements included in your implementation depend on the following size of the campus or building geography of the site purpose of the cabling system applications and equipment types of end user 31006929 8 2007 37 Planning and Layout Configuration It is possible to configure a generic cabling system to your specific needs by rearranging the distributors to support different topologies see p 43 such as bus star and ring The following diagram shows the linear connections of a cabling system from campus distributor to the terminal outlet and equipment NOOR WD Campus distributor Backbone cabling Building distributor Secondary cabling Floor distributor Tertiary cabling Telecommunication outlet 38 31006929 8 2007 Planning and Layout The next two diagrams show how a generic cabling system can be physically implemented in a single building or multiple buildings along a campus backbone Optional 2 Backbone cabling 4 Secondary cabling Backbone cabling Secondary cabling Tertiary cabling Patch cord Generic cabling system ownnRND 31006929 8 2007 39 Planning and Layout Cabling in a Transparent Ready Industrial Ethernet System Introduction Multiple Plant Site Example The Transparent Ready approach to planning a cabling system is similar to that of industrial Ethernet organizations such as Modbus IDA
110. error state or assume a fallback address You can distinguish this problem from the errors above only with a packet capture tool Use an Ethernet packet capture tool This is seen as the client not obtaining an IP address The client device may report an error code or go to the default IP address Configuration File Topic Problem IP address obtained but no configuration file for an FDR system unreachable machine A firewall in front of the FDR server may allow the DHCP request for an IP address but block the FTP TFPT request for the configuration file When a PC used as an FDR server the file server can be on a different 360 31006929 8 2007 Troubleshooting SMTP Troubleshooting Cannot Connect to Server Cannot Send Messages Messages Slow to Arrive These tables describe troubleshooting for SMTP issues see p 358 Topic Problem Solution Firewall Check that firewall allows SMTP traffic Password i Password Check that the server uses the same password scheme incorrect as the client Check that the passwords are correct Topic Issue Server failure Check server connection error counter Issue Solution Server Send e mail from PC client to confirm that it is a server delay and not a client delay delays If server delay is confirmed consult the IT staff 31006929 8 2007 361
111. fields of electro technology ISO International Standards www iso org Worldwide federation of national standards institutes Worldwide Organization from 146 countries Cabling standards is a very small part of the ISO s total responsibilities CENELEC Comit www cenelec org Develops electro technical standards for the European Europe Europ en de Normalisation Market European Economic Area Many CENELEC Electrotechnique cabling standards mirror ISO cabling standards with minor differences Canadian Standards www csa ca An association that works internationally to set Canada Association CSA standards for products and services through tests certification inspection for safety and performance including EMC and IEC testing IEEE 802 3 International www ieee org A working group that develops standards for CSMA Worldwide Electrical and Electronics CD Ethernet based LANs including 1000Base T and Engineers 100Base T ANSI www ansi org Facilitates development of the American National Worldwide Standards ANSI is the sole U S representative and dues paying member of the two major non treaty international standards organizations ISO and IEC via the U S National Committee USNC Through ANSI the U S has immediate access to the ISO and IEC standards development processes 480 31006929 8 2007 Standards and Considerations Standards Organization WebSite Description Area of Influence Internet Engine
112. for situations where a single request failure is experienced followed by a successful retry This section contains the following topics Topic Page EGX400 Gateway Serial Server Response Times 458 EGX400 Serial Server Response Measurements with One Request Timeout 463 31006929 8 2007 457 Gateway Performance EGX400 Gateway Serial Server Response Times Test Setup The following charts track the time it takes to get responses from a certain number of requests sent to devices connected on the serial side of the EGX400 gateway The performance is based on network baud rates of both 9600 and 19 200 and on the amount of data i e the number of registers requested The following legend describes the baud rate and number of requests sent as tracked in all four of the charts that follow Curve Number of Requests Baud Rate 1 16 9600 2 19 200 3 8 9600 4 19 200 5 1 9600 6 19 200 458 31006929 8 2007 Gateway Performance Serial Devices with 50 ms Response Time Time ms 7000 5 6000 4 5000 4 4000 4 3000 4 2000 4 1000 4 80 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 50 EGX200 Time to Complete All Requests Baud Rate 9600 19200 Number of
113. for which they are registered Gopher a network protocol for document search and retrieval which goes for information and uses a web of menu items like the holes of gophers to do so 524 31006929 8 2007 Glossary GPS global positioning system A system of satellites and receiving devices used to calculate position on Earth H half duplex Data transmission that can occur in two directions over a single line but in only one direction at a time hardware See network address address head end A central point or hub in broadband networks that receives signals on one set frequency band and retransmits them on another Every transmission from one workstation to another in a broadband network must go through the head end It enables a network to send and receive on the same cable header The control information added to the beginning of a transmitted message It contains essential information such as the packet or block address source destination message number length and routing instructions HMI human machine interface The screen of a device the design of which makes its use intuitive to the user host Generally a node on a network that can be used interactively i e logged into like a computer host table A list of TCP IP hosts on the network and their IP addresses HSBY hot standby system This system is based on two identically configured programmable logic controllers linked to each other and to the same remote
114. form the backbone for high availability applications Two Topology paths are available to reach the same device If ring topology is required switches that support either a proprietary ring topology or spanning tree protocol either spanning tree or rapid spanning tree need to be used Spanning tree protocol STP IEEE 802 1D or rapid spanning tree protocol RSTP IEEE 802 1w are protocols that avoid communication loops and find a new communication path when the initial one is no longer available The recovery time time to find a new path is about 30 s with STP With RSTP and proper network design recovery time could be as low as 100 ms Ce viii eea eera g TTT TT 2 31006929 8 2007 51 Planning and Layout Ethernet Mesh An Ethernet mesh network offers more redundancy than an Ethernet ring Topology architecture In a ring two paths are typically available to the same device Ina mesh network more than two paths are typically available To develop an Ethernet mesh topology switches that support spanning tree or rapid spanning tree protocol are required 52 31006929 8 2007 Planning and Layout Redundant Ring Topology Summary A redundant ring topology is recommended for automation environments where there is a critical need for a fault tolerant network Unlike a dual ring topology where there are two links on every device a redunda
115. from a PLC to the Internet is established any client connected to the Internet can access the PLC Remote clients can access Web pages implement diagnostics programming and perform many other functions 142 31006929 8 2007 Planning and Layout Comparison of Remote Access Options Method Accessible PLC Protocol Web Page Setup Ongoing Setup Client Systems Access Access Cost Cost Difficulty Requirements Direct Dial up Single PLC Yes No Low Phone Low Must run full PLC to Device charges SCADA software etc Remote All devices Yes Yes Low Phone or Low to Remote control Control of PC Internet high software must be via Dial up Charges installed on local and remote PC Note of caution in this case security may be compromised Remote All devices Yes Yes Medium Phoneor Low to PLC SCADA Access via on the local Internet high software Web RAS or VPN Ethernet Charges browser network PLC All devices Yes Yes Medium ISP costs High PLC SCADA Connected to have an High software Web the Internet Internet browser connection 31006929 8 2007 143 Planning and Layout Network Access Methods Summary The cost and the number of users you need to support are the determining factors when choosing a remote access method You should not deploy VPNs or any security technology without an associated policy see p 149 in place Be aware of the data on your
116. integration points between automation systems and business applications Using the device as a data server within a client server architecture allows Schneider alliances to develop interfaces to business systems in Windows or UNIX environments 3 Develop an open infrastructure that supports real time and deterministic behavior The network is the backbone for an efficient information exchange Ethernet TCP IP and Modbus are Schneider s primary choices for delivering an open network Switches and hubs help to build real time and highly available subnetworks and to address a broad range of applications 18 31006929 8 2007 Transparent Ready Transparent Ready Service Classes Offered Summary The Transparent Ready service classes make it possible to identify the services provided by each product e Diagnostic display and control services via Web technologies e Ethernet communication services Web Service Transparent Ready Web services are defined by 4 classes identified by letters Classes e Class A no Web services e Class B standard Web services e Class C configurable Web services e Class D active Web services Transparent Ready products with an embedded Web server can provide 4 types of Web service maintenance Web services control Web services diagnostic Web services optional Web services such as documentation or configuration 31006929 8 2007 19 Transparent Ready The following chart spec
117. is exceeded additional Modbus messaging requests are rejected and not sent an error is generated in the user logic For a Momentum system each Modbus messaging request requires that a TCP socket be opened before the request can be sent The Modbus TCP socket is closed at the completion of each request A Modbus client request response time is response time 1 CPU scan to send the open socket request server response time to the open socket 1 CPU scan to send the request Modbus server response time 1 CPU scan to receive the response back into the user logic If the maximum number of Modbus client requests is exceeded additional Modbus messaging requests are rejected and not sent an error is generated in the user logic 31006929 8 2007 327 Services Overview Modbus Client Communication Limits Product Number of TCP Socket Usage Multiple Requests Requests per Socket Quantum NOE 16 One per remote device yes Quantum embedded 64 One per remote device yes Ethernet port Premium TSXP571xx 16 One per remote device yes Premium TSXP572xx 32 One per remote device yes Premium TSXP573xx 48 One per remote device yes Premium TSXP574xx 64 One per remote device yes Premium TSXP575xx 80 One per remote device yes Momentum 16 One per Modbus no messaging request 328 31006929 8 2007 Services Overview I O Scanner Systems Overview Response Time Formulae
118. maintenance functions They can be run either locally or remotely through a simple Internet browser This service uses an embedded Web server and a real time data server All data is presented in HTML format and can be accessed from any Internet browser This service is a convenient way to monitor the health of devices on the network and to access operational and configuration information The embedded Web server is a real time PLC data server All the device diagnostic and configuration data is viewed in HTML by using any Internet browser with a Java virtual machine JVM to support the integrated Java code No programming is required at either the Transparent Ready device level or at the PC running the Web browser 224 31006929 8 2007 Services Overview Web Service and Some automation devices allow remote configuration via Web pages For example Web Pages Altivar drives provide access to current speed information and allow you to configure acceleration rates through the Altivar drive s Web pages The Web client can then access the Altivar drive s Web pages Web client Altivar drive Another application is monitoring power usage in apartment buildings If Power Logic circuit monitors are installed at various circuit breakers throughout the building an administrator can remotely monitor the power usage of each tenant simply by accessing the Power Logic circuit monitor s Web page with a Web browser Eliminating the
119. measure the number of router hops or routes between systems to help locate problems Type tracert exe at the command prompt A network device capable of both transmitting and receiving messages It serves as the interface between a user device and a network so that it may actively convert signals between the network and the local node Cable that attaches a device either to a standard or thin coax Ethernet segment Schneider solutions for optimizing electrical distribution industrial control and automation performance twisted pair Inexpensive multiple conductor cable comprising one or more pairs of 18 to cable 24 AWG copper strands The strands are twisted to improve protection against electromagnetic and radio frequency interference The cable which may be either shielded or unshielded is used in low speed communications as telephone cable It is used only in base band networks because of its narrow bandwidth U UDP universal datagram protocol A transport layer protocol for datagrams used primarily for broadcasting Also responsible for port addresses UL approval Tested and approved by Underwriters Laboratories Inc 31006929 8 2007 539 Glossary UL cable certification UMAS protocol In conjunction with several manufacturers UL has developed a data transmissions performance level marking program This approval is printed on a cable as shown below Level performance is intended for basic communicati
120. model specifies how dissimilar computing devices such as NICs bridges and routers exchange data over a network The model consists of 7 layers From lowest to highest they are physical data link network transport session presentation and application Each layer performs services for the layer above it ISP Internet service provider J jabber Network error caused by an interface card placing corrupted data on the network Also an error condition caused by an Ethernet node transmitting longer packets than allowed JVM Java virtual machine Executes compiled Java code sits on top of the operating system L LAN local area network A data communications system consisting of a group of interconnected computers sharing applications data and peripherals The geographical area is usually a building or group of buildings LAN Dividing local area network bandwidth into multiple independent LANs to improve segmentation performance latency With respect to Ethernet the delay incurred by a switching or bridging device between receiving the frame and forwarding the frame layer With respect to networks the software protocol levels that comprise the network s architecture where each layer performs functions for the layer s above it line speed The maximum rate at which data can be transmitted reliably over a line using given hardware expressed in bit s 31006929 8 2007 527 Glossary link Physical connection betwee
121. most suitable Transparent Ready service is the display of diagnostic and customized Web pages see p 223 Modbus and or other industrial fieldbus protocols are used to control field devices 31006929 8 2007 157 Services Overview Communication Service Selection Summary The following description of services and the services tables that follow in the next discussion can help you decide which services are best for your application I O Scanning The I O scanning service allows you to exchange information repetitively between one central device and many remote devices without the need for special programming in either device It is used when you want to exchange data repetitively and at a fast rate every 1 ms to 5 s A typical example of a device that can use the I O scanning service is a barcode reader that needs to scan all package labels as they travel along a fast moving conveyor belt For details see p 166 Modbus The Modbus messaging service comprises client and server services The client Messaging initiates a request to the server using the Modbus protocol the server responds to the client s request resulting in information exchange Modbus messaging supports both reading and writing of data as well as a set of programming commands Modbus messaging should be used when data needs to be exchanged between two devices at irregular intervals or infrequent periods An example is a command to start a proc
122. needs to be serviced Because of potential delays this service is not recommended for time critical messages where short response times and quick intervention are important For details see p 217 31006929 8 2007 159 Services Overview Embedded Diagnostics Standard Web Services Web FactoryCast Embedded diagnostics can be used to execute diagnostic and maintenance functions locally and remotely with a simple Internet browser The embedded diagnostics service uses an embedded Web server and a real time data server All data is presented in HTML standard Web format which can be accessed from any Internet browser This service is a convenient way to monitor the health of devices on the network and operational and configuration information Some automation devices support remote configuration via Web pages For example Altivar drives provide access to current speed information and allow acceleration rates to be configured through their Website For details see p 223 Using a simple Internet browser the FactoryCast Web server provides all the benefits of a standard embedded Web server service with the ability to control configure and monitor plant data locally and remotely Monitoring and control can be enhanced with user customized Web pages The Web FactoryCast service is used to display and modify all plant variables in real time It lets you create hyperlinks to external Web servers that can include pla
123. not apply for more of the limited number of IP address numbers Network traffic is reduced by sending messages to only a limited segment of the network Subnetting can be particularly helpful on a network that handles a lot of broadcast traffic It can also be useful if you have a slow WAN link connecting your far flung locations To subnet the default subnet mask for a network is extended to cover bits of the address that would otherwise be part of the host field Once these bits are masked they become part of the network field and are used to identify subnets of the larger network Choose a subnet of a size number of addresses appropriate for the number of devices on it a size that allows for growth but is not wasteful of addresses For example if you have 50 devices choose a subnet of 64 addresses not 1024 The following table contains one column presenting the number of addresses and another with the corresponding mask Subnet Mask Number of Addresses 0 0 0 0 4 294 964 086 128 0 0 0 2 147 482 048 192 0 0 0 1 073 741 024 224 0 0 0 536 870 512 240 0 0 0 268 435 256 248 0 0 0 134 217 628 252 0 0 0 67 108 864 254 0 0 0 33 554 432 255 0 0 0 16 777 216 255 128 0 0 8 388 608 255 192 0 0 4 194 304 255 224 0 0 2 097 152 255 240 0 0 1 048 576 132 31006929 8 2007 Planning and Layout Subnet Mask Number of A
124. of internal memory 180 31006929 8 2007 Services Overview Modbus TCP IP Modbus Messaging Summary The same application protocol is used for Modbus serial link Modbus Plus and Modbus TCP This interface routes messages from one network to another without changing the protocol Because Modbus is implemented above the TCP IP layer you can also benefit from the IP routing which enables devices located anywhere in the world to communicate regardless of the distance between them Schneider offers an entire range of gateways for interconnecting a Modbus TCP IP network to already existing Modbus Plus or Modbus serial link networks For further details consult a Schneider Electric regional sales office The IANA institute has assigned to Schneider port TCP 502 which is reserved for the Modbus protocol The transfer of information between a Modbus client and server is initiated when the client sends a request to the server to transfer information to execute a command or to perform one of many other possible functions After the server receives the request it executes the command or retrieves the required data from its memory The server then responds to the client by either acknowledging that the command is complete or providing the requested data The system response time is limited by two main factors the time required for the client to send the request receive the response and the ability of the server to answer within
125. of network topologies an overview of applicable standards for offices and plants overall design considerations and recommendations for selecting components The installation section describes EMC installation and the installation of cables and connectors The section on verification discusses methods for your network This chapter contains the following sections Section Topic Page 2 1 Required Standards 28 2 2 Physical Planning and Layout 34 2 3 Environmental Requirements 67 2 4 Selection of Industrial Ethernet Components 77 2 5 Installation 93 2 6 Verification of a Transparent Ready Industrial Ethernet 114 2 7 Additional Considerations for Designing a Transparent Ready 121 Industrial Ethernet Network 31006929 8 2007 27 Planning and Layout 2 1 Required Standards At a Glance Overview Office based Ethernet standards are being enhanced and modified to meet industrial Ethernet requirements These Ethernet standards are being combined with industrial standards to account for the environment in which an industrial Ethernet must operate and its performance and topology requirements Many standards are used to define industrial Ethernet These standards are developed and maintained by different standards organizations and are related to the following e protocols e the physical layer e environmental requirements e cabling structures e cable specifications Many of
126. of the EN 50174 1 2000 standard A summary of those guidelines is included here The components of a cabling system are typically maintained by more than one person and therefore require the use of identifiers to indicate relevant information about the component For example you should place an identifier in the form of a label or code indicating where a shielded twisted pair CAT 5E cable is installed in the horizontal cabling system in a building Chapter 7 5 of the EN 50174 standard specifies which cabling components require such identification Labeling cables and components is a required practice in installation Either attach labels to the component or affix them as part of the component itself In some cases certain components are labeled more than once A general rule is to label a cable at both ends as the minimum requirement The following requirements are specified in the EN 50174 1 standard e Labels need to be e easy to access e easy to read e easy to change or modify if required e Labels need to be robust and their markings readable for the lifetime of the cabling e Labels should not be affected by dampness or become smudged when handled e Labels intended for outdoor use or use in harsh environments need to be designed to withstand the rigorous conditions of such environments e When you make changes to a cabling system for example at a patch panel inspect the labels to determine if the information is correct or
127. other parts of your network A firewall can also be installed between the PLC and the Internet to restrict the type of access users have to the PLC Presently no available firewalls permit Modbus data commands reading writing of data while also preventing programming commands programming the PLC using Concept Proworx or Modsoft If you are planning to permanently connect your PLC to the Internet Schneider Electric recommends working closely with personnel from your IT department or if they are unavailable partnering with a reputable local ISP 148 31006929 8 2007 Planning and Layout Security Issues Summary There are many different aspects to network security Network security includes allowing an operator day to day access to a PLC the prevention of damaging but non malicious activity and the enforcement of plant procedures and authorizations However preventing malicious activity is much more difficult than these other areas of security Malicious activity includes unauthorized access interference with corporate data virus attacks denial of service spoofing of Websites and email as well as fraud and other criminal activity Securing your network against malicious intent is very difficult to implement and requires the advice of security experts The amount of time required to secure the network against breaches depends on the level of skill the attackers possess but prevention requires constant monitoring Securi
128. period the bit stays on The health bit turns off if the data exchange is not complete resolved successfully in the health time out period The health timeout should be longer than the repetetive rate For a Quantum NOE Ethernet module the health timeout must also be longer than the CPU scan time due to the link with the CPU scan cycles A diagnostic word is provided for each I O scanner exchange This word provides additional diagnostic information on fault codes Implementation is platform specific The I O scanner opens a single TCP socket for each configured data exchange A device configured for multiple exchanges has multiple sockets The I O scanner uses source TCP port numbers in the range of 3000 4000 31006929 8 2007 173 Services Overview Repetition Rates Summary The repetition rate is the rate at which you configure the I O scanning service to exchange data Effective The effective repetition rate is the actual rate at which data is polled from the remote Repetition Rates devices This rate may differ from the configured repetition rate on different PLC platforms and option modules The effective rate is determined by the way the I O scanning service is installed The effective repetition rate is limited by e the I O scanning service timer e remote device response times e CPU scan time and data transfer time A new request cannot be issued until after the remote device responds to the previous
129. program transfers management of device operating modes link and device diagnostics and transmission of unsolicited data UTP unshielded twisted pair One or more cable pairs surrounded by insulation UTP is commonly used as telephone wire V VijeoLook PC Base HMI Human Machine Interface software from Schneider S D VPN virtual private network A network that connects private networks with remote sites using a third party service provider VSD variable speed drive 540 31006929 8 2007 Glossary Ww WAN wide area network A network using common carrier transmission services for transmission of data over a large geographical area WEP wired equivalent privacy A security protocol for wireless LANs that encrypts data transmitted over radio waves workgroup Configuration in which a number of users are connected to an Ethernet network via switching a switch Switching allows each user to get greater throughput than would be available through a hub X X Way The addressing mechanism at the network layer for the Uni TE protocol It enables XVM symbols file several Ethway Ethernet TCP IP and or Fipway networks or segments to be interconnected On TCP IP Ethernet X Way and IP addressing are used in conjunction File extension of exported variables from Unity Pro used by OFS 31006929 8 2007 541 Glossary 542 31006929 8 2007 Index Numerics 100Base TX standard for twisted pair Et
130. request and starting the next CPU scan 31006929 8 2007 193 Services Overview Modbus Server Operations in Momentum Systems Momentum Implementation Momentum Modbus Server Operation The Momentum PLC implements a Modbus server as part of the main CPU There is no limit on the number of Modbus requests that can be answered by a Momentum CPU The Modbus server for Momentum CPU operates as follows Sequence Event 1 The Modbus client establishes a TCP socket to the Momentum CPU which may take several CPU scans 2 On the first scan a SYN is received and is sent back to the client at the end of the scan The Modbus client sends a request along the TCP socket The CPU receives the request The request is answered at the end of the next CPU scan 194 31006929 8 2007 Services Overview Modbus Servers and Socket Limits Simple Modbus Servers Modbus Server TCP Socket Limits Product Response Time Advantys 4 5 ms ATV58 Drive 30 ms Momentum ENT1100 02 1 ms additional 4 5 ms to include I O base Momentum ENT1101 5 9 ms Note The response times above do not include I O reaction times Product TCP Socket Limit Quantum NOE modules NOE77100 10 32 Quantum NOE modules NOE77101 11 64 all Ethernet services combined Premium ETY410 510 32 all Ethernet services combined Premium ETY
131. requests per CPU scan In this scenario it takes 2 CPU scans 280 ms to answer the 4x and 3 CPU scans 420 ms for Ox requests which is much faster than the first case If the user sends a write command to the PLC to start the motor there are several possibilities e Case 1a The SCADA may interrupt the polling and send the request right away after the current request is finished the motor starts two CPU scans later one CPU scan to finish the current request and another to process the request to start the motor e Case 1b The SCADA may place the request at the end of the queue it takes up to 2 94 seconds before the write request is sent The motor starts one CPU scan after this time e Case 2 The request is sent and is queued at the end of the other ox requests in the NOE module This is processed on the third CPU scan the delay is 3 CPU scans 420 ms For more information see p 189 Problem 4 Problem A Quantum PLC is reading data from a Premium PLC Thee Quantum s scan time is 50 ms and the Premium s scan time is 70 ms What is the response time of the system to read a block of 50 Modbus 4x registers Answer For Quantum to Premium communications there are two methods using the graphs in the appendix or calculating from the system operation The one block of 50 Modbus registers can be read in a single Modbus request Look for a single Modbus messaging request to a device with a response time of 70 ms 70 ms is
132. response time from a field input on a scanned device to a field output activated at another scanned device due to PLC logic triggered from the first input CPU scan time is 50 ms The scanned device response time is 10 ms PLC System Number of Device Scanned 1 16 32 Quantum or Premium with NOE ETY non Unity 110 ms 115 ms 125 ms Quantum or Premium Unity CPU with embedded 100 ms 105 ms 115 ms Ethernet port 178 31006929 8 2007 Services Overview 3 3 Modbus Messaging At a Glance Overview This section describes the Modbus messaging service This service handles the Modbus protocol and enables data transfers between network devices What s in this This section contains the following topics Section Topic Page Modbus Messaging Service Description 180 Devices that Support Ethernet Modbus Services 184 Modbus Client Operations in Quantum Systems 185 Modbus Client Operations in Premium Systems 186 Modbus Client Operations in Momentum Systems 188 Modbus Server Operations in Quantum Systems 189 Modbus Server Operations in Premium Systems 192 Modbus Server Operations in Momentum Systems 194 Modbus Servers and Socket Limits 195 Modbus Messaging Retry Times and Time outs 196 31006929 8 2007 179 Services Overview Modbus Messaging Service Description The Modbus Messaging Services Modbus Communication Standard Modbus TCP
133. second provides more specific results for a particular system than the total time graphs used in method one The measured response times for several of Schneider s Modbus client systems based on various server response times are described in an appendix see p 405 These response times were measured under controlled conditions and may vary from results obtained in the field The graphs in this appendix are valid only when the overall limits of device communications are not exceeded on the client or the server The following devices may require the calculation of the Modbus messaging client time as it is not fixed Quantum PLC system Premium PLC system Momentum PLC system SCADA system OFS server 31006929 8 2007 325 Services Overview Quantum PLC System For a Quantum system the Modbus messaging request is sent immediately when the function inside the user logic is triggered When the response is received from the Modbus server that response is processed in the user logic memory the next time the calling function is processed This is normally during the CPU scan immediately after the PLC system has received the message Time CPU NOE Scan Start Request Block triggered Request Sent gt gt A Response Scan lt Request Block response v If this is the only request being sent or there are no prior requests in the queue the response time is response time server response time 1 C
134. select components or begin to install your Transparent Ready industrial Ethernet network 2 Use approved tools to measure and verify the quality of your installation and its conformance to regulations 3 Use local and or internationally certified installers of Ethernet networks 31006929 8 2007 115 Planning and Layout Permanent Links Summary Example 1 A permanent link used for testing is a horizontal cable with an outlet for a workstation a patch panel and 2 m of extra cable at each end for testing It can be a maximum of 90 m in length in accordance with standard 568B of TIA EIA It consists of only the passive sections of a cable and the connecting hardware A transition point where cables can be connected may be included in the horizontal subsystem of a link The permanent link goes from the RJ45 jack connector on one end of a cable to the RJ45 jack on the other When a tester is connected to the cable the effect of the tester cable and the other tester equipment connected to the cable is automatically removed from the measurement by the tester The same removed measurement occurs with the cable between the last RJ45 jack and the remote indicator required by the tester A permanent link between a floor distributor FD and terminal outlet TO is shown below A transition point TP is included in the horizontal subsystem FD TP TO _ a M gt 1 permanent link
135. server for a set of IP parameters that is used by a device with this rolename 4 The device receives the IP parameters and then connects to the FDR server and downloads a copy of its operating parameters 5 After the parameters are downloaded the device implements the parameters and operation resumes The actual parameters may include a device consistency check to see that the replacement device is of the same type as the original Based on this check the client may choose to operate even if the replacement device is different from but still compatible with the original device FDR should be used for all devices that support this service on an automation network As Schneider Electric adds FDR support into more of its devices plants should be updated At the present time the service focuses on I O devices not on PLC or HMI systems In Hot Standby system you are unable to use the FDR server Only one FDR server is permitted on a subnet see p 132 If you reach the limit for FDR clients on a network split the network and assign a new FDR server to the newly established network 206 31006929 8 2007 Services Overview Devices that Support the FDR Services Device FDR Client FDR Server Quantum 140CPU65150 140CPU65160 140NOE77101 140NOE77111 Premium TSXP571634M TSXP572634M TSXP573634M TSXP574634M TSXP575634M TSXETY4103 TS
136. should be monitored back up links on primary and all links on the standby PLC to detect and correct link failure before the link is needed The standby link status should also be known so the PLC can determine if the changeover re establishes communications If communications are not re established the changeover will not improve plant control redundancy Also a changeover can affect other devices The standby communication links in the primary PLC are monitored in the same way as the primary link They can be monitored with aRead Local Statistics command or with a full watchdog A full watchdog for the standby PLC is different from a watchdog on the primary PLC because the standby PLC is not always processing code Use the reverse transfer registers of the hot standby system to transfer the register written by the SCADA system to the primary PLC and increment the register there Then transfer the register either back to the SCADA system using the primary PLC s communication links or back to the standby PLC using the hot standby link where the SCADA system reads the result Current Quantum hot standby systems allow a small amount of code to be executed in the standby PLC The code can be used to execute the Read Local Statistics command and place the results in the reverse transfer registers for transfer to the primary PLC 300 31006929 8 2007 Services Overview PLC IP Addresses Manual Hot Standby PLC Changeovers C
137. subset of the elements has changed values 262 31006929 8 2007 Services Overview Note In the wake up function processes that take up a significant amount of CPU time e g an overly complex display should not be performed These kinds of processes can adversely affect the Operating System s performance The following issues relate to the notification service e Assigning a scanning period rate to a group enables you to scan the PLC variables at different periods For example you can display the PLC time every second and the temperature every minute e Allocate deadband to a group so that notifications are filtered when group variable values change Notification occurs if variables change by more than a certain percentage of their previous value after the group scanning period For example the client application is informed only if temperature changes by more than 10 OPC OFS EXE Interfaces OPC Server Enable Event Data Back to Application Code Update Back to Application Code Note Deadbanding is applied only to floating point or integer variables so that you can control or limit the flow of notifications sent to the client application and thereby avoid overloading the system 31006929 8 2007 263 Services Overview OFS Performance Summary The following discussion describes the static characteristics of OFS and defines some rules for genera
138. switches between the server and client e the implementation of a separate network possibly a VLAN for the NTP system 362 31006929 8 2007 Troubleshooting Web Troubleshooting Table Cannot Access Static Pages Cannot Access Dynamic Data Topic Problem Solution Firewalls Make sure you have the appropriate security access for all devices that you try to reach Also the firewall should be configured to allow access to your HTTP request Proxy server A proxy server can allow access to only the appropriate Web pages through filtering Make sure the proxy server does not filter out the Web page you want to reach Topic Issue Java version If you can see the Web pages but not the dynamic data like Ethernet statistics the Java applet may not be compatible with your JVM A gray Java box or an error in the status bar at the bottom of the Web browser window indicate this problem firewall blocked If this is the case you see either A firewall can also block the particular application protocol like Modbus TCP and Uni TE 502 so you can not see live data For example a Web page that can not display real time data indicates that protocol 502 is question marks in the data fields or e an error indicating that the Modbus device can not be reached browser security setting You can not download Java applets if you chose high security s
139. the Internet standard for multicasting IGMP snooping inter networking Interbus interface broadcast mapping Internet IP address IP rating that allows a host to subscribe to a particular multicast group Allows a switch to snoop or listen in on messages between a router and hosts General term used to describe the industry composed of products and technologies used to link networks together An open communication standard that offers a high speed network for the connection of I O modules sensors actuators and control devices to programmable logic controllers or large computer systems A proprerty that maps the rate of the broadcast traffic coming into each port of the managed switches Aseries of interconnected local regional national and international networks linked using TCP IP Internet links many government university and research sites It provides E mail remote login and file transfer services The 32 bit address associated with a workstation in connection with TCP IP Internet internal protection rating Describes the degree of protection for the internal circuitry of the sensors 526 31006929 8 2007 Glossary ISDN integrated services digital network A set of standards for digital transmission over copper telephone wires ISO layered The International Standards Organization sets standards for computers and model communications Its open systems interconnection OSI reference
140. the RJ45 discussed by the IEC 61076 3 106 This topic is under heavy discussion due to the fact that there are multiple sealed RJ45 non compatible models The housings cover a variety of different mating dimensions round or rectangular locking mechanisms screw bayonet locking lever push pull and other special features The different variants are not mateable For heavy duty environments the choice seems to be the circular connector M12 already defined by the IEC61076 2 101 standard The type of M12 connector to use is still under discussion due to the preference for 4 pins in Europe and the preference for 8 pins in the US The 4 pin connectors are more prevalent in Europe which corresponds to the European practice of employing a 2 pair cable in Ethernet service instead of the 4 pair cable specified by TIA the US based telecommuni cations standards body 31006929 8 2007 493 Standards and Considerations Conforming to Standards Introduction At this time there is no international standard for planning and installing an industrial Ethernet network There are recommendations from industrial Ethernet organizations and ongoing activities that have resulted in the creation of a draft for such a standard Plans are to publish this standard as ISO IEC 24702 by the end of 2006 ISO IEC 24702 Because the forthcoming ISO IEC 24702 is based on the ISO IEC 11801 standard and ISO
141. the data storage and management responsibilities A PLC may act as a server for some devices and as a client for others The industrial network shown above is very different from a typical business and commercial applications Due to the critical nature of many control applications client devices throughout the industrial Ethernet system tend to be more intelligent than standard commercial Ethernet clients The ways in which the client and server devices communicate with each other are defined by the Transparent Ready services that they use A business Ethernet network is designed with a bank of servers residing in a control room Business data is stored and managed in this centralized area and is sent to and from the clients through switches and routers dispersed throughout the enterprise Firewalls secure the enterprise from unauthorized entry Industrial Ethernet is different from commercial Ethernet in three main areas environmental layout and performance requirements Office Ethernet Industrial Ethernet Environment Suitable for human Light duty and heavy duty industry occupancy and work Normal temperature range Potential harsh environments Little dust moisture and Exposure to electromagnetic noise vibration Hardly any mechanical Extreme temperatures climatic loads or problems with variables chemicals Low EMC requirements D
142. these standards are regional and may apply only to specific areas or countries What s in this This section contains the following topics i Section Topic Page On going Industrial Ethernet Standardization Efforts 29 Required Standards for Planning and Installation 32 28 31006929 8 2007 Planning and Layout On going Industrial Ethernet Standardization Efforts Introduction ISO IEC 24702 Standard Time Table and Definitions There are as yet no industrial Ethernet planning standards to refer to for guidelines and rules There are however many recommendations for industry based on the office environment standards TIA EIA 568 B ISO IEC 11801 and EN 50173 that have been placed before standards committees by several industrial networking organizations The most significant international standardization effort is by a collaborative group of experts from IEC TC65 TIA TR 42 9 and CENELEC TC215 WG1 Their work will be published as the ISO IEC 24702 standard TIA TR 42 9 CLC TC215 WG1 PTP ISO IEC JTC1SC26 IFTG Publication of the ISO IEC 24702 standard is planned for sometime in 2006 The ISO IEC 24702 standard defines generic cabling for industrial premises and related IT specifications For its definition of balanced cabling and optical fiber it takes the following from ISO IEC 11801 e applications e link and channel transmission classes e transmission performance components It also
143. times for all requests The performance is based on network baud rates of both 9600 and 19 200 and on the amount of data i e the number of registers requested The following legend describes the baud rate and number of requests sent as tracked in all four of the charts that follow Curve Number of Requests Baud Rate 1 16 9600 2 19 200 3 8 9600 4 19 200 5 1 9600 6 19 200 474 31006929 8 2007 Gateway Performance Serial Devices with 50 ms Response Time 9000 8000 5 7000 4 ae 6000 4 6pe ai aa a 50004 en a lt y E 2 _ Opis o 4000 4 ai _ 2 er le E Ea E A mm ae 3000 4 2000 4 6 1000 4 0 0 20 40 60 80 100 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 50 CEV30020 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 2151 33 2594 663333 3101 33 2144 67 2541 336667 2994 67 138 16 2151 33 2944 663333 3851 33 2144 67 2716 336667 3369 167 138 32 2151 33 3317 333333 4651 33 2144 67 2903 166667 3769 67 138 64 2151 33 4064 996667 6251 33 2144 67 3276 336667 4569 67 138 100 2151 33 4904 663333 8051 33 2144 67 3696 336667 5469 67 1
144. to 1 w Time for next exchange End of CPU scan Transfer data to CPU memory va 3 ee 170 31006929 8 2007 Services Overview Write Operations 1 If the remote device does not support FC23 the I O scanner uses FC3 and FC16 to execute the data transfer When this happens the read operation is performed in the first exchange and the write operation is performed in the next exchange The total read write operation takes twice as long as the time required for the FC23 operation to execute 2 The timing of this loop is affected by the repetition rate 3 All I O scanner entries exchange data with the CPU at the end of the scan The I O scanning service writes data from a memory zone in the I O scanner device to a memory zone in the remote device Depending on the I O scanner device the memory holding the values to be sent may be 16 bit registers AMW or 4x or blocks of bits M or Ox The data is always written to 16 bit registers in the remote devices 31006929 8 2007 171 Services Overview Read Operations Error Handling Enable Disable The I O scanner device reads data from memory zones in the remote devices to gather field device or input status The remote devices always store this status data in 16 bit registers After the data is read it can be stored in 16 bit registers MW or 4x or blocks of bits M or Ox in the I O scanner device s memory
145. too often e g 500 ms 700 ms 900 ms A better solution is to link the polling of the groups Link the polling so that one group has to finish before another group can be polled This solution prevents 31006929 8 2007 279 Services Overview Blocking e an overload of requests that are waiting to be answered by the field devices resulting in communications failure e a queue of requests forming in the SCADA system or field device Some SCADA systems automatically link the polling of groups Others require you to manually implement this function For reading or writing the same type of data the same Modbus function code the SCADA system may try to combine multiple tags into a single data transfer for efficiency This is not normally done for write commands except when you are writing tables of data The way a SCADA system combines values into a single read is known as blocking Blocking can improve the efficiency of the overall system communications EES BEE E ee mE Boe pe AXXX BREE BE EES E EE EE For blocking to be most efficient the variables in the field device should be located so that all the data required by the SCADA system is together in the Modbus memory area When defining groups that the SCADA system polls arrange the variables inside the field device so that all variables within a group are adjacent to each other Even if you are not arranging the groups to
146. traffic as the SCADA server to client traffic can be optimized to transfer all data to a client instead of the client gathering information from each field device traffic can be separated onto another network instead of the plant control network The following illustration shows three completely redundant SCADA systems all polling the PLC Back up I O server 3 O server1 lt b I O server 2 1 Two separate SCADA systems both polling the PLC 2 Two display clients polling a primary I O server The back up I O server only monitors the health of the connections to the PLC 3 Two display clients polling an I O server where the I O server does not know that there is redundant back up It continues to poll all data from the PLC 292 31006929 8 2007 Services Overview SCADA SCADA system planners need to consider redundancy from communications to Communication redundant devices For a redundant device to communicate the SCADA system to a Redundant must be able to exchange the same data with what it considers to be two devices Device For example a Quantum PLC system that contains two NOE modules allows the SCADA system to exchange data with the PLC CPU using either NOE module If one module fails or the network attached to this module fails communications continue using the other NOE module The SCADA system may be able to automatically manage communications to redundant devices or you may need to manage com
147. use e PC based These tools use a PC s Ethernet card to capture network data for analysis in a software program Owing to wide fluctuations in price from freeware to more than USD 20 000 the degree of automatic analysis and customer support services for these tools significantly vary These tools analyze only layers 2 3 and 4 Ethernet packet capture tools can detect or determine e overall network traffic load Which devices contribute to congestion What is the nature of the traffic VoIP Windows broadcast I O scanner traffic e broadcast traffic and its causes e alist of devices to which a specific device transmits and the communication protocol it uses e details of communications between devices protocols function codes the addresses and values of transferred requested data e a device s application layer response time packet loss or multiple TCP retries e communications to and from a device that suffers from TCP socket errors rejected connections lost packets etc All Ethernet packet capture tools can analyze all of these items but better tools do analysis automatically and report errors on the alarm screen 368 31006929 8 2007 Troubleshooting Packet Capture Troubleshooting Problem Category Topic Suggestions Packets from the required device are not seen only packets to or from the host PC are captured by the tool The package does not operate in promiscuous mode E
148. user accounts have been created correctly and check system logs for authentication attempts The local system administrator can help you with this 31006929 8 2007 353 Troubleshooting 4 3 Services Troubleshooting At a Glance Introduction This section describes common problems and actions for correcting a communications error on Transparent Ready services Troubleshooting of this nature is simpler for some devices than for others because diagnostic information is provided by different devices The complexity of the troubleshooting also varies between Schneider products and third party devices A device s indicator lights and the information provided by its diagnostic or programming software can aid with troubleshooting In some cases you can use a network packet capture tool see p 368 This tool can accurately diagnose the problem on a service and indicate a single corrective action It can take awhile to set up the tool so you may want to attempt an intuitive solution swapping a suspect device or modifying a service configuration before attempting to perform analysis with the packet capture tool What s in this This section contains the following topics Section Topic Page Services Troubleshooting 355 Modbus Messaging and I O Scanner Troubleshooting 356 SNMP Troubleshooting 358 Telnet and FTP Troubleshooting 359 Faulty Device Replacement BootP Troublesh
149. using the Modbus TCP IP communications system Monitor Pro implements user defined groups allowing you to configure the tags to be read in each group You can trigger the reading and writing of each group via a user defined tag It can be a time based tag for reads or a customized tag For writes the tag is automatically set whenever an item in the group is changed and only that item is written For reads the entire group is read Groups can be sequenced by preventing the control tag for one group from being triggered before the completion flag is set for the previous group Monitor Pro uses a TCP socket for reads a separate socket for writes and another separate socket for exception reads Each socket allows a single Modbus messaging request to be outstanding on the device at a time You can create an additional instance of the Modbus communications task and spread the variables to be read between the two tasks Because additional requests can be sent to the field device at the same time system performance is faster Monitor Pro creates a queue inside itself for any communications requests that are triggered but cannot be sent to the PLC because of outstanding requests on a socket These requests go into the Modbus TCP IP task mailbox The mailbox can eventually overflow and cause communications to cease 286 31006929 8 2007 Services Overview 3 14 Redundancy At a Glance Overview This section cover
150. where the wireless network meets the main network This adds additional encryption stronger than WEP to the data being transmitted Run a firewall between the VPN endpoint and the rest of the network to further restrict access 152 31006929 8 2007 Services Overview At a Glance Overview What s in this Chapter This chapter gives you the information you need to select the correct Transparent Ready service for each task in your automation system It provides information about the benefits and limits of each service and it discusses the operation of devices that use the service Note The Unity performance data used in this chapter are based on version 2 0 of the software Other Unity versions may be significantly different This chapter contains the following sections Section Topic Page 3 1 Evaluating System Requirements 154 3 2 I O Scanning Service 166 3 3 Modbus Messaging 179 3 4 Global Data Service 197 3 5 Faulty Device Replacement 204 3 6 Time Synchronization 208 3 7 Electronic Mail Notification Service 217 3 8 Standard Web Server 223 3 9 FactoryCast Web Server 230 3 10 FactoryCast HMI Web Server 236 3 11 Other Services 242 3 12 OPC Factory Server 256 3 13 SCADA HMI 274 3 14 Redundancy 287 3 15 Gateway Bridge Systems 304 3 16 Supported Services per Device 312 3 17 System Performance Evaluation 319 31006929 8 2007
151. 0 ENT 110 02 Advantys STB STBNIP2212 Altivar ATV 38 58 VW3 A58310 Power Logic Gateway EGX200 EGX400 31006929 8 2007 229 Services Overview 3 9 FactoryCast Web Server At a Glance Overview The section describes how to use the FactoryCast Web server to control and monitor plant operations What s in this This section contains the following topics ion Section Topic Page FactoryCast Web Server 231 FactoryCast Web Server Operation 233 Devices that Support FactoryCast Web Server Services 235 230 31006929 8 2007 Services Overview FactoryCast Web Server Summary Hosting and Displaying User Web Pages Configuration Software for FactoryCast Web Servers A FactoryCast Web server is an extension of the standard Web server that provides plant diagnostics and control through customized Web pages The following functions are available e management of device and plant alarms with partial or global acknowledgment ready to use pages for the alarm viewer function e graphical plant diagnostics customized user generated graphical views using the graphic data editor function e graphical plant control via user generated animated Web pages that are stored in the FactoryCast module The customized Web pages are transferred to the module using FactoryCast configuration software FactoryCast Web modules have a memory area that hosts user generated
152. 0 ms Communications Completed The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 200 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 are are 1 1 1 ai 1 a 1 an OINI OO a RA OJN 11 12 13 14 15 16 17 OPN NMI NIN NIM MIN NM MW NMI NM Uj v vlv NIM MI NM NM NI NIN ay a A AR WO oO wow oJ A NINNIN N N N OJo AD al a a BR BYR WO WwW wo wo hy Mw My jol SI NINI DIO a Aa AJ Bl WwW Ww Ww mM ny bv 426 31006929 8 2007 Modbus Client Performance At a CPU Scan Time of 100 ms CPU Cycles 0 2 4 6 8 10 12 14 16 18 Communications Completed The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 100 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 1 2 2 1 1 1 1 2 2 3 1 1 1 2 3 4 4 1 1 2 2 3 4 5 1 1 2 4 4 5 6 1 2 3 4 4 6 7 1 2 3 4 5 7 8 1 2 3 4 5 8 9 1 2 3 5 6 9 10 1 2 4 5 7 10 11 1 2 4 6 8 11 12 2 3 4 6 9 12 13 2 3 4 7 9 13 14 2 3 4 7 10 13 15 2 3 4 7 10 14 16 2 3 4 8 11 15 17 2 3 4 8 11 16 3100
153. 000 4 1000 4 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 50 CEV300200 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 201 3333333 644 6666667 1151 833333 194 6666667 591 8333333 1044 166667 138 16 251 3333333 1044 666667 1951 833333 219 6666667 791 8333333 1444 166667 138 32 304 6666667 1471 333333 2804 166667 246 3333333 1004 166667 1871 833333 138 64 411 3333333 2324 666667 4511 833333 299 6666667 1431 833333 2724 166667 138 100 531 3333333 3284 666667 6431 833333 359 6666667 1911 833333 3684 166667 138 470 31006929 8 2007 Gateway Performance Serial Devices with 100 ms 8000 4 Response Time 7000 6000 a 5000 4 4000 Time ms 3000 2000 4000 _ Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 100 CEV300200_ Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 251 33333 1044 66667 1951 333333 244 66667
154. 006929 8 2007 221 Services Overview Devices that Support Email Notification Device Security Feature Maximum Number of Headers Variables in Message Body Dynamic Email Body Content Premium TSXP571634M v3 1 or higher TSXP572634M v3 1 or higher TSXP573634M v3 1 or higher TSXP574634M v2 0 or higher TSXP575634M v2 0 or higher TSXETY4103 v3 1 or higher TSXETY5103 v3 1 or higher XxX XxX X X Xx x Xx XIX X X Xx x x TSXWMY100 v vl olv v vja fo oO Quantum 140CPU65150 v2 0 or higher ro t 140CPU65160 v2 0 or higher 140NOE77101 v3 5 or higher s 140NOE77111 v3 5 or higher x Xx Xx Xx x x Xx Xx 140NWM10000 v WwW wo w fo oO X XI X X X X XxX XK OK X X Xx 222 31006929 8 2007 Services Overview 3 8 Standard Web Server At a Glance Overview The section describes a service that uses a standard Web browser to diagnose and configure Transparent Ready devices What s in this This section contains the following topics ion Section Topic Page Web Server Services 224 Web Server Operation 226 Devices that Support Standard Web Server Services 229 31006929 8 2007 223 Services Overview Web Server Services Summary Embedded diagnostics are used to execute diagnostic and
155. 006929 8 2007 Services Overview Multiple Here is an example of a single socket that supports multiple requests in this case Requests ona 10 Single Socket i OC H f LS i LS j L 10 requests answered j E in parallel l CO l j LS ed ee os a O m m 8 requests unable lt oT Unused capacity for 6 to be sent additional answers E Ea e ee a a The SCADA system opens a single socket to the field device but is able to send 10 requests to the end device without waiting for an answer The end device can start answering all 10 requests without delay This system provides a faster response time but can also overload an end device if the device cannot handle 10 requests at once Even if the device can handle the 10 requests it may not be able to handle more than one request at a time on a single TCP socket This is common in older devices or devices that do not use the Modbus TCP transaction ID The response time of the system is 150 ms instead of 1 5 s as in the previous example 31006929 8 2007 283 Services Overview Multiple Sockets Here is an example of a SCADA system that uses 10 separate sockets to send Sending One requests to the field device but only sends a single request down each socket This Request at a system handles devices support only a single request per socket Time a E ay 10 requests answered pm ____d in parallel m y 16 sockets establish
156. 100 174CEV30020 X X 174CEV20030 X X Telnet Device Configuration Diagnostics Security 174CEV30020 X X X 174CEV20030 X X X 31006929 8 2007 255 Services Overview 3 12 OPC Factory Server At a Glance Overview This section describes OFS OPC Factory Server and provides examples of how to implement these servers in Transparent Ready systems What s in this This section contains the following topics Section Topic Page OPC Factory Server 257 OFS Services 261 OFS Performance 264 Runtime Architecture for Unity OFS SCADA a Simple Example 267 Build time Runtime Architecture for Unity OFS SCADA Systems that Are Not 268 Frequently Modified Build time Runtime Architecture for Unity OFS SCADA Systems that Require 270 Frequent Modification Build time Runtime Architecture for a System with Multiple SCADA 272 Connections 256 31006929 8 2007 Services Overview OPC Factory Server Summary OPC data access is used to move real time data from PLCs DCSs and other control devices to display clients such as HMI panels The OPC specification defines a standard set of objects interfaces and methods for interoperability in process control and manufacturing automation applications The specification was originally based on Microsoft s OLE component object model and distributed component object model technologies OPC factory server OFS is a multi
157. 2 orange 3 green striped 4 blue 5 blue striped 6 green 7 brown striped 8 brown 31006929 8 2007 105 Planning and Layout Crossover Cable Crossover Cable Pinout When two end devices on an Ethernet network communicate with each other over a direct connection the transmit signals of one device must connect with the receive signals of the other and vice versa Use a crossover cable whenever you make a direct connection between two end devices A direct connection has no intermediary device between the two end devices you are connecting Q 1 TX TX TX TX RX RX RX Z RX 2 1 end device 2 crossover cable The EIA TIA 568B standard defines the pinout for an Ethernet crossover cable A direct pinout connection between two end devices uses a crossover cable that follows the specifications shown in the diagram below Signal Signal in jack end device RJ45 Pin RJ45 Pin l in jack end device TX 1 1 RX TX 2 2 RX RX l 3 3 TX Unused l 4 4 Unused Unused l 5 5 Unused RX 6 6 TX Unused 7 7 Unused Unused 8 8 Unused End Device I Crossover Cable End Device orange striped orange green striped blue blue striped green brown striped brown ONO RWND 106 31006929 8 2007 Planning and Layout MDI MDI X Today most of the infrastructure devices offered on the market hubs switches routers etc support
158. 31006929 01 Merlin Gerin Transparent Ready User Guide 8 2007 Schneider Electric Table of Contents Chapter 1 Chapter 2 2 1 2 2 2 3 2 4 Safety Information 200 00 cee cece eee ees 9 About the BOOK ihe Meee eeu ie eae eae ee tee el 11 Transparent Ready 00c cece eect eee eee eee 15 Transparent Ready 0 60 e eee eee eee 16 Transparent Ready Service Classes Offered 00000 ee eeaee 19 Users of this Guides ma raices a seated Heth aes b BA ede ds 23 How this Guide Is Organized 1 0 0 0 aaae 24 Physical Planning Design and Installation of a Transparent Ready Industrial Ethernet Network 27 Required Standards 0 0 0 cece teeta 28 On going Industrial Ethernet Standardization Efforts 29 Required Standards for Planning and Installation 000005 32 Physical Planning and Layout 00 0 0 c ee eee eee es 34 Industrial Ethernet Cable Planning 0 000 cece eee eee eee 35 Structured Cabling Standards 0 00 cee cee eee eee eee 36 Cabling in a Transparent Ready Industrial Ethernet System 40 Understanding Basic Network Structure 00 0c eee ee 43 Developing Network Architecture for Industrial Ethernet Networks 49 Redundant Ring Topology 0 cece ttt eee 53 LAN Technologies and Network Design 0 0c cece eee 55 LAN Hardware isyeie
159. 31006929 8 2007 61 Planning and Layout WAN Technologies and Network Design Summary Point to Point Links Leased Lines Circuit Switching Several LANs that reside in widely separate physical locations can be joined into a Wide Area Network WAN The WAN usually uses leased services for the connection These may include e point to point leased lines e circuit switching e packet switching e virtual circuits e dial up WAN technologies function at the lower three layers of the OSI model see p 124 the physical layer the data link layer and the network layer When planning a Transparent Ready industrial Ethernet application some factors you should consider about your WAN include the size and locations of the proposed network the amount of traffic and the cost and speed of various commercial transmission services Point to point links furnish a single pre established WAN communication path from your site through a service provider s network to your remote network The service provider dedicates wiring and bandwidth to meet the needs of your enterprise Cost is dependent on how much bandwidth you require and the distance between connection points A router can initiate circuit switched connections when they are needed then disconnect the circuit when the communication is complete The cost depends on the time that the circuit is used making circuit switching a popular backup solution for other WAN technolo
160. 312 Ethernet Services and the Transparent Ready Devices that SUpport THEM zase oea ates neared cals atk dat E a dealt E a SE 312 System Performance Evaluation 00 0 eee eee eee eee 319 System Communications 0 00 ccc eee eee eens 320 Modbus Messaging Response Times 20000 cece e eee eee 320 Modbus Server Response Times 00000 cece eee eee e eens 321 Modbus Messaging Client Response Times 002000e ee aeee 325 VO Scanner Systems 1 0 0 0 00 eee eee 329 Total Load on DeviceS anaa 000 cc eee 331 System Performance Solutions 0 0000 e cece eee eens 332 Gateway Response TimeS 0 00 e cece eee cette teens 337 Troubleshooting ois sc ieies Her tee eo ea el eee 341 About Troubleshooting 0 c eee ett 342 Introduction to Troubleshooting 00 0 eee eet eee 343 General Problem Identification 0 0 00 ee ee 344 4 2 4 3 4 4 4 5 4 6 Appendices Appendix A Ad A 2 Appendix B Appendix C Network Troubleshooting 0 cece eee tees 345 Introduction to Network Troubleshooting 000 eee eee eee 346 Connection Troubleshooting 0 0 eects 348 Intermittent Connection Troubleshooting 0 2 0 ee eee eee eee 350 Slow Connection Troubleshooting 0 0 0 cece eee ete eee 351 Remote Access Troubleshooting 00 eee eee eee eee eee 352 Services Troubleshoot
161. 38 31006929 8 2007 475 Gateway Performance Serial Devices with 100 ms Response Time Time ms 0 20 40 60 8 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 100 CEV30020 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 2151 33 2944 663333 3851 33 2144 67 2891 336667 3744 67 138 16 2151 33 3294 663333 4601 33 2144 67 3066 336667 4119 67 138 32 2151 33 3667 333333 5401 33 2144 67 3253 003333 4519 67 138 64 2151 33 4414 996667 7001 33 2144 67 3626 336667 5319 67 138 100 2151 33 5254 663333 8801 33 2144 67 4046 336667 6219 67 138 476 31006929 8 2007 Gateway Performance Serial Devices with 200 ms Response Time 12000 10000 8000 6000 a E ae o E F swo m 2000 3 oo a ae amp 6 o QV T T 40 60 80 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 200 CEV30020_ Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Brid
162. 4 5 6 2 3 3 3 5 6 7 2 3 3 4 6 7 8 2 4 3 5 6 8 9 3 4 3 5 7 9 10 3 4 4 6 8 10 11 3 4 4 6 8 10 12 3 5 4 6 9 11 13 4 5 4 7 10 12 14 4 5 5 8 10 13 15 4 5 5 9 12 14 16 4 6 6 9 12 15 17 5 6 6 10 12 16 422 31006929 8 2007 Modbus Client Performance At a CPU Scan Time of 50 ms CPU Cycles above 6 Communications Completed The table below shows the data points used to generate the graph represented 8 10 12 14 PLC Scan ms Server Response Time ms 50 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 2 1 2 2 2 1 3 2 2 3 4 3 1 4 2 3 4 6 4 1 4 3 4 6 8 5 2 5 3 5 7 10 6 2 5 4 6 8 12 7 2 5 4 7 9 13 8 2 6 4 8 11 15 9 3 6 5 9 12 17 10 3 6 5 10 13 19 11 3 6 6 11 15 21 12 3 7 6 12 16 23 13 4 7 7 13 17 24 14 4 7 7 13 18 26 15 4 8 9 15 22 30 16 4 8 10 17 22 30 17 5 8 10 17 22 32 31006929 8 2007 423 Modbus Client Performance At a CPU Scan Time of 10 ms 180 160 140 120 100 80 CPU Cycles 60 40 20 Communications Completed The table below shows the data points used to generate the graph represented above PLC Scan ms Serve
163. 410 510 Modules User Manual 3500473404 Premium and AtriumUsing Unity Pro Ethernet Network Modules User 35006192 Manual Ethernet Module Manuals for Unity 20110V20E Altivar 58 Ethernet Modbus TCP IP Communication Option VVDED300053 Instruction Bulletin Sepam series 80 functions Introduction EGX Installation Guide 63230 314 200B1 EGX User s Guide 63230 208A1 EGX Reference Guide 63230 314 202A2 You can download these technical publications and other technical information from our website at www telemecanique com Product Related Schneider Electric assumes no responsibility for any errors that may appear in this Warnings document If you have any suggestions for improvements or amendments or have found errors in this publication please notify us No part of this document may be reproduced in any form or by any means electronic or mechanical including photocopying without express written permission of the publisher Schneider Electric All pertinent state regional and local safety regulations must be observed when installing and using this product For reasons of safety and to assure compliance with documented system data only the manufacturer should perform repairs to components User Comments We welcome your comments about this document You can reach us by e mail at techpub schneider electric com 31006929 8 2007 13 About the Book 14 31006929 8 2007 Transparent Ready
164. 4102 5102 64 all Ethernet services combined Momentum CPU 12 Momentum ENT1100 02 4 Momentum ENT1101 4 31006929 8 2007 195 Services Overview Modbus Messaging Retry Times and Time outs Modbus Client The Modbus client service supports retry times at the application layer see p 125 The system also performs TCP retries to make sure that Modbus requests and responses are being delivered Modbus retry times and time outs are device dependent Platform TCP Retry Times Modbus Client Time outs Quantum 5 25 and 45s 30 s no retries Premium 5 25 and 45s user defined in the communication block with no retries Modbus Server The Modbus server service does not support retry times at the applications layer The system implements TCP retries to make sure Modbus requests and responses are delivered The retry times are device dependent Platform TCP Retry Times Unity 2 0 Quantum 50 ms 800 ms and 1 5s Unity 2 0 Premium 50 ms 800 ms and 1 5s Quantum 800 ms and 1 5s Premium 800 ms and 1 5s 196 31006929 8 2007 Services Overview 3 4 Global Data Service At a Glance Overview The global data service supports the transfer of real time information from a source device to any other device on the network that subscribes to that information What s in this This section contains the following topics
165. 5 32 354 1666667 1520 833333 2854 166667 295 8333333 1054 1666667 1920 833333 187 5 64 460 8333333 2374 166667 4560 833333 349 1666667 1480 833333 2774 166667 187 5 100 580 8333333 3334 166667 6480 833333 409 1666667 1960 833333 3734 166667 187 5 448 31006929 8 2007 Gateway Performance Serial Devices with 100 ms Response Time Time ms 8000 5 7000 4 6000 4 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 100 EGX200 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 300 8333333 1094 166667 2000 833333 294 1666667 1040 833333 1894 166667 187 5 16 350 8333333 1494 166667 2800 833333 319 1666667 1240 833333 2294 166667 187 5 32 404 1666667 1920 833333 3654 166667 345 8333333 1454 166667 2720 833333 187 5 64 510 8333333 2774 166667 5360 833333 399 166667 1880 833333 3574 166667 187 5 100 630 8333333 3734 166667 7280 833333 459 166667 2360 833333 4534 166667 187 5 31006929 8 2007 449 Gateway Performance Serial Devices with 200 ms Response Time 10000 9000 8000 Time ms 6 6 40 60 Numbe
166. 60 116 216 384 31006929 8 2007 I O Scanner Performance TSXP575634M The TSXP575634M CPU used for the following measurements is at version 2 0 and CPU witha the TSXETY5103 Ethernet communications module is at version 3 1 TSXETY5103 Module baht 200 g 150 4 o 100 4 1 16 devices 50 J 0 4 1 r 0 50 100 150 PLC Scan Time ms 200 The bottom curve shows that the response times for 1 to 16 devices are within 1 to 4 ms of each other The response times for 32 devices are 6 to 9 ms longer The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from PLC Memory to Scanned Device Output ms TSXP575634M v2 0 10 ms 20 ms 50 ms 100ms_ 200 ms ETY5103 v3 1 Scan Scan Scan Scan Scan 1 device 13 23 53 104 205 8 devices 13 23 53 104 205 16 devices 14 24 54 104 206 32 devices6 20 31 61 111 211 31006929 8 2007 385 I O Scanner Performance TSXP57304M The TSXP57304M CPU used for the following measurements is at version 2 0 and CPU witha the TSXETY5103 Ethernet communications module is at version 3 1 TSXETY5103 Module 250 200 4 T 1504 E 100 4 71 s 16 devices 50 4 0 r r 1 r 0 50 100 150 200 PLC Scan Time ms The bottom curve shows that the response times for 1 to 16 devices are identical The response times for 32 dev
167. 6667 5653 67 172 32 2185 33 4401 996667 6935 33 2178 67 3987 003333 6053 67 172 64 2185 33 5148 663333 8535 33 2178 67 4360 336667 6853 67 172 100 2185 33 5988 663333 10335 33 2178 67 4780 336667 7753 67 172 466 31006929 8 2007 Gateway Performance Serial Devices with 500 ms Response Time Time ms 16000 14000 4 12000 10000 4 8000 6000 4000 2000 r 40 Number of Regi sters r 80 The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 500 Timeout EGX400 Time to Complete All Requests 1000 ms 1 Retry Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 2185 33 5778 663333 9885 33 2178 67 5725 336667 9778 67 172 16 2185 33 6128 663333 10635 33 2178 67 5900 336667 10153 67 172 32 2185 33 6501 996667 11435 33 2178 67 6087 003333 10553 67 172 64 2185 33 7248 663333 13035 33 2178 67 6460 336667 11353 67 172 100 2185 33 8088 663333 14835 33 2178 67 6880 336667 12253 67 172 31006929 8 2007 467 Gateway Performance D 3 174CEV30020 Gateway Serial Server Response Time and Timeout Measurements At a Glance Overview The performance of serial devices with response times of 50
168. 6929 8 2007 427 Modbus Client Performance At a CPU Scan Time of 50 ms 35 30 m a id CPU Cycles 6 Communications Completed The table below shows the data points used to generate the graph represented above 8 10 2 14 PLC Scan ms Server Response Time ms 50 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 2 2 2 1 1 1 2 3 4 3 1 1 2 4 5 7 4 1 1 3 5 6 8 5 1 2 4 6 7 9 6 2 2 4 6 8 11 7 2 3 4 7 9 12 8 2 3 4 8 10 14 9 2 4 5 9 11 16 10 2 4 6 9 13 19 11 2 4 6 10 14 20 12 3 5 6 11 15 21 13 3 5 6 12 16 23 14 3 5 6 13 17 25 15 3 5 6 14 19 27 16 3 5 6 15 20 29 17 3 5 7 16 21 31 428 31006929 8 2007 Modbus Client Performance At a CPU Scan Time of 10 ms 140 120 100 80 60 CPU Cycles 40 20 The table below shows the data points used to generate the graph represented above 4 6 6 10 Communications Completed 12 14 16 18 PLC Scan ms Server Response Time ms 10 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 6 4 4 5 6 8 2 6 4 5 7 9 14 3 6 5 6 14 19 26 4 6 5 8 18 19 29 5 6 5 9 22 25 35 6 7 6 15 25 31 43 7 7 7 20 28 35 51 8 8 8 20 30 41 58 9 8 11 21 35 47 67 10 10 12 21 38 51 76 11 11 14 22 43 58 82 12 11 15 22 46 63 94 13 12 16 23
169. 70 ms 9 cycles 100 ms 13 cycles 48 10 ms 4 cycles 20 ms 8 cycles 50 ms 18 cycles 70 ms 24 cycles 100 ms 34 cycles 80 70 4 60 50 4 3 o 40 gt 6 T d4 O 20 4 10 0 T 15 20 25 Communications Completed A sampling of results in the chart follows Number of Requests Server Response Time CPU Cycles Needed To Complete 1 lt 1 20 ms 2 cycles 50 ms 3 cycles 70 ms 4 cycles 100 ms 6 cycles 2 70 ms 3 cycles 100 ms 4 cycles 416 31006929 8 2007 Modbus Client Performance Number of Requests Server Response Time CPU Cycles Needed To Complete 4 50 ms 4 cycles 8 20 ms 3 cycles 70 ms 5 cycles 100 ms 6 cycles 15 10 ms 3 cycles 20 ms 4 cycles 50 ms 7 cycles 70 ms 6 cycles 100 ms 8 cycles 22 lt 1 ms 3 cycles 20 ms 6 cycles 50 ms 9 cycles 70 ms 10 cycles 100 ms 14 cycles 35 10 20 ms 7 cycles 50 ms 17 cycles 70 ms 22 cycles 100 ms 31 cycles 48 20 ms 10 cycles 50 ms 37 cycles 70 ms 51 cycles 100 ms 73 cycles 31006929 8 2007 417 Modbus Client Performance at a CPU Scan Time of 10 ms 340 320 CPU Cycles 50 ms 40 100 ms aot ae 70 ms 20 ms 10 ms Communications Completed A sampling of results in the chart follows
170. 771x1 Ethernet communications module is at version 3 5 140NOE771x1 Module 800 700 4 600 4 500 400 300 Time ms 200 4 100 4 0 i T T T T 0 50 100 150 200 250 PLC Scan Time ms The curves above show that response times remain within 5 to 6 ms of each other whether 1 8 16 or 32 devices are used The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Scanned Device Output ms 140CPU43412A v2 0 10 ms 20 ms 50 ms 100 ms 200 ms NOE771x1 v3 5 Scan Scan Scan Scan Scan 1 device 41 73 179 358 665 8 devices 42 75 180 360 666 16 devices 44 77 182 361 668 32 devices 46 79 185 364 671 31006929 8 2007 391 I O Scanner Performance Quantum I O Scanner Response Tmes Remote Input to Local Output Measurement Setup The curves below illustrate the Quantum PLC response times when a signal is sent from a remote input module to a local output module in the PLC ee Response Time The signal is triggered by a Momentum input module with a response time of 2 ms scanned into the Quantum PLC at a repetition rate of 0 ms see p 174 copied to another internal variable within the PLC written to a local Quantum output module Results are plotted for 1 8 16 and 32 devices 392 31006929 8 2007 I O Scanner Performance
171. 802 3 and Ethernet II the internetwork layer is Ethernet 802 3 and Ethernet II the network interface layer is implemented with IP the transport layer comprises UDP and TCP the application layer comprises 10 Transparent Ready services OND Ethernet Il and Ethernet II is the product of a joint development effort by Xerox Intel and Digital It IEEE 802 3 was introduced to the market in 1982 A year later the IEEE released their 802 3 specification Functionally they are very similar but the way in which the two formats frame one of the data fields make them incompatible with one another Ethernet II and IEEE 802 3 refer only to the physical characteristics of the network e the way in which information accesses the network CSMA CD e how the network frames the data messages e the physical characteristics of the network itself its topology cable requirements connectors infrastructure and so on IEEE 802 3 and Ethernet II can coexist on the same physical cable and use the same signals The only difference between the two is the data format 31006929 8 2007 127 Planning and Layout A data frame can be pictured as a block in which information travels along the network wire vy Modbus P Ethernet Frame g 3 Gt E Q 1 application protocols 2 internet protocols 3 Ethernet Il or IEEE 802 3 4 Ethernet topology 5 access to network CSMA CD The Internet Industrial automation professi
172. 833333 694 1666667 4240 833333 8294 166667 187 5 16 750 8333333 4694 16667 9200 833333 719 1666667 4440 833333 8694 166667 187 5 32 804 1666667 5120 83333 10054 16667 745 8333333 4654 166667 9120 833333 187 5 64 910 8333333 5974 16667 11760 83333 799 1666667 5080 833333 9974 166667 187 5 100 1030 833333 6934 16667 13680 83333 859 1666667 5560 833333 10934 16667 187 5 31006929 8 2007 451 Gateway Performance EGX200 Serial Server Response Measurements with One Request Timeout Test Setup The following charts show the time it takes to get responses from a certain number of requests sent to devices connected on the serial side of the EGX200 gateway when the system experiences a failure of one communications request e g a disconnected serial device The failure results in a 1000 ms timeout of the initial request followed by one retry of the request Note One request failure increases the response times for all requests The performance is based on network baud rates of both 9600 and 19 200 and on the amount of data i e the number of registers requested The following legend describes the baud rate and number of requests sent as tracked in all four of the charts that follow Curve Number of Requests Baud Rate 1 16 9600 2 19 200 3 8 9600 4 19 200 5 1 9600 6 19 200 452 31006929 8 2007 Gate
173. A back up device configured in a SCADA system is beneficial only when the system can reliably change over to the backup device if the primary device fails The back up device must be continually monitored to make sure it is operational data from the back up device needs to be read periodically so that the SCADA knows the health of the back up at all times Monitoring helps by e alarming a back up failure while the primary is in use so the failure can be corrected before the back up is required e allowing the SCADA system to check the status of the backup before deciding to switch over If the primary fails and the SCADA system switches to a failed standby it may cause confusion among personnel as well as waste time and stop your application 294 31006929 8 2007 Services Overview SCADA in a Quantum Hot Standby System Summary Traditional Hot Standby System Hot standby systems were traditionally implemented to control critical remote I O in industrial automation environments As SCADA systems continue to develop and play a more important role in plant operation the role of a hot standby system has changed A hot standby system may be required to provide redundant operation of control networks and SCADA communications New hot standby control rules need to be defined In a traditional industrial automation system the single goal of a hot standby PLC was to control the plant via physically connected I O 1 T
174. An item is a variable of any PLC that can be accessed either by their address or by their symbol OFS groups are characterized as follows Several groups may be defined A group may involve several devices Each item in a group may have a different device address A group involves various communication devices and media Each item may refer to a different communication driver If a device can be accessed via several communication media it is possible to mix variables addressed via different media within one group The items comprising a group may be different It is possible to mix all types of objects managed by the OFS for example mixing words double words and floating points in one group All the items in the same group have the same update rate and deadbanding percentage 260 31006929 8 2007 Services Overview OFS Services Synchronous Services Synchronous services are used to e partially or completely read and write a group of items e periodically scan variables read polling that must be handled by the client application The term synchronous means that the client application that calls a read or write service is blocked for the time it takes to obtain a result The instruction that follows a synchronous read or write call in the code of the client application is executed only after all the communication requests corresponding to that call have been processed During a synchronous read operation OFS doe
175. C Ethernet TCP IP Rational databas Premium Web sefver ar Ld 31006929 8 2007 237 Services Overview Architecture Flexible Web HMI Solution Hybrid Architectures FactoryCast HMI Web servers can be integrated into e installations that require flexible and cost effective HMI solutions hybrid architectures that supplement conventional SCADA systems e architectures where direct links are required between automation systems and information management levels IT links FactoryCast HMI devices replace conventional HMI or SCADA solutions for architectures that require a flexible multi station HMI A FactoryCast HMI device provides a temporary remote control function over Internet or company networks Typical architectures may consist of e several PLCs networked on an Ethernet network with FactoryCast HMI Web server modules e one or more clients with a thin client interface equipped with a simple Web browser e arelational database in which FactoryCast HMI can archive data directly from the automation system FactoryCast HMI modules read PLC data and execute HMI services email interpreted calculations connections to relational databases updating Web pages at source in the PLC without affecting the PLC program or the CPU scan time This solution provides e areliable HMI application executed at source in a PLC e an integrated multi station interface and remote access that is easy
176. C 60654 1 Environment Operating Range Light Industrial 25 to 70 degrees C Heavy Industrial 25 to 70 degrees C 31006929 8 2007 71 Planning and Layout Other Environmental Factors Humidity Table UV Exposure Table Humidity and UV exposure can also affect cable performance The tables below show the acceptable humidity range by percentage for operation and the acceptable number of hours of UV exposure Environment Humidity Light Industrial 5 to 95 noncondensing Heavy Industrial 0 1 to 95 noncondensing Environment UV Exposure Light Industrial 3000 hr Heavy Industrial 6000 hr 72 31006929 8 2007 Planning and Layout Ingress Protection Requirement Introduction Ingress is the ability of solid foreign bodies such as dust water moisture and other pollutants to enter an industrial equipment enclosure Ingress protection refers to the ability of the enclosure to keep these objects out This requirement also includes keeping people away from moving parts within the enclosure Two types of regulations define ingress protection variables e degree of pollution e degree of protection Degree of Pollution such as moisture or dust on the surface of devices can reduce their Pollution insulation capability The IEC 1010 standard specifies different types of pollution environm
177. Ethernet system 347 Transparent Ready services 355 Web 363 twisted pair Ethernet copper cable 78 U UDP in the Transparent Ready model 129 unshielded twisted pair cable characteristics 79 UV exposure requirements 72 V vibration requirements 69 VijeoLook implementation of the OPC server 286 virtual circuits in an Ethernet system 64 virtual private network for remote system access 146 VLAN end stations in an Ethernet system 57 VPN security 152 VPN remote access 146 W wake up function in an OPC factory server operation 262 WAN devices access servers 65 CSU DSU hardware 66 ISDN terminal adapters 66 modems 66 routers 65 switches 65 watchdog back up for a SCADA system 294 to monitor remote communications in a Quantum system 300 Web troubleshooting 363 Web server service device support 229 dynamic pages 226 operation 226 remote configuration support 225 static pages 226 Web FactoryCast service selection 160 WEP security 152 wireless communications in an Ethernet system 58 wiring recommendations 100 write operations for I O scanning 171 556 31006929 8 2007
178. Ethernet Switch 499NES27100 ee Parameter 148 218 112 101 gt Schneider Automation Ethernet Switch 10 100 Mbps IP Address 148 218 112 101 Subnet Mask 255 255 255 0 Default Gateway 0 0 0 0 VLAN ID 0 all 0 IP Configuration lt LOCAL gt MAC Address 00 79 63 00 02 77 System Name Switch_Role_Name Note Set IP Configuration lt LOCAL gt to use manual settings APPLY changes the stare if the objects immediately and saves the state to Non Volatile Memory MAIN MENU APPLY Enter Agent IP address in decimal dot format e g 148 218 19 69 31006929 8 2007 247 Services Overview Telnet Security a Port Configuration Statistics Port 01 State lt Enable gt Link Up Port Statistics Transmitted Packets Received Packets Received Bytes Received Broadcasts Received Multicasts Received Fragments Detected CRCErrors Detected Collisions MAIN MENU APPLY Type in port number and press enter 148 218 112 101 Schneider Automation Ethernet Switch 10 100 Mbps Port Name Set Speed lt autonegotiate Actual Speed 100MFDX Type 10 100 TP 277234 1231027 154371683 917923 183637 0 0 0 REFRESH sy The Telnet protocol implements a username and password that the client must use to gain access to the Telnet session In some cases the Telnet servers implement different usernames passwords for access to different device configuration o
179. FTP can be implemented in simple devices During a TFTP connection files are transferred between the client and the server The recipient of the file issues a confirmation that the file was received without errors The protocol does not permit retransmission of only part of a file that contains an error the entire file must be retransmitted This can represent a delay in the transmission time However the probability of errors in the file due to transmission or transmission loss is not very high As with the FTP service in Transparent Ready devices see p 243 TFTP uses are device dependent For example on a Modbus serial to Modbus Ethernet bridge the firmware is transferred using TFTP but the device configuration file cannot be To establish a connection with the server a client such as WSFTP or Windows TFTP client is required 246 31006929 8 2007 Services Overview Telnet Service Telnet Service The Telnet protocol provides an interactive text based communications session or Summary user interface between a client and a host Telnet interfaces can be used for tasks such as device configuration diagnostics and file interchange The Telnet protocol runs over the TCP transport layer using port 23 A Telnet session can generate unexpected amounts of network overhead because each keystroke may be sent as a separate TCP packet Here are examples of a configuration screen and a diagnostics screen for the ConneXium
180. IEC these existing standards can be used as references until ISO IEC 24702 is 11801 published The ISO IEC 11801 standard includes the following information Topic Chapter Description Clause Structure of the 5 Describes the functional elements of a generic cabling generic cabling system campus distributor building distributor transition system point etc and how they are connected together Implementation 6 Specifies a cabling design that when properly installed conforms to the requirements of the International Standard This section also defines maximum lengths Permanent link 7 Defines the permanent link and channel performance and channel requirements of installed generic cabling systems The specifications section defines the e Performance specifications of cabling for individual permanent links and channels e Performance specifications for two different media types balanced cables and optical fiber e Permanent channels and links and their classifications 5 classes class D being an application of up to 100 MHz e Performance specifications for the link channel based on the application performance around impedance return loss attenuation etc Cable 8 Provides the requirements for cable used in horizontal and requirements backbone cabling subsystems Connecting 9 Provides guidelines and requirements for connecting hardware hardware used in generic cabling systems requirements Shielding practices 10 Provides basic in
181. Number of Registers 80 100 The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 500 EGX200 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 685 3333333 4278 666667 8385 333333 678 6666667 4225 333333 8278 666667 172 16 735 3333333 4678 666667 9185 333333 703 6666667 4425 333333 8678 666667 172 32 788 6666667 5105 333333 10038 66667 730 3333333 4638 666667 9105 333333 172 64 895 3333333 5958 666667 11745 33333 783 6666667 5065 333333 9958 666667 172 100 1015 333333 6918 666667 13665 33333 843 6666667 5545 333333 10918 66667 172 462 31006929 8 2007 Gateway Performance EGX400 Serial Server Response Measurements with One Request Timeout Test Setup The following charts show the time it takes to get responses from a certain number of requests sent to devices connected on the serial side of the EGX400 gateway when the system experiences a failure of one communications request e g a disconnected serial device The failure results in a 1000 ms timeout of the initial request followed by one retry of the request Note One request failure increases the response times for all requests The performance is based on network bau
182. OPC servers vary in their abilities to enable disable variables and groups or add remove variables from a group OPC servers may or may not be able to block data for requests when the data is in multiple groups When the timing is set up for the polling of groups make sure that the polling does not overload the field devices The most common method used to poll data is to set a polling period that each group uses to read data If this period is set to 1000 the group tries to poll all the data every 1000 ms A problem can occur when multiple groups are set at the same polling rate When the 1000 ms time expires the SCADA system tries to read several blocks of data from the field devices causing spikes in the network and field device loads After these requests are answered the field device waits passively until the next time it is polled Depending on the field device this overload may cause communication failure or delays If the device is able to buffer requests and answer them over time and if the total average load is less than the device capabilities then the only problem is the small delay in answering the request Time SCADA Device Requests 100ms f Responses Doing T Nothing 500 ms y ete Requests To avoid this type of communications overload set the polling periods of the groups to unique values These values should be chosen so that the polling of multiple groups does not occur
183. One Request Timeout nanunua naana 452 EGX400 Gateway Serial Server Response Time and Timeout Measurements 0 000 cece eee eee 457 EGX400 Gateway Serial Server Response Times 20 00005 458 EGX400 Serial Server Response Measurements with One Request Timeout 0 c eee teas 463 174CEV30020 Gateway Serial Server Response Time and Timeout Measurements sanaaa cet teens 468 174CEV30020 Gateway Serial Server Response Times 469 174CEV30020 Serial Server Response Measurements with One Request Timeout nananana anaana 474 Standards and Other Considerations for Industrial Ethernet Networks 0000 0e ee eeeee 479 Standards and Organizations 0 000 cece tte 480 Electromagnetic Compatibility 0 0 cece eee 489 Copper Connector Standards Activities 00 0 0 eee eee 493 Conforming to Standards 0 0 cect teens 494 Transparent Ready Industrial Ethernet Conformance 5 496 Earthing Grounding Procedures 00 00085 499 Well made Earthing Ground Connections 000 cee eee eee 500 Making an Earthing Connection 000 c eee eee eee 501 Cable Shielding Connection Options 00 00 cee eee eee 507 Copper Ethernet Testing Procedures 0 000 cece 509 Performance ParameterS 0 00 nanan eet teeta 510 Definitions of Performance Parameters 0 0000 eee eee eee eee
184. PU scan If the maximum number of Modbus client requests exceeds the limits of the system the additional Modbus messaging requests are placed in a queue Each time the requesting function is evaluated by the CPU a check is made to see if the number of requests waiting on a response from the server is less than the maximum supported for the system If this is true the next request from the queue is sent to the server The Modbus client response time is response time number of requests in the queue x Modbus server response time for each request 1 CPU scan Modbus server response time to the new request 1 CPU scan 326 31006929 8 2007 Services Overview Premium PLC System Momentum PLC System For a Premium system the Modbus messaging request is sent at the end of the CPU scan current after the function inside the user logic is triggered When the response is received from the Modbus server that response is processed in the user logic memory the next time the calling function is processed This is normally during the CPU scan immediately after the PLC system has received the message Time CPU ETY Scan L Request block triggered Request sent to server gt lq Response Request sent to ETY Scan Request block processed v For a Premium system the response time is response time 1 CPU scan server response time 1 CPU scan If the maximum number of Modbus client requests
185. Planning and Layout Structured Cabling Standards Introduction Elements of a Cabling System Cabling Subsystems Schneider Electric recommends the use of structured cabling standards including TIAEIA 568B ISO IEC 11801 and CENELEC EN 50173 see p 32 Standards for cabling are currently being developed by a working group of the standards organizations The table below shows the elements of a cabling system as defined by the ISO IEC 11801 standard This standard also identifies the interfaces through which different network components are connected to the cabling system Elements Abbreviation Purpose Hierarchical Order Campus Distributor CD distributor from which the campus backbone cable emanates Campus Backbone Cable cabling between buildings that share telecommunications facilities Building Distributor BD the distributor where the bldg backbone cable terminates connections to campus backbone cable are made Building Backbone Cable intermediate cable amp connecting hardware Floor Distributor FD connects the horizontal cable system to other cabling subsystems Horizontal Cable cabling between and including the telecommunications outlet and the horizontal distributor Transition Point optional TP location in horizontal cabling subsystem where flat undercarpet cabling connects to round cabling Telecommunications Outlet TO female telecommunications device found in the
186. Refer to the information on the OSI see p 124 model Ethernet networks that require higher transmission speeds may use the fast Ethernet standard IEEE 802 3u which raises the Ethernet speed limit from 10 to 100 Mbps with only minimal changes to the cabling The fast Ethernet 100Base TX has become the most popular standard because it is very compatible with the existing Ethernet 10Base T Gigabit Ethernet 1000 Mbps is a technology under development IEEE 802 3z that may allow the next generation of networks to support even higher data transfer speeds The network sends data in units called frames also called data frames or packets Each frame can carry between 46 and 1500 bytes of data A frame includes protocol information for proper routing 31006929 8 2007 55 Planning and Layout Ethernet and Collisions Switched Networks and Collision Domains Network Congestion Because Ethernet allows multiple devices to exchange data simultaneously collisions can occur when two devices transmit data at the same time When this happens both devices stop transmitting and use a random back off algorithm to wait a certain amount of time before attempting to transmit the data again End Device A sent packet sent packet WM Collision tenp End Device B H Collisions can be managed by careful network planning and design The following design and operation factors may affect the collision rate of an Ethern
187. SXP571xx TSXP572xx TSXP573xx TSXP574xx Message Transactions s 60 450 500 350 350 Scanning I O Polling 2000 2000 2000 2000 Transactions s Global Data Subscription 800 800 800 800 Transactions s 31006929 8 2007 331 Services Overview System Performance Solutions Summary Problem 1 Problem 2 Problem 3 Here are several situations presented as problems and answers that may help when evaluating your own system s performance Problem A single SCADA polling a Quantum PLC with an NOE module sends 15 separate requests to read blocks of Modbus 4x registers All these requests are sent simultaneously How long does it take to complete all transactions when the CPU scan time is 50 ms Answer The NOE module can service 8 Modbus TCP requests per PLC cycle 15 requests take 15 8 2 PLC cycles All the requests are answered in 100 ms Problem A Premium PLC is reading data from a field device and writing the data to another field device The input field device has a response time of 80 ms and has already processed the input to its memory The output field device has a response time of 30 ms and the CPU scan time is 70 ms What is the response time i e from when the PLC reads the field input to when the new field output turns on Answer If the Premium PLC triggers a read request at the start of the CPU scan there is a delay of one CPU scan 70 ms before the request is sent The field devic
188. Schneider Electric suggests that you follow the guidelines that are defined in this chapter 31006929 8 2007 31 Planning and Layout Required Standards for Planning and Installation Ethernet Standards The Ethernet standard to consider when you plan an industrial Ethernet network is the one defined by the IEEE and adopted by ISO IEC IEEE standard 802 3 2002 Edition Part 3 Carrier sense multiple access with collision detection CSMA CD access method and physical layer specifications IEEE 802 3 Information Technology Telecommunication and Information exchange between systems Part 3 Carrier sense multiple access with collision detection CSMA CD ISO IEC 8802 3 IT Structured Cabling Standards Cable manufacturers suppliers building designers network architects and service technicians all rely on cable standards to provide the specifications for their projects These specifications include all aspects of the planning design and installation phases as well as the configuration performance conformance testing and verification of the final system The three major world standards shown in the table below are the foundations for cabling planning selection installation and performance of IT networks Each standard in the table is based on the one that precedes it As a result all of the standards are very similar Area and Standard Standards Organizations Description
189. Standards for Fiber Optic Cable Fiber Optic Cable Technical Description Fiber optic cabling offers an alternative to copper wiring replacing traditional UTP and STP cable Typically fiber optic cable is used for backbone networks in buildings and campuses Improvements in fiber optic performance connectivity and testing make it the best choice for LAN connections across long distances as for example between manufacturing plants or industrial facilities Additional advancements in transceiver products and lower cable costs add to its attraction as a high performance option The existing TIA EIA fiber optics standards do not define an architecture like the TIA EIA 568 B and ISO IEC 11801 standards Instead the fiber optic standards are written to apply to all fiber installations regardless of their location or use Today the same standards apply to all installations there are no distinctions made for fiber cable suspended under water or in the air inside or outside a building used for backbone networks or installed in airplanes Fiber optic cable uses long thin strands of ultra pure glass silica or plastic that transmit light signals over long distances The glass strands are very thin about the size of a human hair and are arranged in bundles called optical cables A fiber optic cable consists of a center glass core surrounded by glass cladding and a plastic jacket Light photons are transmitted through the center core a
190. TY module 12 The ETY module is limited to 400 transactions s for all modules The embedded Ethernet port is limited to 500 transactions s on the Unity CoPro systems 192 31006929 8 2007 Services Overview Premium Modbus Server Operation Premium Response Times The response process for Premium systems functions as follows Sequence Event 1 The Modbus client establishes a TCP socket to the ETY module or embedded Ethernet port The Modbus client sends a request along the TCP socket The ETY module or embedded Ethernet port receives the request and may acknowledge it The request is placed in the ETY module embedded Ethernet port queue At the beginning of the next CPU scan the ETY module embedded Ethernet port passes requests to the CPU At this time all communication modules pass requests to the CPU including Fipway Ethway and SCP serial modules The CPU answers as many requests as possible the limit is determined by the CPU If more requests are received than can be answered the CPU responds with a Modbus busy exception to the ETY module embedded Ethernet port which sends the exception response back to the clients The ETY module embedded Ethernet port receives responses to all answered requests and sends responses back to the clients The TCP socket is left open The Premium response time is the time period between receiving a
191. The chapters may be read in any order based on the topics that interest you the most Physical Planning Design and Installation of a Transparent Ready Industrial Ethernet Network p 27 describes how to design install and verify your Transparent Ready industrial Ethernet network to best meet your application requirements including the following considerations design standards choice of cabling and components Internet technology overview environmental requirements protective earthing recommendations testing your network IP Addressing routing security Services Overview p 153 describes each of the Transparent Ready services the appropriate device choices for each and the Transparent Ready devices that support each service Service support is a very important device selection criterion Choosing the right services enables you to account for the following system design issues e appropriate device response times e avoidance of device overload e application throughput requirements for the entire system This chapter also explains how the different services operate and their expected performance 24 31006929 8 2007 Transparent Ready Trouble shooting Supporting Information Troubleshooting p 341 provides procedures for how to maintain a Transparent Ready system after installation These procedures include how to e identify problems such as e network infrastructure issues e device incompatibility
192. The tool marks each packet with the exact time so you can find specific packets at the time of the error Note that packets showing the problem are usually seen just before SCADA reports the error because of timeout and reporting delays filter the captured data to just the required packets Use data filtering to find the packets you want to investigate Filter packets with one of two methods during the capture stage Filtering during capture can discard packets that are needed for analysis later If that happens you have to do another capture in the stored data This is the suggested method Filter according to address IP or MAC and protocol destination socket number Then filter the visible data to a single TCP socket based on source socket number 31006929 8 2007 369 Troubleshooting 370 31006929 8 2007 Appendices What s in this Appendix The appendix contains the following chapters Chapter Chapter Name Page A I O Scanning Response Times 373 B Modbus Server Throughput Capacity 401 Cc Modbus Client Response Times 405 D Gateway Response Time and Timeout Measurements 445 E Standards and Other Considerations for Industrial Ethernet 479 Networks F Earthing Grounding Procedures 499 31006929 8 2007 371 Appendices 372 31006929 8 2007 I O Scanning Response Times A At a Glance Overview What s in this C
193. Use optical fiber cable for data links between buildings in any Transparent Ready application A fiber link eliminates loop problems between buildings 104 31006929 8 2007 Planning and Layout Ethernet Copper Cable Types Ethernet Cables You can make two types of Ethernet cable straight cable or crossover cable Straight Cable Ethernet infrastructure devices such as switches and hubs are always located between two end devices Typically these infrastructure devices cross the signal and therefore the cable between the end device and the hub or switch must be a straight cable Straight Cable The EIA TIA 568B and IEEE 802 3u standards define the pinout for an Ethernet Pinout straight cable as shown in the diagram below Q TX TX TX TX RX RX RX RX 1 end device 2 intermediary device 3 straight cable The RJ45 pinout connection from an end device to an intermediary device uses straight cables that follow the color code and signal specifications see p 80 Signal l l Sig gnal shine in jack end device RJ45 Pin RJ45 Pin in jack intermediary device TX 1 Inn q RX TX l 2 ee 2 ne l TX AKE 3 Cocoon 3 Unused 4 4 Unused Unused 5 7 Unused RX iil o UR Unused l 7 nonrnnannnrnninnonn 7 Unused Unused l a Unused End Device l Straight Cable Intermediate Device I 1 orange striped
194. V New input New output End of CPU New request New request Output at I O available ready scan sent at field device CPU communications adapter For a configured repetition rate of 0 ms the formula for the worst case time is e total time Tmod 1 CPU scan if T1 gt 1 CPU scan then T1 1 CPU scan Else 1 CPU scan 1 CPU scan 0 3 ms no Requests Tmod e T1 0 3 ms number of requests device response time 31006929 8 2007 177 Services Overview The following chart illustrates a Premium I O scanner s performance round trip from the field input to the CPU and back to the output Delay in Field 1 Rep Rate Delay Sending Delay in Field Device New Requests Device A ge ge vies 2 Gee ed New Field Input Available in New Request New Request Response Start of next CPU Input Communications Sent at Field back at PLC Scan Response Adapter Device taken into CPI Possible 1 scan Delay Sending Delay in Field TCEU SCAN Delay 1 Rep Rate New Requests Device New Input New Output End of CPU Output in New Request New Request Output at I O Available Ready Scan ETY Module Sent at Field Device CPU Communications Adapter For a repetition rate of 0 ms the formula for the worst case time is e total time Tmod T1 1 CPU scan 1 CPU scan 1 CPU scan for ETY only 0 3 ms number of requests Tmod e T1 0 3 ms number of requests device response time The following chart illustrates the typical I O scanner
195. Web pages These Web pages may be created with standard HTML editing tools such as Microsoft FrontPage and Macromedia Dreamweaver Java applets linked to PLC variables can enhance these pages by providing graphical representations of plant status These animated objects are provided in the graphic data editor supplied with FactoryCast The Web pages can be used to e display and modify variables in real time e create hyperlinks to other external Web servers The graphic data editor lets you create graphical screens for display monitoring and diagnostics generation of real time production reports maintenance manuals operator guides The MS Windows based configuration software for FactoryCast Web servers is supplied on CD ROM with every FactoryCast module Use the software to configure and administer the Web server embedded in these modules It allows you to access security management define user names and passwords for accessing Web pages define access to variables authorized for modification save restore an entire Website transfer Web pages created locally to and from the FactoryCast module 31006929 8 2007 231 Services Overview FactoryCastWeb Your ability to configure plant diagnostics makes important information readily Server Uses available and lays it out in a format you choose You can create Web pages that contain manuals operating procedures and useful reference material such as CAD drawings If t
196. XETY5103 X OK X OK OK XxX OK OK x Xx TSX Micro TSXETZ410 TSXETZ510 Momentum 171ENT11001 Advantys STB STBNIP2212 Altivar ATV38 58 VW3A58310 XxX XxX KL Xx Xx 31006929 8 2007 207 Services Overview 3 6 Time Synchronization At a Glance Overview This section describes the time synchronization service and how it distributes time to devices on the network What s in this This section contains the following topics ion Section Topic Page Time Synchronization Service 209 Time Synchronization Service Operation 211 Time Synchronization Applications 212 Schneider Devices Implementing Time Synchronization Service 216 208 31006929 8 2007 Services Overview Time Synchronization Service Time Synchroni Time synchronization is a service that distributes and maintains an accurate time for zation Summary devices on the network Typically the time is accurate to within 1 to 2 ms After the devices have been time synchronized this service can be used to e synchronize an action e time stamp the occurrence of events Sequence of events recording e manage the order of plant operations Time synchronization is achieved by sending out periodic time updates to all the devices configured for this service 1 GPS satellite time 2 NTP time servers 3 local time 31006929 8 2007 209
197. a points used to generate the graph represented above PLC Scan ms Server Response Time ms 50 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 2 2 2 1 1 1 2 3 3 3 1 1 3 4 4 5 4 1 1 3 5 6 7 5 1 2 4 6 7 8 6 2 2 5 6 8 9 7 2 3 5 6 10 12 8 2 3 5 6 12 13 9 2 4 5 8 14 15 10 2 5 6 9 16 17 11 3 5 6 10 17 18 12 3 5 6 10 19 20 13 3 5 6 11 19 22 14 3 5 6 12 21 24 15 3 5 6 13 23 25 16 3 5 6 13 24 27 17 3 5 6 15 25 28 31006929 8 2007 443 Modbus Client Performance At a CPU Scan Time of 10 ms 140 7 120 4 100 80 4 60 5 CPU Cycles 40 5 20 Communications Completed The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 10 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 4 4 4 4 5 6 2 4 4 5 7 8 10 3 4 7 6 18 18 20 4 5 8 8 18 19 26 5 6 8 10 19 20 30 6 6 11 12 19 24 34 7 7 16 18 21 28 41 8 7 18 18 26 31 46 9 8 19 20 30 39 55 10 9 19 21 33 42 64 11 9 20 21 34 46 69 12 10 20 21 39 52 76 13 10 21 22 42 57 83 14 11 23 24 47 63 91 15 11 24 24 51 68 96 16 12 24 25 55 74 106 17 13 24 26 57 79 115 444 31006929 8 2007 Gateway Response Time and Timeout Measurements
198. a specific elementary function block NTP Server Power Supply Processor Ethernet Module NTP Request Internal Ethernet Network Clock NTP Response Premium Quantum 31006929 8 2007 211 Services Overview Time Synchronization Applications Functions that Time synchronization gives all devices on the network the identical time reference Use Time This service supports event time stamping alarms and program or file changes Synchronization across the plant based on the same time PLC clocks synchronized 212 31006929 8 2007 Services Overview Sequence of To time stamp events the PLC must be able to detect an event as it occurs at the events I O module To do this choose a module with minimal filtering and delay times If Recording possible link the input module to an event task in the CPU a feature supported on higher end CPUs The field event is detected by the module and calls the event task interrupting the program and allowing the application code to time stamp the input If the CPU does not support the implementation of event tasks the fast task should be used Configure the fast task to execute as frequently as possible Unlike the event task the fast task interrupts the execution of the main program to check for events Fast task execution frequency should be configured so it does not heavily impact the execution time of the main program The
199. a specific amount of time Modbus Server c amp O a gt 2 5 1 retrieved data 2 client request 3 server response 4 data retrieval A device may implement a Modbus client service a Modbus server service or both depending on the requirements of the device A client is able to initiate Modbus messaging requests to one or more servers The server responds to requests received from one or more clients A typical HMI or SCADA application implements a client service to initiate communications with PLCs and other devices for information gathering An I O device implements a server service so that other devices can read and write its I O values Because the device does not need to initiate communications it does not implement a client service 31006929 8 2007 181 Services Overview What a Modbus Client Service Provides What a Modbus Server Service Provides Modbus Function Codes A PLC implements both client and server services so that it can initiate communications to other PLCs and I O devices and respond to requests from other PLCs SCADA HMls and other devices Glen Client A device that implements the Modbus client service can initiate Modbus messaging requests to another device that implements a Modbus server These requests allow the client to retrieve data from or send commands to the remote de
200. able Types Multimode Cable Multimode fiber has a large core diameter about 2 5 x 10 3 in or 62 5 um and transmits infrared light wavelength 850 to 1300 nm from light emitting diodes LEDs Multimode fiber cable is most often used in LED based LAN systems campus networks and short distance metropolitan networks There are two types of multimode cable e Step index has an abrupt change between core and cladding is limited to about 50Mb s e Graded index has a gradual change between core and cladding is limited to 1Gb s Note The core specifications for step index and graded index multimode cables are typically 50 60 5 or 100 um The cladding diameter for step index cable is 125 um When cable is graded the amount of refraction is reduced gradually outward from the core Because light travels faster when refraction is lower light travelling through the outer material travels faster than light at the center of the core The following illustration shows step index multimode graded index multimode and single mode cable High order mode Dispersion amt Multimode Low order mode Dispersion gt lt Graded index Multimode Single mode 84 31006929 8 2007 Planning and Layout Fiber Cable Types Single Mode Cable Advantages of Single vs Multimode Advantages of Fiber Optic V
201. able for the remote devices You may be able to do an initial write to the remote device to configure it if this is supported by the remote device However you need to disable that entry after the initial configuration because you don t want the write request to take place at every configured repetitive rate The I O scanner device does not have any specific information about the remote device other than its IP address Due to this open system you have no control over the remote device s response time WIth other I O systems you are able to determine the cyclic time at which the information is expected With I O scanner there is no set value as to when that register data exchange takes place It may be different for each remote device 31006929 8 2007 167 Services Overview Remote Device I O Scanning Requirements Applications Some other characteristics of I O scanner are e maximum transferable data block sizes of 100 words written and 125 words read per entry e maximum number of words read or written is 4 000 e multiple data blocks that can be exchanged with a single remote device e auser configurable repetitive data transfer rate see p 174 ranging from 1 ms to 5s e fault reporting for each remote device e adata exchange enable disable for each remote device Each entry in the I O scanner configuration creates a new socket including multiple entries to the same remote device e Modbus TCP IP messaging sup
202. adds new concepts such as the classification environment as presented below in the MICE table suitable components and a modified cabling structure 31006929 8 2007 29 Planning and Layout MICE Concept Mechanical Rating The IEC TC65C working group originated the MICE concept of mechanical rating to define environmental parameters and their requirements MICE includes three environmental classes e Class 1 for general non industrial non residential e Class 2 for light industrial e Class 3 for heavy industrial It also defines the environmental parameters on which its name is based mechanical ingress climatic electromagnetic Each environmental parameter has a low level 1 medium level 2 and high level 3 rating that is indicated in subscript beside each parameter s letter for example MoloC3E As you can see from this example parameter levels may be mixed and may vary along a single channel Each environmental class has a worst case scenario as given below e M 1 C E for a general ISO IEC 11801 environment e MoloC gt Ez for a light industrial environment e Mg3lgC3E3 for a heavy industrial environment The MICE table is shown below gt Increasing Severity gt Class Mechanical Shock Bump M M2 M3 Vibration Tensile Force Crush Impact Ingress Particulate l4 Ip l3 Immersion Climatic Temperature Cy Cy C3 Ambient Rate of Change
203. ail Note You may implement a hot standby system for communications purposes only Such a system is not required to control physical plant I O A dummy I O rack must be configured and the RIO network needs to be physically installed to allow the hot standby system to operate The following illustration shows a redundant SCADA system with hot standby PLCs SCADA monitoring a critical process controlled by the PLC Critical intelligent devices controlled via Ethernet by the PLC The primary CPU The standby CPU Racks of remote I O modules AUN The original industrial automation priorities of the hot standby system which provide redundancy for the remote I O remain the same In addition you can assign equal or even greater hot standby priority to the plants communication link Although the Quantum hot standby system was originally designed principally for I O control full user control of the changeover capability is provided You can customize the operation so that communications failures at the plant level trigger a primary standby changeover You can program your system to switch control if the current primary CPU loses communications with the SCADA platforms or with the critical Ethernet devices even if there are no communication problems between the CPU and the remote I O 296 31006929 8 2007 Services Overview Rules for a Communication centric Hot Standby System Basic Redu
204. al Output 392 Quantum I O Scanner Response Times Local Input to Remote Output 396 Modbus Server Throughput Capacity 401 Quantum Modbus Server Throughput Capacity Unity v2 0 402 Premium Modbus Server Throughput Capacity Unity v2 0 404 Modbus Client Response Times 002e0ee00e 405 Modbus Client Response Times Premium TSXP575634M 406 Modbus Client Response Times Premium TSXP57304M 413 Modbus Client Response Times Quantum 140 CPU65150 with an Embedded Ethernet Port 0 2 02 c eee eee 420 Modbus Client Response Times Quantum 140 CPU65150 with a 140 NOE77101 Ethernet Communications Module 425 Modbus Client Response Times Quantum 140 CPU65150 with a 140 NOE77111 Ethernet Communications Module 430 Appendix D D 1 D 2 D 3 Appendix E Appendix F Modbus Client Response Times Quantum 140 CPU43412A with a 140 NOE77101 Ethernet Communications Module 005 435 Modbus Client Response Times Quantum 140 CPU43412A with a 140 NOE77111 Ethernet Communications Module 005 440 Gateway Response Time and Timeout Measurements 445 EGX200 Gateway Serial Server Response Time and Timeout Measurements 00 000 tee 446 EGX200 Serial Server Response TimeS 0 0 0c eee e eee eee 447 EGX200 Serial Server Response Measurements with
205. al layout and environmental variables inherent in each of these facilities may result in different requirements for the cabling system at each site This section describes Schneider Electric s recommendations for planning industrial Ethernet networks for manufacturing and process control environments Cable Planning A network site plan communicates the physical and logical layout of a network that is specific to your site requirements This plan is an important part of the network design process for your facility The site may be an industrial facility or an infrastructure site Infrastructure sites include environments such as tunnels water treatment plants and airports with additional requirements to those of an industrial site Both types of site have environmental variables that may be extreme compared to office environments The existing standards for office environments though useful and valid have limited application in such environments Application performance under rigorous environmental requirements including climatic conditions and ingress protection has a higher priority in an industrial environment The following topics provide general information on planning an industrial Ethernet network for industrial and infrastructure applications This information does not attempt to cover every possible variation of these two environments You should adapt this information to the specific needs of your site 31006929 8 2007 35
206. an leased or private lines e point to point VPN VPN technology can also be used to connect remote sites or branch offices to the organization s main network VPNs are replacing such WAN technologies see p 62 as leased lines frame relay and ATM A VPN provides traditional WAN requirements for this situation such as multi protocol support high availability scalability and security As mentioned above it also has advantages over private WAN services 146 31006929 8 2007 Planning and Layout PLC Connected to the Internet Summary Permanently connecting a PLC to the Internet can be costly and difficult for a small company or OEM However for a large company that already has a permanent Internet connection and is familiar with such issues as hosting its own web servers the task is simply an extension of their existing system Internet This system offers several benefits over the previous RAS setup Connection Benefits Disadvantages e The PLC is permanently connected to the Internet This allows quick access to the PLC from any PC connected to the Internet no modem required e No long distance phone calls are required to access the PLC simply connect to your local ISP e The number of simultaneous remote connections to the PLC is not limited by the number of modems on the RAS server However there are some serious disadvantages and difficulties e A permanent connection to the Internet is required e A pe
207. anCe si in5 2 sare akai x w a a a della do E Eaa dean dees 264 Runtime Architecture for Unity OFS SCADA a Simple Example 267 Build time Runtime Architecture for Unity OFS SCADA Systems that Are Not Frequently Modified 0 0 eee eee ees 268 Build time Runtime Architecture for Unity OFS SCADA Systems that Require Frequent Modification 0000 0c eee ee 270 Build time Runtime Architecture for a System with Multiple SCADA GonnectionSes 2 gsncnie ccawededeatend Revel ee OSA A es oe 272 SCADA AMIS ors cede euen e vere hc ch a a EE E T tna gene or neta Serta EISA 274 I O Server to Field Device Communications 000 cece eee 277 SCADA Communications to Field Devices Socket and Request Usage 281 I O Server and Display Client Communications 2 55 285 Schneider Product Implementation Details 0 cece eee 286 Redundancy scree ccet dei aces ek Ge Soe Pe Be SEE RE te 287 Network Redundancy and Communication Services 288 Redundancy within a SCADA System 000 c eee eee 292 SCADA in a Quantum Hot Standby System 00 00 c eee eee 295 Hot Standby Swap and Ethernet Services 00000 eee eeee 302 Gateway Bridge Systems 0 0 0 cee eee 304 Gateway and Bridge Overview 00 cece eee eae 305 Gateway and Bridge Operation 0 0 cece eee eee 309 Supported Services per Device 00 ccc eee eee
208. and segment network properly For applications where minimum application downtime is required Use self healing ring or redundant self healing ring For networks that require basic level diagnostics e g no link or failure of one P S Use unmanaged switches with alarm relay For networks that require high level services and traffic administration Use managed switches For applications that require network discovery and monitoring Use managed switches For applications that require interconnecting devices separated by long distances gt 100 m Use fiber optic products Multimode fiber Up to 2 km between nodes Monomode fiber Up to 15 km between nodes Note Depending on the fiber and the optical budget could reach 4 km on multimode and 30 km on monomode For networks that require immunity to electromagnetic noise Use products with fiber optic ports For applications that require physical medium change Use transceivers or use switches with a combination of copper and fiber optic ports For applications that require external IP67 mounting of the switch Use IP67 switches and cables 92 31006929 8 2007 Planning and Layout 2 5 Installation At a Glance Overview This section describes measures you can take to prevent electromagnetic interference EMI from seriously impeding your network or from causing intermit
209. ansmission rate of 100 Mb s 200 Mb s in optional full duplex mode and the maximum segment length is 2000 m full duplex The typical cable is multimode 62 5 um fiber core with 125 um outer cladding 1300 nm wavelength For Transparent Ready industrial Ethernet applications Schneider recommends the use of 62 5 125 type fiber using the minimal amount and maximal quality of fiber Schneider supports communications on wavelengths from 850 nm for 10Base FL to 1300 nm for 100Base FX The cable may contain other fibers or electrical conductors The protection specifications for the cable must be compatible with your installation conditions Environment Physical Layer Recommended Wave Maximum Segment Fiber Length Length Light and Heavy 10Base FL 62 5 125 850 nm 2000 m Industrial multimode Environment 199Base FX 62 5 125 1300 nm 200 m full duplex multimode 86 31006929 8 2007 Planning and Layout Ethernet Connectors for Copper Networks Summary Recommended Ethernet Copper Connectors RJ45 Connector Shielded or Screened RJ45 Connector After a thorough analysis of market trends industry proposals and on going standardization work and in the absence of international standards for copper cabling in industrial Ethernet networks Schneider Electric has defined the types of connectors to use in Transparent Ready industrial Ethernet products as of this writing Sc
210. arameters and their Class D values for network links and channels Parameter Permanent Link Permanent Channel Class D Channel D Frequency it is presented 100 MHz 100 MHz at 100Mhz but needs to measure over the 1 100Mhz range Maximum Attenuation 20 6 dB 24 dB Minimum NEXT 29 3 dB 27 1 dB Minimum Power sum 26 3 dB 24 1 dB NEXT Minimum ACR 8 7 dB 3 1 dB Minimum Power sum ACR 5 7 dB 0 1 dB Minimum ELFEXT 19 6 dB 17 0 dB Minimum Power sum 17 0 dB 14 4 dB ELFEXT Minimum Return loss 17 dB 17 dB Maximum Propagation 489 6 ns 547 6 ns delay Maximum Delay skew 43 ns 50 ns Minimum Longitudinal to The measurement of these values The measurement of these differential conversion loss on installed systems is not yet values on installed systems well established It is sufficient to is not yet well established It verify the values by design is sufficient to verify the values by design Parameter Permanent Link Class D Maximum Loop resistance ohms 40 Q 516 31006929 8 2007 Glossary 100BaseT4 10Base F 10Base T 10Base2 10Base5 802 802 1 802 2 802 3 802 4 100 Mb s Ethernet running on four pairs of category 3 4 or 5 unshielded twisted pair cable 10 Mb s Ethernet running on optical fiber 1OBASE F is a point to point network medium e g hub switch device to station 10 Mb s Ethernet running o
211. ardware e network bandwidth Considerations resources of module or CPU with Ethernet embedded processor resources PLC PC or other CPUs Application e Modbus or Uni TE industrial messaging handling service Services e global data service data scanning between PLC e O scanning service data scanning of distributed I O e others Web access TCP open communication It may be difficult to determine the correct size of an architecture because most of these parameters are linked Response time is determined using the graphs in Appendices A through D showing the response times for sample systems or formula based calculations that can be used to calculate the response time for any system Modbus Messaging Response Times The Modbus messaging service involves the following components in a data transfer e Modbus client e network transfer e Modbus server These components are the same for all Modbus messaging systems To determine the response time of a Modbus system the timing for each of the above items needs to be calculated Each component can be calculated separately and the total response time determined 320 31006929 8 2007 Services Overview Modbus Server Response Times Summary Two methods can be used to determine the Modbus server response time e measured response times for general times for all devices e g PLCs and as the actual value for simple devices e g a VSD an I O block e calculation
212. asses the request from the queue to the CPU in one of two possible ways e f the NOE requests a Modbus register read write FC3 FC16 or FC23 it reads the PLC s memory by using request type 1 e f the NOE module requests any other Modbus function code it passes the entire request to the CPU for processing type 2 In the case of the embedded Ethernet port the request from the queue is passed to the CPU The NOE module embedded Ethernet port immediately receives an answer to any request except programming requests sent to the CPU The NOE module embedded Ethernet port sends the response back to the Modbus client 8 The TCP socket is left open e Path type 1 requests give the NOE module direct memory access e Path type 2 requests pass the entire Modbus message to the CPU 31006929 8 2007 189 Services Overview Depending on the system the NOE module or the embedded port may respond to a different number of requests at the end of each CPU scan The following diagram shows the five backplane paths between the NOE module and the CPU 4 Backplane Type 1 Paths FC3 FC16 and FC23 AAAA YYYY CPU NOE Module 1 Backplane Type 2 Path All other FCs A y Concept Each time the NOE module is serviced once per CPU scan it sends one request Proworx Modbus across each of the five paths The type 1 backplane paths allow direct memory Server Op
213. ation e the host node or end device information The IP address comprises 4 sets of decimal numbers called octets each separated by a period with a value from 0 to 255 that represents a converted binary to decimal number Classless addressing also known as CIDR or supernetting was developed to improve current Internet problems regarding the efficient utilization of address space It also is used to add to the routing scalability of networks Allocating portions of the large but limited number of addresses to an enterprise all at one time often resulted in the waste of some reserved addresses Including each network in a table resulted in overload Also medium sized enterprises that fit the class B category have multiplied the fastest using much of the space in that class Classless addressing by allowing the delineation point between network information and host information to be flexible has expanded the number of addresses available to all sizes of enterprise and has reduced the size of routing tables Public addresses for use on the Internet are assigned by a governing organization called the Internet Assigned Numbers Authority IANA However your company may already have been assigned a section of addresses and your IT person can allocate the quantity that you need If you have not been given a predefined set of IP ranges you should be aware that the following three blocks have been reserved by IANA for private Internets 10
214. aximum delay that can be supported without losing control of communications Propagation delay skew is the difference between the propagation delay on the fastest and slowest pairs in a UTP cable or cabling system Twisted pair cable signal transmission assumes that the signals on each wire relative to earth ground are balanced This means that anywhere along the length of the cable the signal on one wire of a twisted pair measured relative to earth ground is exactly equal in amplitude but exactly opposite in phase to the signal on the other wire of the same twisted pair If this ideal were true there would be no RF signal emitted from the pair no EMI RFI and coupling inside the link would be reduced The normal NEXT is the result of the coupling of a differential signal applied to one pair showing up as a differential mode signal at the receive input Other coupling mechanisms that occur when the signal is not applied in a purely differential manner include the differential mode to common mode coupling common mode to differential mode coupling and common mode to common mode coupling These coupling mechanisms can be significant sources of excess NEXT Therefore this parameter defines how well the signal applied by the tester is balanced as it enters the link 31006929 8 2007 515 Earthing Grounding Procedures Parameter Values for CAT5 Cable from ISO IEC 11801 The following table lists the specification p
215. based on system operation for more complex devices like Quantum or Premium PLC systems The measured response times for various Schneider Modbus server devices are described in an appendix see p 407 These response times were measured under controlled conditions and may vary from results obtained in the field These graphs are valid only if the overall limits of device communications are not exceeded The Modbus server response times for the following devices are not fixed and need to be calculated e Premium PLC system e Momentum PLC system e Quantum PLC system Premium PLC The PLC system response time for all received Modbus messaging requests is System equal to one CPU scan time All Modbus messaging requests received during the CPU scan are answered before the start of the next scan If the total number of Modbus messaging requests received by the CPU in a single scan is greater than the limit for that type of CPU all additional requests are answered at the end of the same scan However all additional requests receive the Modbus exception response Server Busy instead of the actual data requested Time Client Server Syn gt Syn Ack lt Request m j Scan start Answer Request gt Request ea Scan start v 31006929 8 2007 321 Services Overview Momentum PLC The response time of a Momentum PLC system for all received Modbus messaging System requests is one CPU scan time All Modbus me
216. based on the accepted ISO IEC 11801 EN 501731 and TIA EIA 568B standards The following diagram shows a cabling system with the following parameters an industrial site distributor that acts as the central communication unit instead of a campus distributor see p 36 and connects plant distributors along an industrial site backbone plant distributors that connect office plant and plant floor distributors along a plant backbone plant floor distributors that connect to cabinet distributors CD also called machine or field distributors FD and the devices and device outlets DO inside the cabinet office plant distributors that connect to telecommunications outlets that are themselves connected to printers and computers It is important to understand that a site may have many plants within it The following example shows an overview of a grain site with 6 plants Industrial Site Administration Office Mixing Plant arwond Port Plant Shipping Plant Mill Crushing Plant Oil Extraction Plant Silo Plant SD Site distributor PD Plant distributor POD Plant office distributor PFD Plant floor distributor FW Firewall 40 31006929 8 2007 Planning and Layout Single Plant The following illustration is a closer view of a single grain plant within the site shown Example in the previous figure ay S m O a 4
217. be polled arrange the variables used for alarms and trending so they are adjacent to each other Items that are trended at the same rate should be grouped and alarms should be grouped An exception to the data blocking rule is unlocated variables Both the Unity and Concept software allow variables in the field device to exist without physical addresses A specific Modbus messaging function code can read write these variables The variables cannot be located next to each other but the SCADA system can read write them as efficiently as a block of located variables However some devices are able to answer requests for located variables faster or more often than for unlocated ones AXXX 280 31006929 8 2007 Services Overview SCADA Communications to Field Devices Socket and Request Usage Summary You need to consider several factors to determine how your SCADA system may transfer data to a field device how the data groups are structured when another section attempts to read the data groups TCP sockets and how they are used the number of Modbus messaging requests that can be sent down each socket the types of requests used A SCADA system can open one or more TCP sockets to a device It can send Modbus messaging requests on each of these sockets Depending on how the SCADA system is designed it may allow you to control the number of sockets to be opened and how the requests can be sent or it may only perform a
218. bout planning and installing a telecommunications network for commercial buildings 488 31006929 8 2007 Standards and Considerations Electromagnetic Compatibility Introduction Definitions Disturbance or Interference Electro magnetic Influence EMI can be an interfering electromagnetic noise unwanted signal or change in the propagation medium that can impair the performance of devices and equipment or of an entire system It is one of the main causes of malfunction for communication networks in industrial environments EMI can impact industrial applications in different ways ranging from acceptable influence to damaged system components During the installation process you need to recognize EMI conditions and follow procedures that support electromagnetic capability and a safe environment This following discussion provides basic information about the types and sources of EMI and proposes solutions that can reduce EMI in environments where industrial machines and communication networks must coexist Also included are the explanations of terminology and classifications EMC is the ability of a device equipment or system to function satisfactorily in its electromagnetic environment without introducing intolerable disturbances to that environment or to other equipment It requires that the interference emission level of equipment or devices in a system be low enough not to interfere with other equipment or device
219. bus client communication blocks instead of the I O scanner The client may report this error Otherwise you must either ascertain the number of sockets in use through analysis of the communications or use an Ethernet packet capture tool to see the socket rejection Intermittent additional devices Timeouts on the Ethernet side are not long enough They are less than communications fail after one fails the total timeouts on the serial side Refer to gateway section see failures p 304 for more information intermittent errors Timeouts on the Ethernet side are too close to the time required for gathering serial line data Refer to gateway section see p 304 for more information 31006929 8 2007 365 Troubleshooting 4 6 Lost Packet Troubleshooting At a Glance Introduction This section describes troubleshooting for lost data packets What s in this This section contains the following topics Section z Topic Page Lost Packet Troubleshooting 367 Using a Packet Capture Tool 368 Packet Capture Troubleshooting 369 366 31006929 8 2007 Troubleshooting Lost Packet Troubleshooting Problem Category Topic Cause and Actions General effect of a lost packet A lost packet causes an error on a TCP socket Normally the socket recovers from the error avoiding notice in the application layer for example Modbus or I O scanner However an er
220. by both stations reduces the chances of another collision A signal indicating that other stations are contending with the local station s transmission The signal is sent by the physical layer to the data link layer on an Ethernet IEEE 802 3 node With Ethernet each device can detect collisions and try to send the signal again CSMA CD is based on this principle A dedicated standalone system that manages communications activities for other computers A device that serves as a wiring hub in star topology network Schneider family of Ethernet devices and solutions cyclical redundancy check A way of checking for errors in a message by doing mathematical calculations on the number of bits in the message the results of which are sent along with the data to the recipient The recipient repeats the calculation on the received data If there are any discrepancies in the two calculations the recipient requests a retransmission from the originator 520 31006929 8 2007 Glossary crosstalk CSMA CD CSU DSU cut through Noise passed between communications cables or device elements Near end crosstalk is measured close to where the noise is introduced Far end crosstalk is introduced at one end and measured at the other carrier sense multiple access with collision detection An Ethernet and IEEE 802 3 media access method All network devices contend equally for access to transmit If a device detects another device s signal
221. by watchdogs is a more reliable way to determine the health of communications to a remote device 31006929 8 2007 299 Services Overview Device Monitoring via Watchdogs Standby Unit Monitoring To completely monitor the operation of a remote device and the connection to it a watchdog should be implemented To implement a watchdog from a SCADA system to a PLC send a single write register from the SCADA system to a register in the PLC The PLC increments this register the SCADA reads the new value back increments the value again and writes the value The cycle runs constantly The watchdog monitors the operations of the full network link between the two devices and the operations of the PLC and the SCADA systems It informs both devices of a device or network failure A simpler watchdog can be implemented by having the PLC read a value from a remote device or by reading a value that changes in a known way such as a counter from the remote device These two methods check the network link but do not enable the remote device to know the PLC status Note When implementing watchdogs via a register that is incremented be sure to account for the situation when the register rolls over e g from 32767 to 0 When implementing a hot standby system where communication links are monitored and where a failed link may trigger a changeover you need to know the status of the standby link All nonoperational links
222. c protocols such as IP traffic Make sure that all the protocols you require are in the list of allowed protocols firewalls Some RAS servers can incorporate or add a firewall A firewall can provide a very secure environment for the PLC and prevent almost all unauthorized attempts to access the PLC or network 31006929 8 2007 145 Planning and Layout Virtual Private A VPN creates private networks using a transport mechanism such as the Internet Network or public telephone network It routes IP through a secure tunnel created between two networks The idea is to create what appears to be a dedicated private link ona shared network using encryption and tunneling techniques VPN technology is a cost effective way to provide secure connectivity to remote locations over the public Internet Site to site VPNs can be used to provide connections to remote office locations This can save on expenses associated with costly leased lines VPNs also provide a secure means of connecting to a private network from any Internet connection Common VPN e remote access VPN The most common and familiar situation for remote access Environments may be that of an individual user connecting from a remote location such as a residence or travel destination to a private network at the user s place of employment The most common way to accomplish this today is using a VPN which is not only faster but more cost effective flexible and convenient th
223. cal Input to Remote Output Measurement The curves below illustrate the Quantum PLC response times for a when a signal is Setup sent from the local PLC to a remote output module Response Time The signal is triggered by a local Quantum input module scanned into the Quantum PLC at a repetition rate of 0 ms see p 174 copied to another internal variable within the PLC written to a remote Momentum output module with a response time of 2 ms Results are plotted for 1 8 16 and 32 devices 396 31006929 8 2007 I O Scanner Performance 140CPU65150 with Embedded Ethernet Port The 140CPU65150 used for the following measurements is at version 2 0 with its embedded Ethernet port at version 3 1 200 4 _ 150 4 8 v amp 100 4 50 4 0 T 100 150 200 PLC Scan Time ms The bottom curve shows that the response times for 1 to 8 devices are almost the same differing by only 2 ms at a 200 ms scan time The response times for 16 devices are 1 ms longer initially as scan time increases the difference in response times increases to 10 to 12 ms at a 200 ms scan rate The response times for 32 devices are 7 to 8 ms longer initially as scan time increases the difference in response times becomes larger e g 14 to 16 ms more at a 200 ms scan The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from Scanned D
224. cation error because the service is able to pass the data sent before the application error If the network cannot recover before the retry time out times the service registers an error to the application You need to decide if the application can tolerate service time outs and errors or if the network should recover before a service time out or error occurs Be aware of the service time outs and retry times before selecting a network redundancy strategy A faster network recovery time is generally more expensive and it may not be needed in your application Multiple Ethernet interfaces in a device are resilient when one of the Ethernet interfaces fails or when the attached network fails However they also require the communications to and from the device to be managed so all other devices can communicate to the active interface If two Ethernet interfaces are installed ina device there are two methods for handling communications two linked interfaces or two independent interfaces 288 31006929 8 2007 Services Overview Linked Interfaces Independent Interfaces Two linked interfaces share the same IP address and they appear to be a single Ethernet interface to the rest of the devices on the network The two interfaces automatically monitor their ability to communicate with the rest of the system and decide which one is available to the device and the outside network Enabling this solution requires no extra work Linke
225. ch other The response times for 16 devices increase by 3 to 4 ms For 32 devices response times are approximately 10 to 16 ms longer The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Scanned Device Output ms TSXP57304M v2 0 ETY 10 ms 20 ms 50 ms 100 ms 200 ms 5103 v3 1 Scan Scan Scan Scan Scan 1 device 25 44 105 206 406 8 devices 27 47 107 208 408 16 devices 31 52 112 213 413 32 devices 41 601 118 219 419 378 31006929 8 2007 I O Scanner Performance Premium I O Scanner Response Times Remote Input to a Local Output Measurement The set of curves below illustrates Quantum PLC response times when a signal is Setup sent from a remote input module to a Premium output module in the PLC Response Time The signal is e triggered by a Momentum input module with a response time of 2 ms e scanned into the Premium PLC at a repetition rate of O ms see p 174 e copied to another internal variable within the PLC e written to a local Premium output module Results are plotted for 1 8 16 and 32 devices 31006929 8 2007 379 I O Scanner Performance TSXP575634M CPU with Embedded Ethernet Port The TSXP575634M CPU used for the following measurements is at version 2 0 with its embedded Ethernet port at version 2 0 450 400 4 350 300 4
226. chitecture Schneider Electric recommendations for network layout are also discussed A bus topology has a similar layout to a more traditional automation network such as the Modbus Plus A single backbone cable connects all the devices on the network Terminators are placed at each end of the backbone to allow signals to be sent and cleared over the network Devices usually connected using T connectors can be installed anywhere along the bus o o UT D j Gy 1 terminator 2 backbone 3 T connector A section of backbone cable is known as a segment Several segments can be connected using bridges or repeaters as shown in the illustration below 1 Segment 1 2 Repeater 3 Segment 2 31006929 8 2007 43 Planning and Layout Only one device at a time can send or transmit a packet of information The packet travels the entire bus backbone cable For this reason a bus topology is considered a shared medium Terminators are very important because a cable break can result in all devices losing their ability to communicate Advantages Disadvantages Low cost Scalability is a problem it is difficult to change the network as your needs change As traffic and the number of devices increase the performance of the network decreases Easy installation all network devices are connected to a cable segment and you need only enough cable to connect the equipment that you have Th
227. chronized with the time server time allowing all alarms and file and program change time stamps across the plant to be recorded using the same time source Time synchronization allows you to track the order of changes in the plant without the need to manually set the time in each device Sequence of events recording allows the order of events across a plant or across multiple plants to be reconstructed or examined very accurately This application is based on the accurate time stamping of events at their source Action synchronization allows multiple devices across a plant to execute an operation at the same time It can be useful for starting drives along a conveyor or transferring products from one part of the plant to another 210 31006929 8 2007 Services Overview Time Synchronization Service Operation Detailed Service Operation The time synchronization service uses SNTP to distribute the time from the central server to all clients who request it at configured intervals By time stamping the requests and responses at each point in the exchange the clients can account for delays caused by the network Network loads and delays generally do not affect the time signal accuracy However the delay is assumed to be uniform so a delay that occurs on the request packet but not on the received packet may cause the client time to be inaccurate by a small amount After the client receives the time its internal clock kee
228. comes smaller The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Local Output ms TSXP575634M v2 0 10 ms 20 ms 50 ms 100 ms 200 ms ETY5103 v3 1 Scan Scan Scan Scan Scan 1 device 21 41 101 200 400 8 devices 22 42 102 201 401 16 devices 24 43 103 202 402 32 devices 30 49 107 207 406 31006929 8 2007 381 I O Scanner Performance TSXP57304M The TSXP57304M CPU used for the following measurements is at version 2 0 and CPU with a the TSXETY5103 Ethernet communications module is at version 3 1 TSXETY5103 Module 450 400 350 4 300 4 g 250 4 2004 E z 150 4 A 100 4 50 4 a 1 16 devices 0 i l 0 50 100 150 200 PLC Scan Time ms The bottom curve shows that the response times for 1 to 16 devices are identical or within 1 ms of each other The response times for 32 devices are 6 ms longer initially as scan time increases the difference in response times decreases slowly The table below shows the data used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Local Output ms TSXP57304M v2 0 10 ms 20 ms 50 ms 100 ms 200 ms ETY5103 v3 1 Scan Scan Scan Scan Scan 1 device 24 43 103 204 404 8 devices 24 43 103 204 404 16 devices 24 43 103 204 404 32 device
229. communication between PLCs to synchronize applications e field level communication see p 157 between PLCs PCs and field devices e transparent remote communication remote communication via the Internet telephone or radio link 31006929 8 2007 155 Services Overview Company Level Communication MSE ERP Systems and PLCs Supervision Systems and PLCs HMI Applications and PLCs Field Devices SNMP Company level communications use standard infrastructures and protocols to exchange high volumes of data with project management systems In some cases the PLC must adapt to a protocol specific to the connected system Response times are not critical The Transparent Ready services used are HTTP communication to display data and send commands via Web pages data exchange using the OPC standard via an OFS data server see p 256 Modbus TCP IP messaging see p 179 TCP open email transmission see p 277 direct publication in relational databases via the FactoryCast HMI active Web server see p 236 Company level communications may transfer high volumes of data from a corporate system to a group of PLCs Response times generally need to be in the 0 5 to 2 s range The Transparent Ready services used are data exchanges using the OPC standard via an OFS data server see p 256 Modbus TCP IP messaging see p 179 TCP open HTTP communication integrated in the supervision system to display Web pages fr
230. compacting and concatenating for optimization The located and unlocated variables in the Modbus read request generator provide a mixing technique read block offset length The read request generator can mix any variable type in the same request one variable equals one 6 byte identifier The NOE module can send only 1 request per CPU scan for unlocated variables and 4 requests per CPU scan for registers For example sending 1 Boolean 2 floating point integers and a structure with 5 integers would equal or exceed 1 request 31006929 8 2007 265 Services Overview Dynamic Performance Multichannel Feature MW2 MW3 MW4O0 mX5 MX8 gt 1 request with 3 elements MW2 3 MW40 MWXS5 8 The dynamic performance of OFS can be measured against several characteristics configuration response time read write response time volume of data exchanged e sensitivity to errors It can also be measured along 2 lines e OFS communication with devices e OFS communication with OPC clients In certain cases you must configure different OFS parameters to obtain better performance for example if devices are accessed via different types of networks and a lower performance network is used somewhere on the network path One of the server adjustment parameters that influences performance for OFS communication with devices is the multichannel feature Refer to the OPC Factory Server manual for more information about the d
231. ct is a product with a configurable Web server and advanced Ethernet communication services The services provided by a higher class include all the services supported by a lower class Transparent Ready products are chosen from 4 main families sensor and preactuator type field products simple or intelligent controllers and PLCs human machine interface HMI applications dedicated gateways and servers The following selection chart can be used for choosing Transparent Ready products according to the required service classes Web services Ethernet communication services Controllers and PLCs B20 C20 Simple and intel lig ent products ATO B10 Di 22 31006929 8 2007 Transparent Ready Users of this Guide Summary To successfully design and troubleshoot an industrial Ethernet system you need a mix of Ethernet IT and traditional automation knowledge A collaborative relationship between the industrial control engineer and the plant IT professional is key to the success of a Transparent Ready system Audiences Analysis for this Guide This table describes the two audience groups for whom this guide is written their areas of expertise and their information needs It also gives references to the sections of this guide where the needed information can be found Audience Expertise Knowledge Needs IT Professionals TCP IP protocol Architectural alternatives such as Ethern
232. cted is important in allowing network managers to control the way hosts end devices join groups and how routers exchange multicast information In IP multicasting each group has a multicast group ID a set of Class D IP addresses used to specify the destination of a message The addresses range from 224 0 0 0 to 239 255 255 255 Each multicast IP address can have a number of hosts listening to it Hosts can belong to a multicast group and the IP addresses are associated with that group Each configured device has a multicast IP address that is in addition to its own IP address Class D addresses can be classified as follows e permanently assigned addresses in the range 224 0 0 0 to 224 0 0 225 permanently assigned by IANA for certain applications such as routing protocols for example e 224 0 0 0 for the base address e 224 0 0 1 for all systems on this subnet e 224 0 0 2 for all routers on this subnet e 224 0 0 4 for DVMRP routers e nonpermanent addresses in the range 224 0 1 0 to 238 255 255 255 used for assignment as needed on the Internet e administered nonpermanent addresses in the range 239 0 0 0 to 239 255 255 255 reserved for use in private Intranets 31006929 8 2007 135 Planning and Layout Multicast Filtering Summary IGMP IGMP Snooping GMRP MAC Address Mapping with Class D Addresses Obtaining Group Membership Two services and one variation can be used for multicast filtering
233. ctromagnetic emission standards 76 electronic mail notification 218 device support 222 operation 220 optional password protection 221 service selection 159 elements of a Transparent Ready system 24 ELFEXT equal level far end crosstalk 514 embedded diagnostics service selection 160 EMC sensitivity signal classification 99 EMI prevention earthing methods 94 equipotential bonding 94 installation measures 94 methods 94 enable I O scanning 172 equal level far end crosstalk ISO IEC 11801 performance parameter 514 equipotential bonding creating an earthing system for a building 97 defined 95 local equipment 98 standard 96 to combat EMI in Ethernet networks 94 error handling for I O scanning 172 in a global data operation 199 Ethernet architectural considerations 320 in industrial applications 17 industrial 16 packet capture tool 368 Ethernet bus topology 49 Ethernet cable construction 110 Ethernet daisy chain topology 50 Ethernet frames 55 Ethernet II in the Transparent Ready model 127 Ethernet ring topology 51 Ethernet standards IEEE 802 3 32 ISO IEC 8802 3 32 Ethernet star topology 50 Ethernet systems broadcast domains 57 collision domains 56 LAN technologies 55 VLANs 57 wireless IP 58 evaluating a system 165 exception reporting in SCADA communication 277 F FactoryCast service selection 160 546 31006929 8 2007 Index FactoryCast HMI Web server service arch
234. d 32 devices The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Local Output ms 140CPU65150 v2 0 NOE771x1 10 ms 20 ms 50 ms 100 ms 200 ms v3 5 Scan Scan Scan Scan Scan 1 device 31 56 145 292 590 8 devices 31 56 145 292 590 16 devices 31 56 145 292 590 32 devices 31 56 145 292 590 394 31006929 8 2007 I O Scanner Performance 140CPU43412A with 140NOE771x1 Module The 140CPU43412A used for the following measurements is at version 2 0 with a 140NOE771x1 Ethernet communications module at version 3 5 700 600 a 500 4 m 400 4 Time ms 300 4 200 4 m 100 a 0 i T T T 1 0 50 100 150 200 250 PLC Scan Time ms The curves above show that the response times for all devices remain are the same for 1 8 16 and 32 devices The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Local Output ms 140CPU43412A v2 0 10 ms 20 ms 50 ms 100ms_ 200 ms NOE771x1 v3 5 Scan Scan Scan Scan Scan 1 device 35 64 168 334 634 8 devices 35 64 168 334 634 16 devices 35 64 168 334 634 32 devices 35 64 168 334 634 31006929 8 2007 395 I O Scanner Performance Quantum I O Scanner Response Times Lo
235. d flicker in 1994 EN 61000 low voltage systems for equipment having a 3 3 1995 rated current equal to or less than 16 A IEC 1000 3 5 Limitation of voltage fluctuations and flicker in 1994 low voltage systems for equipment having a rated current greater than 16 A Installation Requirements IEC 1000 5 1 General considerations IEC 1000 5 2 Earthing and Wiring IEC 1000 5 3 External Influences The IEC 1000 4 previously known as IEC 801 standard establishes a common reference for evaluating the performance of industrial process measurement and control instrumentation when exposed to electric or electromagnetic interference The standard considers only those types of interference caused by sources external to the equipment The standard describes interference susceptibility tests that demonstrate the capability of equipment to function correctly in its working environment You determine the type of tests to run based on the types of interference to which your equipment is exposed when installed taking into consideration the electrical circuit that is the way the circuit and shields are tied to earth ground the quality of the shielding and the environment The IEC 1000 4 standard is divided into six sections Test and Measurement Techniques 801 1 IEC 1000 4 1 1992 12 Overview of immunity tests EN 61000 4 1994 08 801 2 IEC 1000 4 2 1995 01 Testing of immunity to electrosta
236. d interfaces are commonly found in PC systems They are similar to Modbus Plus redundant ports in that you do not need to act to benefit from the two interfaces The interfaces monitor themselves and decide which interface to present to the outside network and to the device so they see only one interface Several Ethernet cards for PCs provide this functionality and their use is recommended ic em panj e am 1 Interface 1 provides a single presentation to the SCADA and the PLC it monitors the health of interface 2 to be sure that interface 2 can take over if it should fail 2 Device 2 monitors the status of interface 1 and shares the same IP address as interface 1 It does not present information to the SCADA and PLC unless interface 1 fails Each interface has a different IP address only one interface is active at a time This method of implementing multiple interfaces normally requires that you monitor the health of the interfaces within their application and decide which interface should be active For example with a SCADA package that has two unlinked Ethernet cards installed in a PC the system monitors both interfaces and chooses one Another example is that of two ETY modules in a Premium PLC All Schneider Automation devices use this method 31006929 8 2007 289 Services Overview You need to monitor the health of each interface and decide how to handle communications so that exchanges are not duplicated
237. d rates of both 9600 and 19 200 and on the amount of data i e the number of registers requested The following legend describes the baud rate and number of requests sent as tracked in all four of the charts that follow Curve Number of Requests Baud Rate 1 16 9600 19 200 9600 19 200 O o AJOJN 9600 19 200 31006929 8 2007 463 Gateway Performance Serial Devices with 50 ms Response Time 9000 8000 4 7000 4 a 6000 4 oe Time ms 0 20 40 60 80 100 12 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 50 Timeout EGX400 Time to Complete All Requests 1000 ms 1 Retry Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 2185 33 2628 663333 3135 33 2178 67 2575 336667 3028 167 172 16 2185 33 2978 663333 3885 33 2178 67 2750 336667 3403 167 172 32 2185 33 3351 996667 4685 33 2178 67 2937 003333 3803 67 172 64 2185 33 4098 663333 6285 33 2178 67 3310 336667 4603 67 172 100 2185 33 4938 663333 8085 33 2178 67 3730 336667 5503 67 172 464 31006929 8 2007 Gateway Performance Serial Devices with 100 ms Response Time Time ms 40 60 Nu
238. dard in digital transmission With respect to Ethernet an electrically continuous piece of the bus Segments can be joined together using repeaters or bridges The amount of time it takes a signal to propagate from one end of the segment to the distant end With respect to Ethernet splitting an overloaded ring into two or more separate rings linked by a bridge router or multipurpose hub A computer that provides resources to be shared on the network such as files file server or terminals terminal server A connection to a network service Ethernet configuration in which a number of segments are bound together in a single collision domain Hubs produce this type of configuration where only one node can transmit at a time See loss serial line Internet protocol A protocol for running TCP IP over serial lines A network concentrator that allows multiple media to be supported and managed from a central location When supporting structured wiring systems smart hubs provide port management single mode fiber A fiber with a small core diameter approximately 3 um and a cladding with a refractive index very close to that of the core It transmits light rays that enter at a narrow angle over very wide bandwidth SMF has a relatively narrow diameter through which only one mode propagates It carries higher bandwidth than MMF but requires a light source with a narrow spectral width short message service Text messages of up to
239. dbus function code 3 command The minimum time to respond to a single Modbus request is one PLC scan cycle The throughput capacity of five systems is measured a 140CPU65150 with a 140NOE77101 Ethernet communications module a 140CPU65150 with a 140NOE77111 Ethernet communications module a 140CPU43412A with a 140NOE77101 Ethernet communications module a 140CPU43412A with a 140NOE77111Ethernet communications module a 140CPU65150 with an embedded Ethernet port 450 400 4 350 Number of Modbus Transactions s or T T T T 50 100 150 200 250 Scan Time ms The four bottom curves all with equal values and hence appearing as one line show throughput for the four CPUs that use NOE modules The upper curve shows throughput for the CPU with an embedded Ethernet port As scan times increase the difference in throughput capacity the number of Modbus transactions messages between the CPUs with NOE modules and the CPU with the Embedded Ethernet port decreases 402 31006929 8 2007 Modbus Server Performance The table below shows the data points used to generate the graph represented above Scan Time 65150 65150 65150 43412A 43412A ms Embedded Port NOE77101 NOE77111 NOE77101 NOE77111 Scan Time Number of Modbus Transactions Second 10 400 100 100 100 100 20 400 100 100 100 100 50 320 120 120 120 120 100 160 80 80 80 80 200 80 40 40 40 40
240. ddresses 255 248 0 0 524 288 255 252 0 0 262 144 255 254 0 0 131 072 255 255 0 0 65 536 255 255 128 0 32 768 255 255 192 0 16 384 255 255 224 0 8 192 255 255 240 0 4 096 255 255 248 0 2 048 255 255 252 0 2048 255 255 254 0 1024 255 255 255 0 512 255 255 255 128 128 255 255 255 192 64 255 255 255 224 32 255 255 255 240 16 255 255 255 248 8 255 255 255 252 4 255 255 255 254 2 255 255 255 255 1 For a subnet with 64 addresses the subnet mask is 255 255 255 192 The IP address would therefore be 192 168 1 1 the network address would be 192 168 0 and the host range would be from 0 1 to 63 Using Subnetsin By using subnets in your plant you can divide the plant into sections to avoid traffic a Plant overload Use a router to pass traffic between subnets There should be no more than 200 to 300 devices per network However it is preferable to have a smaller network with 50 to 100 devices Add networks if you must accommodate more devices than the preferred number 31006929 8 2007 133 Planning and Layout Assigning You may obtain addresses from the governing organization or use a group of those Addresses already assigned to your company The next step is to assign a unique address to each end device by one of several methods In static addressing each user is assigned one fixed IP address to be used every time the user connects to the Internet Dynamic addressing assigns the IP automatically as needed BootP
241. dual publisher is longer than the configured health time out the service informs the user application on the subscriber device of an error The subscriber must perform error monitoring and take action if the data is not received This is different from Modbus communications where a command is sent to another device to perform an action In the case of Modbus the device sending the command must know if it is successful With global data the publisher just makes the information available and leaves it to the subscriber to receive and act on the information If for any reason a subscribing device does not receive a particular copy of newly published data to which it subscribes the device receives an update of that data in the next publication cycle The global data service publishes status information at a fast regular rate and the next subsequent publication provides the current status of the subscription data rather than a retry of the previous data 31006929 8 2007 199 Services Overview Limits The following figure shows a distribution group comprising four devices D1 through D4 Two of these devices are publishers D1 and D2 and three are subscribers D2 D3 and D4 Device 2 is both a publisher and a subscriber The data flow illustrates how devices 1 2 and 3 all subscribe to data published by device 1 and device 4 subscribes to data published by both devices 1 and 2 Publish
242. e Goss oe tte tel Man OAs RAS hee eee eS 59 Other LAN Considerations sasaaa aaeeea 61 WAN Technologies and Network Design 000 c eee eee eee 62 WAN Hardware sisii a fats a iene aed a a dati le ae ace ates wets Aus 65 Environmental Requirements 0 00 e eee eet ees 67 Environmental Standards Summary 00 0c cece eee eee ee 68 Mechanical Requirements 0 00 e cee ete tenes 69 Climate Protection Requirements 0000 c cece eee eee eee 71 Ingress Protection Requirement 0 20 2 c eee eee ee eee 73 Electromagnetic Emission and Immunity Requirements 76 Selection of Industrial Ethernet Components 000 0s eee eee 77 Ethernet Copper Cables 2 0 0 0 c cece cette 78 2 5 2 6 2 7 Chapter 3 3 1 Fiber O ptic CabliNga pase nra ea uiad E E e E ter E A ee E 82 10 100BaseF Physical Layer Specification 0000 cee eee 86 Ethernet Connectors for Copper Networks 000 cece eee eee 87 Fiber Optic Connectors 0 0 0 cette eee 90 Recommended Infrastructure Devices for Industrial Ethernet 92 Installations is iaa ues acd aoe a ate neds Gyan lad Goch E a E AR ewe Me aed 93 EMC Installation Rules for Ethernet Networks 00 0 cece ee eae 94 Equipotential Bonding 0 eect teens 95 Equipotentially Bonding Your Building 0 2 eee eee eee 96 Local Equipotential Bo
243. e an application on a Quantum system can initiate Modbus client communications using the following Modbus client blocks MSTR READ_REG WRITE_REG C_READ_REG C_WRITE_REG The Quantum PLC reads and writes to the 4x or MW data area only Up to 16 concurrent Modbus client blocks can be triggered by an NOE Ethernet communications module If additional blocks are triggered they are buffered until one or more active blocks complete their operations A Quantum Modbus client operates as follows Sequence Event 1 The application triggers the Modbus client block 2 The request is immediately sent to the NOE Ethernet communications module 3 The NOE module checks if a TCP socket is connected to the destination device 4 If a TCP socket is not connected the NOE initializes a TCP socket and connects it to the destination device The NOE module sends the Modbus request The message travels across the network and a network delay occurs The Modbus server receives the message The Modbus server responds to the request oOo NI oO The message travels across the network and a network delay occurs 10 The NOE receives the response 11 The next time the Modbus client block is reached in the code the response is gathered from the NOE module and any new data is made available to the user application 12 The NOE leaves the TCP socket open for future use Note The NOE module
244. e answers after 80 ms The response is read back into the PLC the next time the read function is called and this can take up to one CPU scan 70 ms The Premium triggers a write function during the same CPU scan and sends the response at the end of the scan 70 ms The field device receives the response and sets the output 30 ms The total time is 70 ms 80 ms 70 ms 70 ms 30 ms 320 ms Given A SCADA system is polling a Quantum PLC running Unity Pro software The Quantum CPU scan time is 140 ms The SCADA system is polling the following items every second 250 registers for trending 750 bits for alarms 30 registers for a current screen being displayed 20 bits for a current screen being displayed 1 bit write to start a motor in response to a user command on the current screen 332 31006929 8 2007 Services Overview In order to calculate the number of requests you can either look at the configuration and determine the number of requests being sent or you can estimate the number of requests In this case the number of requests has been provided for you Note that not all registers are in congestive order so the number of requests is more than the ideal amount 3 requests for trending every second 6 requests for alarms every second 8 requests for registers being displayed on the screen every second 4 requests for bits being displayed on the screen every second The variables are located according to the fo
245. e PLC devices such as Quantum and Premium e Modbus serial devices such as Lt6 motor relays that are accessed through a bridge e any third party device that is a Modbus TCP IP server The I O scanner reads and writes data repetitively in a user configurable period ranging from 20 ms to 5 s These read write exchanges generate a load on the network For this reason the I O scanner is best suited for critical periodic operations The I O scanner is configured with a list of devices data areas and the rate at which the register data exchange takes place The scanner establishes a connection to the remote device and exchanges data at the configured rate The I O scanner maintains the connection to the remote device while handling any errors that occur For each remote device a report is sent back to the application indicating whether the data is being transferred within the specified exchange rate I O scanner is an open system you are not bound to any particular platform or to the same brand name The I O scanner system consists of two parts the scanning device and the remote device s The scanning device has no control over the remote device For example if the device fails the I O scanning device cannot issue its fallback state The I O scanning device has the ability to issue what state its application value should have in the case of lost communication to the remote device There are no individual configurable parameter screens avail
246. e SCADA client server model 286 MSTR block to monitor Ethernet communications in a Quantum system 299 multicast technology for global data 202 N near end crosstalk loss ISO IEC 11801 performance parameter 513 network access from a remote station 142 network congestion in an Ethernet system 56 network design 165 network interface layer in the TCP IP model 126 network management for an Ethernet system 137 NIC operating system 349 noise immunity standards 76 nominal impedance ISO IEC 11801 performance parameter 512 notification service in an OPC factory server operation 262 NTP troubleshooting 362 O OMNIscanner 2 certification tool for copper cable installations and performance 120 OPC factory server asynchronous services 262 build time runtime option 268 compacting items of the same type 265 concatenating requests 265 notification service 262 optimizing requests 265 runtime architecture 267 services 258 size of requests 264 synchronous services 261 with multiple SCADA connections 272 open standards in Ethernet for automation 123 operating system logical check 349 NIC 349 operating temperature range requirements 71 OSI model 124 P packet capture tools 368 troubleshooting 369 packet switching in an Ethernet system 63 packets lost 367 troubleshooting 367 31006929 8 2007 551 Index pair to pair attenuation of crosstalk ratio ISO IEC 11801
247. e a remote device It is a text based user interface that is integrated with many devices today Telnet may be used to configure simple devices such as switches routers and serial to Ethernet bridges For details see p 247 31006929 8 2007 161 Services Overview Plant Data Transfer Services Service Level Response _ Data Exchange Examples Communications Common Time Transfer Confirmation Topology Use Frequency I O field device 10 ms 1ms 5s I O scanner controlling central scanner scanning and PLC to periodic health status for Advantys I O device PLC data transfer and plant status exchanging data levels 2 and 3 fallback values transfer between with one or more Acknowledgmen PLCs remote devices t of each data transfer with retry mechanism Modbus field devices 50 ms occasional or acknowledgment confirmation of Client device to messaging PLC to PLC nonperiodic of each data process server device and exception transfer with completion supervision reports retry mechanism SCADA HMI levels 1 2 communications and 3 Global data PLC to PLC 20 ms 10 ms 30s none device status many publishing level 2 periodic distribution to a devices to many group of devices subscribing devices TCP open field device 100 ms 100 ms or user programming a one client to one to PLC PLC exception configurable new server to PLC PLC based communications to su
248. e automation industry Because it is an open technology Ethernet offers a wide range of products and services from multiple vendors The advantages of an open approach are clear you are no longer subject to the communication constraints costs and development schedules of a proprietary vendor for your system needs However some Ethernet components may not interoperate optimally in an industrial environment and not all Ethernet devices support all the services you may want To successfully design and troubleshoot an industrial Ethernet system you need a mix of Ethernet IT and traditional automation knowledge This guide is designed to help bridge the gap between these two disciplines 31006929 8 2007 11 About the Book The guide should be used as a supplement to product specific Transparent Ready user manuals To learn more about commercially available Transparent Ready products refer to the latest Transparent Ready catalog or go to www telemecanique com Validity Note The data and illustrations found in this book are not binding We reserve the right to modify Schneider Automation s products in line with Schneider Automation s policy of continuous product development The information in this document is subject to change without notice and should not be construed as a commitment by Schneider Electric Related Doc ments Title of Documentation Reference Number
249. e can be located on the same PC where the OFS SCADA and Unity Pro XL system run e Unity Pro XL is needed for the OFS operating modes This is the only architecture that lets you run in server mode which is mandatory for the dynamic update of the symbols Unity Pro XL must be installed OFS launches Unity Pro XL and opens the application in background mode e The OFS Unity Pro XL system runs on one PC e The SCADA is executed on a dedicated PC and communicates with OFS DCOM for real time access to the PLC e Unity Pro runs on a separate PC for application modifications This PC does not need to be connected to the network permanently but only for on line modification e The PC server for the STU application files provides consistency so that all the OFS and Unity Pro stations use the same application data for the modifications and synchronization e OFS accesses the data from the PLC in real time It detects any discrepancies between the running application and the local symbol file on the PC signature checking In accordance with the OFS QoS the communication stops or switches to a bad quality service e OFS Unity Pro XL updates the symbols by accessing the STU file Depending on the OFS settings this update can be automatic or triggered by the SCADA application through a specific command mode in OFS The application does not stop Only the OFS communication is interrupted during the symbol file update e Any on l
250. e channel is specified at and between interfaces to the channel e The performance of a permanent link is specified at and between interfaces to the link The ISO IEC 11801 also states The link performance is met when components specified in clauses 8 and 9 of the ISO IEC 11801 are installed in a workmanlike manner and in accordance with supplier s and designer s instructions over distances not exceeding those specified in clause 6 of the ISO IEC 11801 31006929 8 2007 509 Earthing Grounding Procedures Performance Parameters Introduction Specification Parameters and Vendors of components and cables are required by the ISO IEC 11801 standard to publish performance parameters for their products The standard states that vendors of cables and components are required to present parameters for the different components of a permanent link or channel whose specifications are defined in chapters 8 and 9 of the ISO IEC 11801 The performance parameters specified by the ISO IEC 11801 apply to permanent links and channels with shielded or unshielded cable elements i e with or without an overall shield unless explicitly stated otherwise STP and UTP are also referred to as balanced cabling Performance parameters are defined for 5 application classes For example class D applications are related to class D permanent links and channels which are specified up to 100 MHz The following table lists all parameters pr
251. e devices are usually connected using taps into the trunk cable If a device or segment is lost all the devices further down the line could become unavailable The backbone follows the a path around the plant much like a proprietary automation network making the network design easy to understand for designers new to Ethernet in automation applications Because all the devices share the same backbone cable the throughput is limited only one device can communicate at any time The speed of all devices on a bus network must be the same Star Topology In a star topology all the devices are connected though a central device A star topology is a common network layout for office environments and also for newer automation environments star o o oo Q o o aut Hint 44 31006929 8 2007 Planning and Layout Daisy Chain Topology In a star topology devices can use dedicated sections of the network for various services Advantages Disadvantages Network throughput is much higher than on a shared media bus topology Network reconfiguration is much easier Centralizing network components makes administration easier centralized management and monitoring of network traffic enhances network performance Diagnostics are simple if a network segment fails it affects only the devices directly connected to that segment Infrastructure c
252. e materials prevent direct contact with other metal surfaces Between Two in an earthing system Metal Surfaces 31006929 8 2007 501 Earthing Grounding Procedures Follow these steps to make an EMC compliant connection between two metal surfaces Step Action Comments 1 Select appropriately conductive Here is a braided strap connection connection materials for optimum contact Use braided straps or bolts to connect metal surfaces A metal plate or bar is less preferable but may be used in the absence of a braided strap Do not use green yellow wire conductors 2 Prepare the surface for metal This includes the surfaces between any two continuous connections connections at all contact points that are placed in contact such as two flat metal sheets or bars Remove any paint or insulating coatings from the surface of metal contact points 3 Attach connection surfaces using Make sure the connection between contact surfaces is tight by using braided straps or nuts bolts and a nut and bolt system with a washer washers 502 31006929 8 2007 Earthing Grounding Procedures Step Action Comments 4 Make sure all metal components are interconnected and attached to an earthing system Recheck your connections to make sure they create a local earthing system that attaches to the earthing main conductor for your building see p 96 Long PE
253. e shielded connectors on cables devices and switches 2 Install an earth bus bar or plane Make sure there is no insulating covering or paint on the surface to connected to a chassis to which you which plan to attach the cable Do not use soldered cable lugs or will attach the cable shielding You tinned leading out wires to connect cable shielding If possible plan to can also attach cable shielding at connect the cable shield to an earth bus bar or at the point of entry to entry points to cabinets a cabinet In all cases make sure you have allowed for a strong metal to metal contact that surrounds the cable 360 degrees 3 Check the cable to make sure you If the cable is damaged or the cable shielding is cut replace the entire have an uninterrupted cable shield length of cable from end to end 504 31006929 8 2007 Earthing Grounding Procedures Step Action Comments 4 Remove the outer plastic jacket to expose the internal cable sheath An excellent metal to metal contact must exist between the mesh cable shielding and the metal bus bar or earth plane Expose the cable shield so that it has a 360 degree contact surface to make a good ground connection 5 Attach the cable shield If possible connect the cable shield to an earth bus bar or at the point of entry of a cabinet Wherever possible ground both ends of a cable by attaching them properly to an earth plane Make sure t
254. e smaller wires The only benefit of using stranded cable which is typically more expensive is its smaller bend radius you can squeeze it around tighter corners with lower loss In most other respects the performance of the two cable types is the same 31006929 8 2007 79 Planning and Layout Physical Layer Specification The following table provides a summary of some of the various physical layer specifications defined for Ethernet Standard Data Rate Connector Medium Maximum Cable Technology Segment Length Half Duplex Full Duplex 10Base T 10 Mb s 20 Mb s in RJ45 two pairs of 100 Q CAT 3 100m 100 m optional full duplex or better UTP cable 100Base TX 100 Mb s 200 Mb s in RJ45 two pairs of 100 Q CAT5 100 m 100 m optional full duplex mode UTP cable 1000Base T 1 Gb s RJ45 four pairs of 100 Q CAT 5 100m 100 m or better cable 100Base TX supports transmission over up to 100 m of 100 Q CAT 5 UTP cabling CAT 5 cabling used with 100Base T is a higher grade wiring than CAT 3 used with 10Base T It is rated for transmission at frequencies up to 100 MHz CAT 3 cabling supports transmission only up to 16 MHz The 100Base TX standard supports the option of using 150 Q STP cabling Cable Color The EIA TIA 568B standard defines the pinout for wires in RJ45 8 pin modular Specifications connectors plugs and jacks It also defines the color code for the 8 wires in the four pairs
255. e system needs the Unity Pro XVM symbols file to be compatible with OFS The symbols file is exported in Build mode by Unity Pro and must be copied on the PC that is used to run the system A symbols file is needed for each PLC application The SCADA OFS XVM files system runs on one PC Unity Pro runs on a separate PC for application modifications This PC is not necessarily connected to the network permanently it may be connected only for on line modification or XVM file copying to the OFS system OFS accesses the data in the PLC in real time Any discrepancies between the running application and the local symbols file on the PC initiates signature checking In accordance with QoS for OFS the communication stops or switches to a bad quality service You must manually update the PC with the correct symbols file in order to have consistency between the symbols file and the application running in the PLC The update can be triggered by the SCADA application through a specific command mode of OFS The application does not stop Only the OFS communication is interrupted during the symbols file update Product Version Comments Unity Pro M L XL v2 0 VijeoLook v2 6 includes the correct version of OFS MonitorPro v7 2 without access to the structured variables 31006929 8 2007 269 Services Overview Build time Runtime Architecture for Unity OFS SCADA Systems that Require Frequent Modification
256. e triggered by a Momentum input module with a response time of 2 ms e scanned into the Premium PLC at a repetition rate of O ms see p 174 e copied to another internal variable within the PLC e written to a Momentum output module with a response time of 2 ms Results are plotted for 1 8 16 and 32 devices 31006929 8 2007 375 I O Scanner Performance TSXP575634M The TSXP575634M CPU used for the following measurements is at version 2 0 with CPU with its embedded Ethernet port at version 2 0 Embedded Ethernet Port 450 4 350 Time ms 8 S 32 devices 50 4 1 16 devices 0 50 100 150 200 PLC Scan Time ms The bottom curve shows that the response times for 1 to 8 devices are within 1 ms of each other The response times for 16 devices increase by 2 to 3 ms For 32 devices response times are approximately 11 to 14 ms longer The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Scanned Device Output ms TSXP575634M v2 0 10 ms 20 ms 50 ms 100 ms 200 ms Embedded Ethernet Port v2 0 Scan Scan Scan Scan Scan 1 device 25 45 106 205 406 8 devices 26 46 107 206 407 16 devices 28 48 108 207 409 32 devices 39 61 120 224 421 376 31006929 8 2007 I O Scanner Performance TSXP575634M The TSXP575634M CPU used for the following meas
257. eaches its limit of TCP sockets At that point the ETY module closes any socket that has no outstanding requests on it The ETY module can send multiple requests down a single socket 31006929 8 2007 187 Services Overview Modbus Client Operations in Momentum Systems Limits Using Unity Pro Concept or Proworx programming software an application running on a Momentum system can initiate Modbus client communications using the following Modbus client blocks MSTR READ_REG WRITE_REG C_READ_REG C_WRITE_REG The Momentum PLC reads and writes to 4x or MW data register areas only Up to 16 concurrent Modbus client blocks can be triggered If an additional block is triggered it returns an error code to the application Momentum A Momentum Modbus client operates as follows Modbus Client gt Sequence Event Operations 1 The application triggers a Modbus client block 2 The processor holds the request until the end of the current CPU scan 3 At the end of the current CPU scan the Momentum PLC begins to open a socket to the destination device and a SYN message is sent The Modbus server responds with a SYN ACK 5 At the end of the next CPU scan the Momentum PLC receives the SYN ACK and opens the socket 6 As soon as the socket is open the Momentum sends the Modbus request 7 The message travels across the network and a network delay occurs 8 The Modbus server recei
258. eady in place checked to verify that it can transport the required services Items to be checked include networks subnets see p 132 and addressing see p 130 bandwidth routers see p 139 and firewalls see p 150 RAS see p 144 31006929 8 2007 165 Services Overview 3 2 I O Scanning Service At a Glance Overview This section describes the I O scanning service and how it is used to exchange data between a central device and many remote devices What s in this This section contains the following topics Section Topic Page I O Scanning Service Description 167 I O Scanner Operation 169 Repetition Rates 174 Some Common Fault Conditions 176 Response Times 177 166 31006929 8 2007 Services Overview I O Scanning Service Description The I O Scanning Service I O Scanner Characteristics The I O scanning service is a stand alone communications task that exchanges register data between one device running the service and many remote devices on the network using Modbus TCP The service requires only a simple configuration operation in the I O scanner device no special programming is required in either the I O scanner device or the remote devices The remote device must be a Modbus TCP IP server Examples of remote devices include e distributed I O such as Advantys STB and Momentum e intelligent devices such as Altivar drives and Sepam circuit monitors
259. eady services 156 compatibility of services 165 component testing cabling 112 configuration services 165 configuration software for a FactoryCast Web server 231 conformance recommendations for installing Ethernet copper cable 115 544 31006929 8 2007 Index connecting a PLC to the Internet 142 147 connectors fiber optic 90 fiber optic LC 90 fiber optic MT RJ 90 fiber optic SC 90 fiber optic ST 90 M12 89 M12 pinouts 89 RJ45 87 RJ45 pinouts 88 shielded RJ45 87 copper cable for Ethernet systems 78 copper cables tools for building 108 110 crimper for building Ethernet copper cables 108 110 crossover copper cable color code 106 pinout 106 crush requirements 70 CSU DSU hardware in an Ethernet WAN 66 cutter for building Ethernet copper cables 108 110 D daisy chain topology 45 data lost packets 366 packet capture 368 369 troubleshooting 366 data transfer communication Transparent Ready services 157 data transfers combining 165 DC loop resistance ISO IEC 11801 performance parameter 515 degree of protection ingress protection requirements 74 delay scew ISO IEC 11801 performance parameter 515 designing a network 165 device support for a FactoryCast HMI Web server 241 for a FactoryCast Web server 235 for a Web server 229 for electronic mail notification 222 for faulty device replacement 207 for global data 201 for Modbus messaging services
260. ed l This system avoids problems with devices that are unable to handle multiple requests on the same socket but the end device may still become overloaded due to the total number of requests The system response time is 150 ms 284 31006929 8 2007 Services Overview I O Server and Display Client Communications Client communications between an I O server and a display are commonly based on one or more of the following e proprietary systems and protocols e OPC client server communications e MS Windows communications Because most SCADA to SCADA communications rely on some form of MS Windows networking service Com DCom machine names etc this service must be installed on the network However by installing this type of service the network becomes loaded down with additional MS Windows traffic and is susceptible to overloads by MS Windows and other traffic SCADA to SCADA communications should be separated from the normal device communications network whenever possible You can do this by installing separate Ethernet cards into the SCADA PCs and running a separate Ethernet network for SCADA to SCADA communications 31006929 8 2007 285 Services Overview Schneider Product Implementation Details VijeoLook Implementation Monitor Pro Implementation VijeoLook uses the Schneider OPC server for communications see p 257 Monitor Pro supports the I O server multiple clients model When
261. ed by Schneider Electric for any consequences arising out of the use of this material 2007 Schneider Electric All Rights Reserved 31006929 8 2007 Safety Information 10 31006929 8 2007 About the Book At a Glance Document Scope This user guide deals with the broad topic of industrial Ethernet a key element of Schneider Electric s Transparent Ready strategy The purposes of the guide are twofold e to describe the impact of industrial Ethernet on new control system designs e to give you the information you need to implement and support a Transparent Ready solution that best meets your application requirements The guide describes four key parts of a successful system implementation e planning a system for optimal performance e selecting the right Ethernet services and devices for your application e making the right choices as you design and install the system e troubleshooting system problems effectively The guide is written for e design engineers system integrators and maintenance engineers who understand industrial control systems and requirements but may not be familiar with Ethernet products and services e plant IT staff who understand the principles of Ethernet system design and installation but may not be familiar with industrial control requirements and environments Ethernet technology is well established in the business and commercial worlds but it is relatively new to th
262. elated to cables Did you implement the correct cable type and quality Did you account for cable interference issues noise and ground Is the implementation of straight and crossover cables appropriate Are the settings and configurations appropriate for duplex transmission speed communications interference wireless connections common interference 346 31006929 8 2007 Troubleshooting Logical To troubleshoot more complex logical connections one must first have an Connections understanding of physical connections and network components Generally logical connection troubleshooting requires some expertise with specific software utilities and applications although you can fix some problems with standard DOS commands that work with most off the shelf operating systems Poor network administration is often the cause of logical connection problems If you don t restart the system before you fully test recent administration changes end users can have problems much later especially when they try to connect specific applications or programs after a system restart Administration changes that are likely to cause logical connection issues include e critical application changes or server operating system changes DHCP servers DNS servers mail servers etc e changes to logins policies scripting and authentication e security changes firewall rules port services and encryption setti
263. elongs exclusively to a distribution group The publication of data is synchronized at the start of the CPU cycle after the configured publication rate has been reached Subscribed data is recopied in the application memory of the subscribing device at the end of the CPU cycle after the data is received 202 31006929 8 2007 Services Overview Response Time Global data response time is measured from a status change in the publisher to the time when the change is known in the subscriber publication time 1 CPU scan on the publisher publication time of the service network time subscription time of the subscriber 1 CPU scan on the subscriber where publication time of the service and subscription time of the subscriber are generally 1 to 2 ms each Note ETY systems need to include one additional CPU scan on the subscriber The following diagram shows system start up times for a Premium ETY Ethernet communications module and a Unity Copro module The response times for both devices are measured with each device used as a subscriber and as a publisher 3 50 3 00 2 50 2 00 1 50 Time in ms 1 00 0 50 9 09 16 32 64 128 256 512 1024 Length ETY subscriber ETY publisher Copro subscriber a Copro publisher The following diagram shows the maximum time required to reach a steady state measured in seconds 70 60 50 40 Time
264. em Pipeline Servers should support pipeline requests but you should not necessarily implement requests pipeline requests at every opportunity For more information see gateway see p 304 and Modbus messaging see p 179 Pipeline requests occur when a new request is sent over a single socket before the previous request has been answered If the server cannot process a pipeline request it will respond with an error code the error code is likely to be request not supported or server busy especially if the server is a serial to Ethernet bridge e discard the request without a response crash You can only identify this problem through e knowledge of the device operation packet inspection with an Ethernet packet capture tool A subsequent problem arises when a device sends multiple Modbus requests in a single Ethernet packet which the Modbus specification does not permit This can cause the same problems as above but more likely scenarios include a request discard or a device crash Incorrect If a Modbus request returns an incorrect response either incorrect data or data of the response wrong type or size the client server may be incorrectly using the Modbus transaction IDs Transaction IDs in the Modbus TCP not serial specification support pipeline requests although all devices do not implement them This returns incorrect data making the device non compliant with the Modbus TCP IP specification Inspect the request and response with
265. ent device with a new MAC address without updating the server table e A firewall or router prevents the client from reaching the server Set up the server as a DHCP relay agent to correct the problem When the client does not obtain an IP address it either reports an error code or goes to the default IP address or both If you are not familiar with the network use an Ethernet packet capture tool to detect the problem Slow response from the server causing a timeout on the client A server can respond slowly when e overloaded for example many devices powered up at the same time e client and server are powered on at the same time generally client devices boot up faster and can send a request to the server before the server is operational When there is a slow server response the client does not get an IP address It either reports an error code or goes to the default IP address or both You can distinguish slow server responses from the errors above only with a packet capture tool Use an Ethernet packet capture tool to detect the problem Server sends negative response preventing the device from obtaining an IP address Multiple DHCP BootP servers connected to the same network can create multiple responses to the same request One server response can offer the correct address while another server response reports that no address is available The negative response can cause the client to go to an
266. ents Heavily polluted environments require more insulation Another option is to create clean micro environments for circuits and sensitive equipment using enclosures encapsulating methods and hermetic sealing Four levels of pollution are defined by standard IEC 60664 1 nsulation coordination for equipment within low voltage systems Part 1 Principles requirements and tests Pollution Level Description Grade 1 Nonpollution or only dry nonconductive pollution This type of pollution has no electromagnetic or other influence Grade 2 Normally only nonconductive pollution Temporary conductivity caused by condensation may also occur Grade 3 Conductive pollution or dry nonconductive pollution that becomes conductive due to condensation Grade 3 pollution occurs in industrial environments and construction environments that are considered harsh Grade 4 Pollution that generates persistent conductivity caused by conductive dust rain or Snow Pollution Table The following table shows the recommended levels of pollution allowed for industrial for Industrial automation devices and Ethernet infrastructure components Ethernet Environment Pollution Level Allowed Reference Light Industrial Light Duty Grade 2 IEC 1010 IEC 60664 1 Heavy Industrial Heavy Duty Grade 3 IEC 1010 IEC 60664 1 31006929 8 2007 73 Planning and Layout Degree of Protection IP Ratin
267. er FactoryCast people single or multiple plant information displaying plant several Web operation status with browser clients simple customized Web pages FactoryCast people single or multiple plant information remotely viewing plant many Web HMI machines status efficiently with browser clients advanced customized Web pages and applications SNMP machines single or multiple device network monitoring plant network information network status by management network management system to many HP Open view SNMP devices Telnet people single device monitoring internal one Telnet client device status to Telnet server in a device 164 31006929 8 2007 Services Overview Configuration Services Checking Service Compatibility Combining Data Transfers System Evaluation Network Design Service Configuration of Configured by Example FDR devices on the an FDR server automatically configuring an network by an FDR providing automatic Ethernet distributed I O device s server configuration of client operating parameters after the devices device is connected to the network Embedded a device connected to a person configuring a variable speed diagnostics by a user drive s operating parameters with a Web browser SNMP a device connected to a person or a network configuring network by a user or a network management system infrastructure component mana
268. er Sum NEXT is the sum of all pair combinations for crosstalk measured at the Near End to the transmitter and simulates all four pairs being operated simultaneously It is the addition of the NEXT effects of three disturbing pairs in the fourth pair considered in the Near End This parameter is intended for systems in which more than two pairs are used PSNEXT varies with the frequency and therefore you need to measure it within a range of frequencies The attenuation of crosstalk ratio ACR is the difference between the NEXT and the attenuation in the pair under test The formula is ACR NEXT Attenuation At the near end the NEXT is the strongest smallest NEXT value and the attenuation is the strongest which means the largest attenuation and the lowest signal level ACR is nearly analogous to the definition of signal to noise ratio ACR excludes the effect of external noise that may impact the signal transmission Power sum ACR PSAR is a mathematical calculation that simulates all four pairs being operated simultaneously The formula is PSACR PSNEXT Attenuation Because PSACR is a measured signal to noise ratio a larger number more signal and less noise is more desirable than a smaller number more noise and less signal Far end crosstalk FEXT is similar to the NEXT Even though the disturbing pair sends the signal from the local end it is measured in the disturbed pair at the far end The signal in the di
269. eration access to the CPU memory The NOE module uses these paths to read write 4x registers directly on the CPU memory for Modbus FC3 FC16 and FC23 The type 2 backplane path allows the Modbus message to be passed to the CPU The NOE uses this path to pass all other function code requests to the CPU the CPU handles the Modbus message Function code examples include unlocated variables FC42 PLC programming software FC125 FC43 and read write Ox 1x 3x requests The type 2 path is not used to answer requests for 4x registers FC3 FC16 and FC23 The number of backplane paths limits the Modbus server performance For example if 10 FC3 and 5 FC42 Modbus requests are queued inside the NOE module a total of 5 CPU scans is needed to compete the transfer During the first 3 CPU scans 10 FC3 4 per CPU scan and 3 FC42 1 per CPU scan requests are transferred but an additional 2 CPU scans are needed to transfer the remaining 2 FC42 requests 190 31006929 8 2007 Services Overview Unity Modbus In a Unity Modbus server system path types and uses remain the same but Server performance is improved 2 to 4 times over the Concept system Performance 8 Backplane Type 1 Paths FC3 FC16 and FC23 a am et agi a p e p a al a agi CPU p gt NOE e p gt Module 4 Backplane Type 2 Path All other FCs a al lt a ai ra ai a ai The Unity 2 0 NOE backp
270. erference is encountered chiefly in radiated form such as electrostatic discharges in the air The radiated energy is generally low and results in the malfunction of nearby equipment and devices HF interference pulses with a pulse rise time of less than 10 ns It can occur continuously for example in rectifiers and clocks The frequency range is gt 30 MHz HF type interference may also encountered in conducted form as transient current or voltage A transient is a temporary oscillation in a circuit that occurs as the result of asudden change of voltage or load For example it could be caused by a lightning strike or an electrical fault Electrostatic discharges disturbances can also be conducted along conductors and easily injected into other conductors by radiation LF and HF The following table provides an overview of the sources of LF interference Interference Type Possible Sources Effects of EMI Harmonic inverters choppers malfunction of connected Interference bridge rectifiers electrolysis welding machines devices etc potential destruction of arc furnaces connected devices induction ovens electronic starters electronic speed controllers for DC motors frequency converters for induction and synchronous motors domestic appliances such as televisions gas discharge lamps and fluorescent tubes 31006929 8 2007 491 Standards and Considerations Type Possible Sources Effects of EMI
271. ering Task www ietf org IETF is a large open international community of Worldwide Force IETF network designers operators vendors and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet It is the organization taking care of the Internet suite of protocols TCP IP Dedicated to preserving the central coordinating Worldwide Internet Assigned Numbers Authority www iana org functions of the global Internet protocol number assignment domain name assignment Other industrial Ethernet organizations provide recommendations and support these standards organizations but they do not define standards Internet Suite of The IETF is an IT organization that takes care of the TCP IP suite This organization TCP IP manages the evolution of protocols such as TCP IP UDP SNMP HTTP and FTP Standards Requirements for Internet Hosts Communication Layers Ed RFC 1122 STD 0003 October 1989 RFC 1122 IETF Network Working Group R Branden Modbus Industrial Modbus Application Protocol Specification Modbus IDA Version 1 1a June 2004IEC PAS Application Protocol Standard 31006929 8 2007 481 Standards and Considerations TIA EIA 568 A TIA EIA 568 A is one of the first cabling standards It was developed jointly by TIA Standard and EIA to define the wiring system for voice and data networks as
272. es OFS Services Communication with the PLC OFS supports multiple devices multiple communication protocols multiple clients access to devices and variables by address or by symbol access to the server in local or remote mode a notification mechanism that enables values to be sent to the client only when these values change state automatic determination of the size of network requests depending on the device type service availability via both the OLE automation and OLE custom interfaces compatibility with OPC Data Access standards both version 1 0A and 2 0 OFS supports two modes for exchanging data with the PLC default classic polling mode push data mode where data is sent at the initiative of the PLC Push data is recommended when changes of state are infrequent OFS offers the following services reading and writing of variables in one or more PLCs present on one or more different networks a user friendly configuration tool that explains the parameters needed for the server to function efficiently a tool enabling parameters to be modified online to maximize utilization flexibility the ability to use a list of symbols for the PLC application a browser interface that provides a graphical understanding of the accessible devices and their associated symbols a list of specific device dependent items that enables functions such as status start stop of the PLC and alarm supervision to be executed OFS opera
273. es the PLC is a Quantum 140 CPU65150 with an embedded Ethernet port The CPU logic scan times vary Modbus client response times are tracked with respect to six Modbus server response times lt 1ms 10 ms 20 ms 50 ms 70 ms 100 ms 420 31006929 8 2007 Modbus Client Performance At a CPU Scan Time of 200 ms 10 CPU Cycles o Communications Completed The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 200 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 1 1 2 1 1 1 1 1 2 3 1 1 1 1 2 2 4 1 1 1 2 2 3 5 2 2 2 2 3 3 6 2 2 2 2 3 4 7 2 2 2 3 3 4 8 2 2 2 3 4 5 9 3 3 3 3 4 5 10 3 3 3 4 5 6 11 3 3 3 4 5 6 12 3 4 3 4 5 T 13 4 4 4 4 6 7 14 4 4 4 5 6 8 15 4 4 4 5 6 8 16 4 5 4 6 7 9 17 5 5 5 6 7 9 31006929 8 2007 421 Modbus Client Performance At a CPU Scan Time of 100 ms CPU Cycles 8 10 Communications Completed 12 The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 100 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 1 1 2 1 2 2 1 2 2 3 1 2 2 2 3 3 4 1 2 2 2 4 4 5 2 2 2 3
274. esources issues network hardware Check hubs switches or routers if applicable for network traffic congestion or possible network broadcast storms If available monitor the error logs on the network hardware NIC For wireless connections use the network configuration to check the signal strength on the end device Note Specific tools are available to perform automatic testing of a cable These tools test for correct cable type selection pin connection etc For details on brands and models see Physical Layout chapter see p 27 350 31006929 8 2007 Troubleshooting Slow Connection Troubleshooting Problem category Topic Cause and Actions Physical check cable see note Check cable integrity and conformance to proper cabling requirements category 3 5 etc If an entire network in a large switched environment is still affected significantly after you check all logical connections disconnect entire network segments at the central backbone location and monitor the traffic until it is normal In this manner you can pinpoint the specific site building closet switch port cubicle end device or cable that is problematic network hardware Check the hub switch or router link lights for network traffic issues Under normal circumstances these indication lights are solid See the device vendor documentation for interpreting blink patterns Check the maximum n
275. esponse Time Time ms 16000 14000 12000 10000 8000 2000 40 Number of Registers 80 120 The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 500 CEV300200 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 651 33333 4244 66667 8351 333333 644 66667 4191 333333 8244 666667 138 16 701 33333 4644 66667 9151 333333 669 66667 4391 33333 8644 666667 138 32 754 66667 5071 33333 10004 66667 696 33333 4604 66667 9071 333333 138 64 861 33333 5924 66667 11711 33333 749 66667 5031 33333 9924 666667 138 100 981 33333 6884 66667 13631 33333 809 66667 5511 33333 10884 66667 138 31006929 8 2007 473 Gateway Performance 174CEV30020 Serial Server Response Measurements with One Request Timeout Test Setup The following charts show the time it takes to get responses from a certain number of requests sent to devices connected on the serial side of the 174CEV30020 gateway when the system experiences a failure of one communications request e g a disconnected serial device The failure results in a 1000 ms timeout of the initial request followed by one retry of the request Note One request failure increases the response
276. ess or report on the completion of a process Modbus messaging lets you initiate communications only when they are required making more efficient use of your network and device resources For details see p 179 Global Data The global data service allows a device to publish data to a group of devices on the network Devices in this distribution group can be configured to subscribe to the published data The global data service should be used when a device contains status information that more than one other device on the network needs to receive The publishing device uses multicasting to efficiently send information across the network to its distribution group For details see p 197 158 31006929 8 2007 Services Overview Faulty Device Replacement Time Synchronization Electronic Mail Notification The FDR service allows a central device the FDR server to store configuration parameters for remote devices on the network If a remote device fails the server automatically passes the stored configuration parameters on to a replacement device so that it can operate using the same configuration parameters as the failed device The replacement is accomplished without manually configuring the parameters The FDR service should be used for all devices that are connected to an automation network It reduces the need for service personnel to keep configuration records on hand and it prevents human error in entering the
277. et switching Network security issues Hardware component selection Open systems Standards interpretation by different vendors Network component selection Industrial plant environment and conditions Network shielding from noise and interference Physical network implementation in an industrial setting Operational priorities redundancy quick recovery Safety issues associated with the failure of automation controls Industrial Control Professionals Control device interaction Industrial installation requirements Data transfer speed requirements Recovery and redundancy needs Ethernet technology requirements Transparent Ready service selection Transparent Ready services see p 153 Open system environment requirements Open system communications issues Integration of products from multiple vendors System design and protocols System security issues 31006929 8 2007 23 Transparent Ready How this Guide Is Organized Summary Physical Planning Design and Installation Transparent Ready Services A Transparent Ready system comprises two key elements e the Ethernet network over which the devices exchange application data e the services that enable the transactions that happen on the network The three chapters that follow contain stand alone discussions of the major topics you will need to consider as you design a new Transparent Ready system or maintain an existing system
278. et network e the number of devices on the network the more devices the more likely collisions become e the length of the network the greater the chance for collisions e the packet length or MTU size a larger packet length takes longer to transmit thus increasing the chance for a collision The larger the frame size the more chance for a collision Switches when properly designed into the network structure are the key to avoiding network slowdowns due to collision or congestion Intelligent switches create less network traffic by sending data only to the destination that requires it They can also filter out bad packets preventing them from being forwarded further Switches also divide a network into separate shorter domains that each carry less traffic Full duplex switches see p 59 which allow transmission of data in both directions can increase bandwidth and completely eliminate collisions on the segments where they are used Schneider Electric recommends the use of full duplex switching in automation networks Performance on a shared network deteriorates when more devices or applications that require more data are added Increased collisions can be the result of too many end devices or too much traffic on the network For example actual throughput on a moderately loaded 10 Mb s Ethernet network is approximately 35 of capacity which is about 2 5 Mb s after figuring for packet overhead interpacke
279. ethods to decrease or neutralize EMI The following table shows methods appropriate for each type of coupling Methods Galvanic Inductive Capacitive Radiation Wave Coupling Coupling Coupling Influence Influence Grounding xX Electrical Isolation X Balancing Circuits X X xX Transposition of Outgoing X X X Return Lines Placement of Wires X X X Placement of Devices X X X Shielding X X X Filtering X X X X X Cable Selection X X xX Xx Wire Layout X X X X X Note The two most efficient methods for decreasing EMI are shielding and wire layout Both methods are described in this chapter 490 31006929 8 2007 Standards and Considerations Make sure you take the appropriate measures to e reduce the transmission of electromagnetic disturbance from interference sources e limit the spread of any electromagnetic disturbance Types of There are two main types of electromagnetic interference Electromagnetic e low frequency LF Interference e high frequency HF LF interference is encountered chiefly in conducted form such as conduction in cables It often has a long duration over several dozen milliseconds and in some cases may be continuous harmonic The conducted energy can be high and can result in the malfunction or even destruction of connected devices The frequency range is lt 1 5 Hz HF int
280. ettings in your Internet options In this case a security error in the status bar at the bottom of the Web browser window indicates this problem access control on Modbus If this is the case you see either Check the Schneider device to make sure your IP is listed as a designated IP for communications with the device question marks in the data fields or e an error indicating that the Modbus device can not be reached 31006929 8 2007 363 Troubleshooting 4 4 SCADA HMI System Slow Response Time Troubleshooting Slow Response Time SCADA HMl Troubleshooting Problem Category Topic Suggestions Determine the cause of the delay Determine if the delay is on write traffic or read traffic Send a device operation command and measure the interval between the command transmission and the device reaction Determine ls the delay in data writing or response reading ls there a difference between digital and analog data reading and writing Note Determine the device reaction from physical observation of the actual device not from the status display on the SCADA HMI system Determine if the delay is SCADA based or server based With a separate PC tool send a single request to the server and measure the response time Separate read and write requests should be sent for each data type the SCADA system reads e A fast response from the PC and a slow response from
281. evice Input to Local Output ms 140CPU65150 v2 0 10 ms 20 ms 50 ms 100 ms 200 ms Embedded Ethernet Port Scan Scan Scan Scan Scan v3 1 1 device 13 25 60 118 207 8 devices 13 25 60 118 209 16 devices 14 26 61 119 219 32 devices 21 33 69 130 233 31006929 8 2007 397 I O Scanner Performance 140CPU65150 The 140CPU65150 used for the following measurements is at version 2 0 with a with 140NOE771x1 Ethernet communications module at version 3 5 140NOE771x1 Ethernet Module 250 32 devices 200 4 150 4 1004 H 50 4 1 8 devices 0 i T 50 100 PLC Scan Time ms 150 200 The curves above show that the response times for all devices remain within 5 to 7 ms of each other for 1 8 16 and 32 devices The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Local Output ms 140CPU65150 v2 0 10 ms 20 ms 50 ms 100 ms 200 ms NOE771x1 v3 5 Scan Scan Scan Scan Scan 1 device 14 25 58 110 212 8 devices 15 26 59 111 213 16 devices 17 28 60 113 216 32 devices 19 30 62 115 219 398 31006929 8 2007 I O Scanner Performance 140CPU43412A The 140CPU43412A used for the following measurements is at version 2 0 with a with 140NOE771x1 Ethernet communications module at version 3 5 140NOE771x1
282. evice or equipment component s that is capable of being influenced by EMI Susceptible equipment has a low immunity level to EMI 31006929 8 2007 489 Standards and Considerations Coupling Mechanisms Ways to Decrease EMI Coupling is the spreading of EMI from its source to other susceptible equipment or devices There are five types of coupling mechanisms Coupling Mechanisms Description Galvanic Coupling through a common circuit Inductive Coupling through a magnetic field Capacitive Coupling through an electric field also called electrostatic coupling Radiation influence Coupling through an electromagnetic field Wave Influence Coupling through an electromagnetic field Interference can be transferred in a conductive guided energy form such as along a wire or through air unguided radiated energy Interferences are normally found together as line guided and radiated interference In general the same physical laws of energy transfer in electromagnetic fields apply to coupling interference The installation of an Ethernet for industrial application requires that you understand electromagnetic interference coupling mechanisms contributing influences and proper preventive measures before you begin to install Some of the ways you can decrease EMI and increase EMC in your installation are described in this chapter Depending on the type of coupling interference you can use various m
283. ew 3 15 Gateway Bridge Systems At a Glance Overview This section describes gateway and bridge systems What s in this This section contains the following topics Section a Topic Page Gateway and Bridge Overview 305 Gateway and Bridge Operation 309 304 31006929 8 2007 Services Overview Gateway and Bridge Overview Summary Operation A gateway allows devices on one network to communicate with devices on a separate network by converting the protocol on one side to the protocol on the other Gateways also known as bridges are used in an Ethernet system to convert from one type of network to another e g coaxial Ethernet to twisted pair token ring to Ethernet The following illustration shows protocol A on one side and B on the other with a message going from one side to the other Gateway Conversion of protocol A to protocol B Network A Network B Gateways can be grouped into 3 different types based on how devices are enabled on the 2 connected networks to communicate as follows e gateway without protocol conversion e gateway with protocol conversion e gateway using shared memory read and write 31006929 8 2007 305 Services Overview Gateway without Application Protocol Conversion A gateway without protocol conversion is able to take a message from the source network and pass the same message onto the destination network without modifyi
284. following services are available in a hot standby system Service Description Modbus Client Running in both primary and standby Only the first section of PLC application is running in the standby to trigger Modbus client requests Modbus Server Running in both primary and standby Requests to the standby PLC are processed by the standby CPU Modbus write data may be overwritten by the hot standby data transfer 1 0 Scanner Running in primary stopped in standby Global Data Running in primary standby may send some maintenance messages at start up but does not publish or subscribe to data FTP TFTP Running in both primary and standby SNMP Running in both primary and standby SMTP Running in both primary and standby e mail messages in the standby can be triggered only in first section of PLC application the only section running NTP Running in both primary and standby primary Ethernet communications module sets the clock in the primary CPU standby Ethernet communications module sets the clock in the standby CPU The NTP clock is not transferred between primary and standby CPUs Web Embedded Running in both primary and standby as independent services and FactoryCast The faulty device replacement service see p 205 is not available because the DHCP server is not available If there is a changeover from the primary to the standby PLC the IP swapping function automatically a
285. for noncritical notifications such as maintenance reminders or production reports 220 31006929 8 2007 Services Overview Security Additional Service Requirements An optional login password which is authenticated by the SMTP mail server to verify if the client is authorized to send emails can protect each email message To establish password protection you can use a subset of the SMTP service extension for authentication RFC 2554 This extension allows the client to authenticate prior to sending messages Also the SASL a method for adding authentication support to connection based protocols includes a command for identifying and authenti cating a user to a server and for optionally negotiating protection of subsequent protocol interactions As a result of this negotiation a security layer is inserted between the protocol and the connection When enabled both the login and the password are encrypted To provide additional security the site s email installation can change the TCP port number from the default setting of 25 The notification service only provides an email client in the Ethernet module The client sends electronic mail notifications To enable recipients to receive these messages the site where the Ethernet module is installed must have an email server such as Lotus Notes Microsoft Exchange or Linux SendMail The client connects to the email server to distribute the mail to its recipients 31
286. formation about shielding Administration 11 Explains the identification recording and documentation of a generic cabling system 494 31006929 8 2007 Standards and Considerations ISO IEC 11801 Conformance for Cabling Installations The final ISO IEC 24702 standard will borrow the following chapters from standard ISO IEC 11801 e Chapter 7 Link and Channel transmission classes for balanced cabling and fiber optic e Chapters 7 8 and 9 Component transmission performance for balanced cabling and fiber optic It will also add the following information based on industry requirements e A modification to the cabling structure specifications in the ISO IEC 11801 Chapter 5 e Environmental classification There is some limited information included in the ISO IEC 11801 Chapter 10 e Suitable components e Potential new concepts The ISO IEC 11801 standard defines conformance for cabling installations as follows For a cabling installation to conform to this International Standard the following applies a The configuration shall conform to the requirements outlined in clause 5 b The interfaces to the cabling shall conform to the requirements of clause 9 c The entire system shall be composed of links that meet the necessary level of performance specified in clause 7 This shall be achieved by installing components which meet the requirements of clauses 8 and 9 according to the design parameters of clause 6 or by a syste
287. fter three retransmissions the socket is reset and a new ARP is issued The loss of an Ethernet packet can switch off the health bit unless there is sufficient time to reissue the packet and receive an answer before the health time out period has expired The retry time for a lost or corrupted packet varies with different versions of the product Early versions retried at 800 ms 600 ms 1 5 s and 3 s Newer versions base their retries on the previous response times but in a good system approximately 50 ms 800 ms and 1 5 s can be achieved 176 31006929 8 2007 Services Overview Response Times The I O scanner system response time depends on e the CPU scan time e the time for the scanned device to respond to the request e the activation time for the scanned device for a new input or output O Scanner Ethernet TCP IP Response time Hub J Input Device Output Device The following chart illustrates the performance of a Quantum I O scanner round trip from the field input to the CPU and back to the output Delay in field device 1 rep rate Delay sending Delay in field a new a ae New field Input available in End of CPU New request New request Response Start of next CPU input communications scan sent at field back at PLC scan response adapter device taken into CPI Delay sending Delay in field 1 CPU scan 1 rep rate new requests device S pV
288. g Code The degree of protection is defined by the IEC 60529 standard This standard describes an protection fo international classification system that uses the letters P for ingress llowed by two or three digits This IP code defines the effectiveness of the seal on electrical equipment enclosures against the intrusion of solid foreign objects such as dust tools fingers etc The first leftmost digit in the IP code indicates the degree to which persons are protected against contact with moving parts excluding smooth rotating shafts as well as the degree to which the equipment is protected against the entry of solid foreign objects into its enclosure First Digit Degree of protection Solid objects 0 no special protection 1 Protection from a large human body part such as a hand and from solid objects greater than 50 mm in diameter It has no protection from deliberate access 2 Protection against fingers or other objects not greater than 80 mm in length and 12 mm in diameter 3 Protection from entry by tools wires and other solid objects with a diameter or thickness greater than 1 0 mm 4 Protection from entry by solid objects with a diameter or thickness greater than 1 0 mm 5 Protection from the amount of dust that would interfere with the operation of the equipment 6 Dust tight enclosure The second digit of the IP code indicates the degree of protection the equipment has
289. ge Registers Time 1 2151 33 3644 663333 5351 33 2144 67 3591 336667 5244 67 138 16 2151 33 3994 663333 6101 33 2144 67 3766 336667 5619 67 138 32 2151 33 4367 333333 6901 33 2144 67 3953 003333 6019 67 138 64 2151 33 5114 996667 8501 33 2144 67 4326 336667 6819 67 138 100 2151 33 5954 663333 10301 33 2144 67 4746 336667 7719 67 138 31006929 8 2007 477 Gateway Performance Serial Devices with 500 ms Response Time 16000 14000 12000 a i 2 m 10000 ne E v 5 E 5 6000 Ge 4000 5 2000 0 60 80 100 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 200 CEV30020 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 2151 33 5744 663333 9851 33 2144 67 5691 336667 9744 67 138 16 2151 33 6094 663333 10601 33 2144 67 5866 336667 10119 67 138 32 2151 33 6467 333333 11401 33 2144 67 6053 003333 10519 67 138 64 2151 33 7214 996667 13001 33 2144 67 6426 336667 11319 67 138 100 2151 33 8054 663333 14801 33 2144 67 6846 336667 12219 67 138 478 31006929 8 2007 Standards and Other Considerations for Industrial Ethernet Networks At a Glance Overview What s in this C
290. gement system parameters with a network management system Telnet a device connected to a person configuring the operating by a user parameters of a serial to Ethernet bridge network with a direct connection Before selecting a service make sure that the devices involved in the data transfer support the desired service If a device does not support the selected service you need to make another service choice Choosing another perhaps less optimized service does not mean that the interaction between the devices cannot be achieved but only that the use of the network and device resources may not be optimal Once you have selected the service record it in the list of plant communications Once all services are selected interactions between like devices using the same service may be combined This may not be appropriate for all interactions e g FTP to transfer files for one purpose cannot be combined with a separate FTP transfer but may be beneficial for others For example using Modbus messaging to transfer the status of 10 different items can be combined into a single transfer Perform a system performance evaluation to be sure that the combination of all data transfers does not overload any service or device An overload may result in lower performance from a service or a complete failure of the data transfers Your network must either be designed to support the services you select or if the network is alr
291. gies ISDN is one example of this cost effective technology When used as a backup routers can be configured to reroute traffic automatically if other WAN lines fail ISDN supports data transfer rates of 64 kb s There are two types of ISDN e BRI a basic service comprises two 64 kb channels and one D channel for transmitting control information e PRI for users with requirements for greater capacity comprises 23 B channels and 1 D channel U S or 30 B channels and 1 D channel Europe 62 31006929 8 2007 Planning and Layout Packet Switching Packet switching involves sharing resources at a service provider The service provider allocates portions of a line or of virtual circuits for the use of your enterprise Packet switching breaks up the packets and labels them individually sends them sequentially over the network by the most expedient route and reassembles them at the destination It is more efficient and cost effective for the carrier making the cost to the user less expensive than dedicated services The most common examples of packet switched WAN technologies are frame relay ATM and MPLS Frame relay which is based on packet switching technology supports data transfers rates of T 1 1 544 Mb s and T 3 45 Mb s Frame relay can provide a cost effective solution for industrial applications i LJ Plant A Frame Relay Switch Fast Packet Network 4 Relay Switch l l Ti
292. gister Number of requests in queue with overloaded requests 8 1 CPU scan Quantum NOE non read write Number of requests in queue register with overloaded requests 4 1 CPU scan Quantum embedded Ethernet port Number of requests in queue with overloaded requests 16 1 CPU scan Communication q Tor Product Number of Number of Multiple Requests 2 us Requests TCP Sockets per Socket Messaging Quantum NOE read write 4x 8 CPU scan per 64 per NOE yes register NOE module module Quantum NOE non 4x register 4 CPUscanper 64 per NOE yes NOE module module Quantum Embedded Ethernet Port 16 CPU scan 64 yes Premium TSXP571xx 4 CPU scan yes Premium TSXP572xx 8 CPU scan yes Premium TSXP573xx 12 CPU scan yes Premium TSXP574xx 16 CPU scan yes Premium TSXP575xx 16 CPU scan yes Advantys 4 yes ENT V1 4 ENT V2 4 Momentum unlimited 16 no 1 20 CPU scan max for all NOEs and embedded ports 324 31006929 8 2007 Services Overview Modbus Messaging Client Response Times Summary The Modbus messaging client response time is part of the total Modbus messaging system response time There are two methods for determining the Modbus client response times e considering the entire Modbus messaging system client and server as one unit e calculating the system component times separately In the first case the total system response time from client request to server response is measured The
293. h an embedded Ethernet port After the service is configured it receives a list of devices to scan and memory zones where it can read and write in the remote devices It then begins to exchange data with each remote device Each entry in the I O scanner configuration runs independently even if multiple entries exchange data with a single remote device E 3 A o E jejje 2 gt gt TINUTI o 9933092990000000008 POWER METER POWER METER ec mmi oo POWER METER 8 ol ole oii e e mmga eo 1 a controller 2 an output device 3 a reading device A A 31006929 8 2007 169 Services Overview Service Operation Each independent information exchange is represented by a separate entry in the I O scanner configuration table The following flow chart illustrates how the I O scanner executes one information exchange Puc Run D y An ARP is issued to receive the remote device MAC address and open a TCP connection to the remote device SYN SYN ACK etc Exchange is both read and write Write exchange Send Modbus FC23 Send Modbus FC3 Send Modbus FC16 Send FC3 in the first request then FC16 in the next request FC23 not supported error Receive Modbus response with data Set Modbus health bit
294. hapter This appendix illustrates some I O scanner response times for Premium and Quantum systems that use industrial Ethernet This chapter contains the following sections Section Topic Page A 1 Premium PLC I O Scanner Response Times 374 A 2 Quantum PLC I O Scanner Response Times 387 31006929 8 2007 373 I O Scanner Performance A 1 Premium PLC I O Scanner Response Times At a Glance Overview The system response time curves illustrated in this section are based on measurements made on Premium PLCs that are scanning Momentum 170 ENT 110 00 devices Momentum was used because it provides the shortest response times for Ethernet applications approximately 5 to 8 ms Three different types of response time scenarios are presented What s in this This section contains the following topics ion Section Topic Page Premium I O Scanner Response Times Remote Input to Remote Output 375 Premium I O Scanner Response Times Remote Input to a Local Output 379 Premium I O Scanner Response Times PLC Memory to Remote Output 383 374 31006929 8 2007 I O Scanner Performance Premium I O Scanner Response Times Remote Input to Remote Output Measurement Setup The set of curves below illustrates Premium PLC response times when a signal is sent from a remote input module through the PLC to a remote output module Response Time The signal is
295. hapter This appendix provides additional material in support of the standards and planning information presented in Chapter 2 see p 27 This chapter contains the following topics Topic Page Standards and Organizations 480 Electromagnetic Compatibility 489 Copper Connector Standards Activities 493 Conforming to Standards 494 Transparent Ready Industrial Ethernet Conformance 496 31006929 8 2007 479 Standards and Considerations Standards and Organizations Standards Organizations Several standards organizations develop generic cabling requirements The Electronics Industries Alliance EIA and the Telecommunications Industry Association TIA develop and approve the LAN cable standards Other groups develop network standards that affect cabling specifications Standards Organization WebSite Description Area of Influence EIA www eia org An association of seven electronics industry sectors U S and and groups including the TIA CEMA ECA EIG Canada GEIA JEDEC and EIF TIA www tiaonline org An association of mostly U S and Canadian U S and companies that provides communications and Canada information technology products materials systems distribution services and professional services IEC International www iec ch International standards and conformity assessment Worldwide Electrotechnical Committee body for all
296. he following designated Ethernet signals M12 Ethernet Signal 1 Transmit TD 2 Receive RD 3 Transmit TD 4 Receive RD 31006929 8 2007 89 Planning and Layout Fiber Optic Connectors Development of Fiber Connectors SC Connectors ST Connectors LC Connectors MT RJ Connectors Several types of fiber connectors have been developed The fiber connector FC was the first connector to use a 2 5 mm ceramic ferrule The ferrule is the connector cap that surrounds the end of an optic sheath and creates the connection The straight terminus ST connector was introduced slightly later It had the same ceramic ferrule but was easier to insert because of its lock The subscriber connector SC appeared next and has gained popularity The mass termination MT and the MT RJ connectors are the most recent developments in the connector industry The SC connector is becoming the most popular connector in use with fiber cable It has a square front and is easier to install in confined spaces The ST connector was introduced by AT amp T It is the most frequently found connector in installed fiber optic networks since it has been the most popular connector to use in recent years It has a barrel shape that looks similar to a BNC connector with a bayonet like lock that makes it fast and easy to insert The LC connector resembles a small SC connector It was developed by Luce
297. he Ethernet Timeout This is too long for most system users to wait for a response so the number of devices per bridge needs to be reduced However with a faster serial device response time calculating the total best case bridge response would use the formula 5 ms request 50 ms serial device response 20 ms response 50 ms 125ms request For 8 Modbus devices with 2 requests each the best case response time would then be an acceptable 16 x 125 ms 2 0 s If the time out of a request is included calculating the worst case bridge response time gives the required value for the Ethernet timeout field Ethernet time out timeout of a serial line request x number of serial line retries x number of requests sent to the bridge If this time out calculation is not used and the value in the field is too slow the failure of one or more serial devices can cause Ethernet requests to other serial devices to time out due to the delay caused by the incorrect value 31006929 8 2007 339 Services Overview 340 31006929 8 2007 Troubleshooting At a Glance Introduction What s in this Chapter This chapter describes general troubleshooting steps and provides methods for identifying problems It also provides tables that help you identify and resolve problems This chapter contains the following sections Section Topic Page 4 1 About Troubleshooting 342 4 2 Network
298. he Ethernet services supported by a Twido CPU and a Twido Ethernet communications modules Service TwidoPort 499TWD01100 I O Scanner Modbus Server x Modbus Client x Global Data 31006929 8 2007 315 Services Overview Advantys STB Distributed I O Service TwidoPort 499TWD01100 FDR Server FDR Client BootP Client X Time Synchronization E mail Notification Web Embedded Diagnostics FactoryCast Web Server SNMP FTP Server TFTP Server Telnet Server X 1 Device receives and sends Modbus messages as a gateway The following table lists the Ethernet service supported by an Advantys STB standard Ethernet network interface module NIM Service STBNIP2212 O Scanner Modbus Server X Modbus Client Global Data FDR Server FDR Client BootP Client x Xx Time Synchronization E mail Notification Web Embedded Diagnostics x lt FactoryCast Web Server SNMP FTP Server x Xx TFTP Server Telnet Server 1 Device can be scanned by the I O scanner as it implements the Modbus server 316 31006929 8 2007 Services Overview Altivar ATV 38 58 Variable Speed Drive Power Logic Gateways Bridges The following table lists the Ethernet service supported by the VW3A58310 card in the Al
299. he connection at the end of the cable shielding provides a metal to metal bond that circles the sheath a full 360 degrees You can use metal cable clips to fasten mesh shielding and get complete 360 degree contact Check that no paint or insulating coating exists between contact surfaces 31006929 8 2007 505 Earthing Grounding Procedures Connection e Avoid using poor connections from the cable sheath to a metal earth bus bar or Notes plane e Remove any insulating plastic tape between the cable shielding layer and the sheath e Avoid using long cable shielding lengths Shielding loses its effectiveness if the cable is too long To optimize the effectiveness of shielding provide a large number of intermediate connections to the earthing frame This diagram shows a cable with multiple connections to the earthing frame 506 31006929 8 2007 Earthing Grounding Procedures Cable Shielding Connection Options Two Ways to Ground a Cable Shield A CAUTION Exposure to low voltage When grounding a cable shield at only one end there is a potential difference between the shielding and the ground connection of the unearthed end e Avoid contact Failure to follow these instructions can result in injury or equipment damage There are two ways you can ground a cable shield e create earthing connections at both ends of the cable e create earthing connections at only one end
300. he device complexity manufacturers may choose to implement private MIBs that provide additional information specific to their device The SNMP protocol transports and exchanges all information using UDP UDP s small and simple packet size reduces the network load However extensive monitoring can cause increased network load Since the introduction of SNMP protecting network management information has become an increasingly important issue In SNMPv1 requests and replies are sent in clear text exposing variables to hackers MIB writers discovered that some data type definitions required more precision SNMPv2 addressed these issues by improving the authentication of the message source protecting these messages from disclosure and placing access controls on the MIB database However some security aspects still remained vulnerable SNMPv3 framework augments the original SNMPv1 and v2 specifications with additional security and administration capabilities 31006929 8 2007 245 Services Overview TFTP Service TFTP Service Summary TFTP is a simple client server protocol that may be used instead of FTP to transfer files It uses UDP port number 69 and is implemented on top of the UDP transport layer With TFTP most of the features of a regular FTP are removed It can perform only read and write operations from to a remote server it cannot list directories and it has no provisions for user authentication or security T
301. he files become too large you can store them on separate Web servers and store only the links to those files on the FactoryCast device The illustration shows how a FactoryCast web server accesses documents 2 g 1 aFactoryCast module where links to a central Web server are stored 2 the central Web server where documents are stored 3 a Web client can access the desired documents through the FactoryCast module 232 31006929 8 2007 Services Overview FactoryCast Web Server Operation Alarm Viewer The alarm viewer is a ready to use alarming system comprising a password protected alarm page viewable in a Web browser and function blocks inside the device used to add alarms to the alarm system The diagnostics buffer in the device is the source of the alarms on the Web page This system can be used e to process device alarms display acknowledgment and deletion that can be managed automatically by the system e by the user application employing diagnostic elementary function blocks EFBs The alarm viewer is a Web page that contains the following information for each alarm its state the type of associated EFB its geographical area the dates and times of the occurrence removal of a fault Graphic Data The graphical data editor can be used to create customized screens showing Editor animated plant data These views are created in a Web based tool accessed from the FactoryCast device using a library of grap
302. he graph to evaluate the system response time is chosen on the I O scanner processor being used and type of system field input to field output For 16 devices and a 20 ms CPU scan time the system response time from field input to field output is 49 ms For Advantys devices the response time needs to be calculated using the system formulae to take into account the field device delays Problem A Momentum I O device is being polled by e a Quantum I O scanner reading three separate blocks of data e a Premium PLC reading a block of data using a Modbus messaging request If a SCADA wishes to access the Momentum is it able to read data How can the system be changed so the SCADA is able to read data Answer The Momentum I O device can open only four TCP sockets simultaneously The I O scanner from the Quantum holds the TCP sockets open the I O scanner always hold the sockets open the Premium PLC opens a single socket when the Modbus read request is triggered A total of four sockets is open on the Momentum The socket being used by the Premium could be closed after the transaction if the Momentum requests that it be closed but the Momentum is not designed to do this Because the maximum number of sockets open the open socket request from the SCADA is rejected To enable the SCADA system to open a socket one of the other sockets must be closed This cannot be done on the Premium but the Quantum I O scanner can close one if its socke
303. he more esoteric it is set to become MAC layer bridge that uses network layer methods to determine a network s topology Protocol that implements a specific routing algorithm Table stored in a router or some other internetworking device that keeps track of routes and in some cased metrics associated with those routes to particular network destinations Message sent from a router to indicate network accessibility and associated cost information Routing updates are typically sent at regular intervals and after a change in network topology real time publish subscribe Enables the transfer of data and the transfer of state over unreliable protocols like UDP IP SASL simple authentication and security layer Used to identify and authenticate a user to a server can also protect further transmissions by inserting a security layer 534 31006929 8 2007 Glossary SCADA ScTP SDH segment segment delay segmentation server session shared Ethernet signal loss SLIP smart wiring hub SMF SMS supervisory control and data acquisition Software that interfacing with a programmable logic controller gathers and analyzes information used to monitor and control commercial equipment screened twisted pair Cabling with two conductors wound around each other to lessen crosstalk a braided shield like STP and an extra outer braid for added protection synchronous digital highway Signal stan
304. he number of lost packets e reduce network traffic e eliminate half duplex links e reduce electrical noise These changes only reduce packet loss They do not eliminate the problem 31006929 8 2007 367 Troubleshooting Using a Packet Capture Tool Overview Tool Types Tool Capabilities In an ideal system all devices would detect and report the exact cause of network errors but this is not always possible A device can be unable to detect or report an error If the device indicates only a general error instead of a specific error you can use an Ethernet packet capture tool to monitor the Ethernet packets and determine the specific error and its cause This allows you to determine the actual error and layer IP TCP or application on which the error occurs so you can take corrective action We do not recommend packet capture tools for general plant maintenance but they are well suited for diagnosing intermittent problems or problems that occur during device installation These tools capture network packets and display them on the screen The tools also save the packets in a file that you can analyze later Ethernet packet capture tool types e physical layer These expensive tools capture physical signals on the wire and logical data on the upper layer e hand held These tools analyze only layers 2 3 and 4 They are not quite as expensive as physical layer tools and are rugged enough for field
305. he primary CPU 2 The standby CPU 3 Racks of remote I O modules Hot standby provides redundant control of a plant via physical I O The system changes from the primary CPU to a standby CPU if the primary unit is unable to control the physical I O This can occur due to the failure of the primary system s e power supply e CPU e RIO adapter e RIO link A traditional hot standby system does not switch control from the primary to standby for any of the following reasons e failure of Modbus Plus or Ethernet links e inability of the primary system to communicate to a remote device via a network link other than I O via the RIO network These restrictions present problems for a system that relies on SCADA system communications or plant control via network communications In the event of a communications failure of the primary PLC the system does not automatically switch over to the standby unit to re establish communications even if each PLC is capable of controlling the I O 31006929 8 2007 295 Services Overview Communication centric Systems In acommunication centric system the integrity of the communications between the hot standby system and a device in the plant system may be important enough to justify a hot standby changeover In this type of system the standard Quantum hot standby operation must be modified so that the communications to the remote device are monitored and a changeover is forced if communications f
306. her network These two tasks are not synchronized so system response time is slow and inconsistent Gateway Network B Network A oj EEA Internal register area 2990009000000090900 15000000000065000000 308 31006929 8 2007 Services Overview Gateway and Bridge Operation Queues If devices on the source network are sending requests to the gateway faster than they can be processed on the destination network a message queue forms inside the gateway Depending on the actual gateway the queue may have a fixed maximum length Once the queue is full the gateway either crashes or returns a new message request with an error response Consider the response time of the destination network and the effect of a timeout as it pertains to the queues inside the gateway of the destination network To help prevent a queue from growing to unreasonable lengths requesting devices should not send a retry of a message before the gateway has processed the message they must wait until either a response or error message is received before sending the retry Devices must keep track of the number of messages sent to the gateway for which they have not received answers this number needs to be kept low The queue affects the system response time If a source device sends a command to the destination network device the command must wait in the queue
307. hernet cable CAT 5 5e or 6 are recommended 100 m or less e basic cable making tools see p 108 31006929 8 2007 109 Planning and Layout Making an Ethernet Copper Cable Making an Ethernet Fiber Cable Step Action Comment 1 With the stripper tool strip 2 inches of the plastic jacket at one end of the cable 2 Hold the base of the plastic jacket with one Keep colored pairs of wire together hand and spread the wires apart with the and in the same order brown blue other hand Do not allow the wires to become green and orange untwisted inside the jacket 3 Hold the wires tightly at the point where they Make sure your cutters are aligned enter the plastic jacket Line up your cutter straight across the wires to ensure that across the separated wires about 0 5 in from all the wires will be cut at the same the edge of the plastic jacket 0 5 in length 4 Make a clean cut across the four wire pairs Maintain a firm grasp on the jacket as you do this Do not allow the wires to untwist inside the jacket as you cut 5 Grasp the RJ45 jack firmly between two If the wires resist your efforts keep fingers and slide the wires into the jack Be working them forward until you have sure to follow the pinout color code them fitted into the jack where you specifications for the type of cable you are want them Do not release the wires making while you are fitting them 6 Work the wires fo
308. hernet systems 80 A access server in an Ethernet WAN 65 ACR attenuation crosstalk ratio 514 actual earth 95 administration cabling 111 alarm viewer in a FactoryCast Web server 233 application layer in the TCP IP model 125 application synchronization for global data 202 asynchronous services in an OPC factory server operation 262 attenuation ISO IEC 11801 performance parameter 512 attenuation of crosstalk ratio ISO IEC 11801 performance parameter 514 back up watchdog in a SCADA system 294 balance ISO IEC 11801 performance parameter 515 blocking in SCADA communication 280 BootP troubleshooting 360 BRI ISDN options 62 bridge in an Ethernet system 60 troubleshooting 365 broadcast domains in an Ethernet system 57 building backbone 36 bus topology 43 C cabinet distributor 42 cabinets creating equipotential bonding for 98 cable construction for Ethernet 110 cable crimper for building Ethernet copper cables 108 110 cable cutter for building Ethernet copper cables 108 110 cable labeling standards 111 31006929 8 2007 543 Index cable routing between buildings 104 between cabinets 104 cable run recommendation 101 cable shielding connecting to a metal surface 504 cable stripper for building Ethernet copper cables 108 110 cables components labeling 111 cabling 100Base FX fiber optic specifications 86 10Base FL fiber optic specifications 86 administration
309. hic objects The objects may be customized for color PLC variables to display labels etc The following graphic objects are provided analog and digital indicators horizontal and vertical bar charts boxes for displaying messages and entering values push button boxes functions for displaying trends After the screens are created they can be stored in the FactoryCast device for future use or to be reused in customized Web pages 31006929 8 2007 233 Services Overview The following illustration shows some of the objects that can be used to develop a graphical screen Stop 234 31006929 8 2007 Services Overview Devices that Support FactoryCast Web Server Services Device Quantum 140NOE77111 140NWM10000 Premium TSXETY110WS TSXETY5103 TSXWMY 100 Micro TSXETZ510 31006929 8 2007 235 Services Overview 3 10 FactoryCast HMI Web Server At a Glance Overview The section describes the FactoryCast HMI Web service and how to use it for real time plant diagnostics and control What s in this This section contains the following topics Section Topic Page FactoryCast HMI Web Services 237 Devices that Support The FactoryCast HMI Web Service 241 236 31006929 8 2007 Services Overview FactoryCast HMI Web Services Summary FactoryCast HMI Web Service Operation The FactoryCast HMI Web server exte
310. his section reference their ongoing work in cable and connector standardization 68 31006929 8 2007 Planning and Layout Mechanical Requirements Introduction Shock Requirements Vibration Requirements Mechanical requirements apply to any mechanical electrical or electronic component or assembly of components Tests and ratings for mechanical compliance with standards include the following shock vibration tensile strength flexing crush impact The following table shows the recommended allowable degrees of shock for an industrial Ethernet Environment Shock Limits Reference Light Industrial 15 9 11 ms IEC 60068 2 27 Environmental testing Part Environment Light Duty 3 axis in both 2 Tests Test Era and guidance Shock directions EN 60068 2 27 Heavy Industrial 20 g 11 ms IEC 60068 2 27 27 Environmental testing Environment Heavy Duty 3 axis in both Part 2 Tests Test Era and guidance Shock directions EN 60068 2 27 Vibrations are defined as mechanical oscillations produced by movements of a member or body from its rest position at regular or irregular time periods Vibration can result in equipment damage loss of control in equipment and reduced efficiency in machine operation The following table shows the recommended allowable degrees of vibration for an industrial Ethernet Environment Shock Limits Reference Light Industrial 29 10 500Hz _
311. hneider Electric recommends the RJ45 connector for use in office and light industrial environments see p 67 and the M12 4 pole with D coding circular connector for use in heavy industrial environments The following table lists specifications for the industrial Ethernet copper connectors recommended by Schneider Electric Environment Connectors General Specifications Reference Light Industrial RJ45 IEC 60603 7 and Light Duty Pin assignment ISO IEC 8802 3 TIA EIA 568B Pinout Color Coding TIA EIA 568B Shielded Heavy Industrial M12 4 pole IEC 61076 2 101 Heavy Duty with D coding shielded As defined in the Ethernet IEEE 802 3 and the ISO IEC 8802 3 standards the connector specified for the Ethernet 10Base T and 100Base TX physical layers is the RJ45 copper installations RU registered jack is defined in the United States Code of Federal Regulations The RJ45 is a connector used to terminate twisted pair cables A typical RJ45 connector is shown here Schneider Electric recommends shielded RJ45 connectors in office and light industrial environments and shielded CAT 5E cables for 10Base T and 100Base TX industrial Ethernet networks If you have devices that use shielded jack connectors and are externally grounded the cable shield is grounded at both ends of the cable 31006929 8 2007 87 Planning and Layout RJ45 Pins and Ethernet Signals The RJ45 connector has
312. iagnostic window which holds the server and communication status Most of the communication protocols used by OFS are half duplex after sending 1 request the server waits for the answer before sending the next request The exception is XWAY for Unity or PL7 PLCs With half duplex networks the only way to speed up the communication is to open more than 1 channel between the sender and the receiver You can open between 1 and 16 channels for each device and you can configure that number either statically with the OFS configuration tool or dynamically with the specific MaxChannel The value that gives optimal performance depends on the PLC being accessed i e the number of requests it can process per cycle and the communication card being used most notably on Concept PLCs To obtain this data refer to the PLC and communication card documentation Note The multi channel function is not significant for Unity Pro or PL7 PLCs that use an XWAY full duplex network and with serial Modbus drivers single channel only on any PLC types On half duplex networks a parameter can be used to send several requests to a device simultaneously the higher the value the better the performance for communication with the device 266 31006929 8 2007 Services Overview Runtime Architecture for Unity OFS SCADA a Simple Example Sample Architecture Runtime System Options Key System Characteristics Product Vers
313. ibutors or machine distributors provide connectivity to the devices located inside a cabinet in a machine or on the plant floor The following table shows the environmental requirements based on the location of the devices Device Location Environmental Requirement Inside a cabinet Light industrial environment In a machine Light or heavy industrial environment On plant floor Heavy industrial environment Inside the cabinets the configuration is star or daisy chain using devices with two Ethernet ports The next topic see p 43 presents some typical network topologies and how they can be developed in an Ethernet environment These topologies are usually deployed beginning with the plant floor distributor Device outlets DOs are located inside the cabinet If the devices are located on the plant floor there can be either a DO or a new distributor for devices in the field called a field distributor or FD 42 31006929 8 2007 Planning and Layout Understanding Basic Network Structure Summary Bus Topology The physical layout or topology of a network consisting of cables components and devices can be structured in any of several architectures bus star daisy chain ring dual ring e mesh Illustrations of each type of layout are included Each layout has its advantages and disadvantages as shown in the tables Switches and hubs are mentioned in conjunction with the network ar
314. ication protocols with network protocols This is a Microsoft Windows standard dynamic host configuration protocol Communications protocol that assigns IP addresses to devices on the network based on BootP 31006929 8 2007 521 Glossary distributed A system in which each station or node in the network performs its own processing processing and manages some of its data while the network facilitates communications between the stations DNS server domain name server service A service that translates a domain name into an IP service address the unique identifier of a device on the network DO device outlet dongle A short network cable that connects a PCMCIA adapter to a network cable drop cable A cable that allows connection and access to the trunk cable in a network a k a attachment unit interface AUI cable or transceiver cable DSL digital subscriber line A high speed Internet connection using normal telephone wires DVMRP distance vector multicast routing protocol A routing protocol used to support multicast that uses distance as measured in routing hops to determine a packet s optimal path E EGP exterior gateway protocol Exchanges routing information specifically routing tables between two hosts on a network EMI electromagnetic interference Occurs when a device s operation is disrupted or encapsulation EOS ERP degraded by the field of another nearby device Wrapping a data set
315. ices are 8 ms longer initially as scan time increases the difference in response times becomes smaller The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from PLC Memory to Scanned Device Output ms TSXP57304M v2 0 ETY5103 10 ms 20 ms 50ms 100 ms 200 ms v3 1 Scan Scan Scan Scan Scan 1 device 11 21 52 102 202 8 devices 13 24 54 104 204 16 devices 17 29 59 109 209 32 devices6 19 30 60 110 210 386 31006929 8 2007 I O Scanner Performance A 2 Quantum PLC I O Scanner Response Times At a Glance Overview The system response time curves illustrated in this section are based on measurements made on Quantum PLCs that are scanning Momentum 170 ENT 110 00 devices Momentum was used because it provides the shortest response times for Ethernet applications approximately 5 to 8 ms Three different types of response time scenarios are presented What s in this This section contains the following topics ion Section Topic Page Quantum I O Scanner Response Tmes Remote Input to Remote Output 388 Quantum I O Scanner Response Tmes Remote Input to Local Output 392 Quantum I O Scanner Response Times Local Input to Remote Output 396 31006929 8 2007 387 I O Scanner Performance Quantum I O Scanner Response Tmes Remote Input to Remote Output Measurement The set of
316. icious purposes IP masquerading allows only the connection at the firewall or router to be seen on the Internet in order to hide a protected IP address space medium attachment unit A device used to convert signals from one Ethernet medium to another A transceiver is a MAU manufacturing execution system A computerized system that aids in managing data and communications for production flow 528 31006929 8 2007 Glossary MIB MICE Mil MMF MPLS MSTR MT RJ MTU multi port repeater multicast management information base A database of network parameters used by Simple Network Management Protocol SNMP and Common Management Information Protocol CMIP to monitor and change network device settings It provides logical naming for all information resources on the network that pertain to network management mechanical ingress climatic environmental An international standardization effort by a collaborative group of experts from IEC TC65 TIA TR 42 9 and CENELEC TC215 WG1 to establish environmental standards for industrial Ethernet media independent interface IEEE 802 3u standard for fast Ethernet MII is the fast Ethernet equivalent of AUI in 10 Mb s Ethernet it allows different types of fast Ethernet media to connect to a fast Ethernet device via a common interface multi mode fiber A cable that passes light instead of electronic pulses It supports point to point connections only over a ma
317. ick resolution you can cycle the power ona suspect device but you should first evaluate whether the cycle interferes with plant operations Cycling the power may temporarily restore communications to the device but it will not identify or correct the problem 31006929 8 2007 343 Troubleshooting General Problem Identification Before You Begin Problem Identification Gather as much information as you can about the characteristics symptoms and behavior of an issue before you attempt to troubleshoot Problems that initially seem to be network issues can turn out to be application issues mismanaged end devices or facility related Ask these basic questions when you start to troubleshoot e Are symptoms regular or intermittent e How widespread is the problem Does it affect one device several devices or all devices Are the affected devices located in the same area of the site e Are symptoms related to one or all applications services What other applications services run at the same time e When was the first occurrence of the problem e Do occurrences coincide with irregular or non standard network activities that would not initially seem to cause problems e Have you changed network hardware or software components recently Have you added end devices to the network recently e Could maintenance work moving cleaning cable management electrical work etc affect network operations Keep the answer
318. ideo data programming data and Web pages at the same time on the same network Transport Layer The transport layer provides end to end data transfer It is responsible for reliable information exchange There are different transport layer protocols the main one being TCP UDP is another protocol that may run in the transport layer it is used for applications that require a fast transport mechanism Unlike TCP UDP does not have the ability to divide long messages and reassemble their packets in the correct order on the other side and it is unable to send retries The application that is sending the message is required to make sure that the messages are sent in their entirety or if required retransmit the message 31006929 8 2007 125 Planning and Layout Internetwork Layer Network Interface Layer The internetwork layer separates the physical network from the layers above IP is the most important protocol in this layer IP is a data oriented protocol used by source and destination hosts for communicating data across a packet switched internetwork IP is a connectionless protocol that does not assume reliability from the lower layers It is sometimes referred to as the Internet layer or network layer IP does not provide flow control or error recovery These functions need to be provided at either the transport layer if you use TCP or the application layer if you use UDP The message unit in an IP network is called a
319. iew Favores Tools Help e 30 40 Address hetp i64 69 103 153 secure system plecfg htm co uks E customize Links FreeHotmal Windows Media Windows El QUANTUM LOCAL RACK Home Controller Status Ethernet Statistics RIO Status Graphic Editor Data Editor FactoryCast Schneider Automation Inc 1998 2001 31006929 8 2007 227 Services Overview Data Editors The data editor function can be used to create tables of animated variables for real time read write access to lists of PLC data The variables to be displayed can be entered and displayed symbolically S_Pump 234 or by their address MW99 These variables support write access only if this option has been enabled using FactoryCast configuration software A second password must be entered and verified when writing a value to a variable You can create various animation tables containing specific application variables to be monitored or modified and save them in the Ethernet TCP IP module The following illustration shows a data editor 4 Premium Diagnostic Equipment Microsoft Internet Explorer 4 10j x Fie Edt View Favorites Tools Help a Hesk gt A A Dsearch Favorites CBristory D 4 A a D Address http 139 160 174 73 securefsystemjplectg htm z co us CustomzeLnks E Free Hotmal Windows Meda Windows
320. ifies the services provided by each Web service class Web Server Web Services Class Maintenance Monitoring and IT Link Diagnostics Optional D Active Web User Website Autonomous execution of User defined states User documentation Server update specific services e g alarm notification by E mail exchange with databases calculations SOAP XML client server C Configurable PLC variables editor Communication Web Server Remote commands service diagnostics User Web pages State of internal SOAP XML server product resources B Standard Remote device Device description Device diagnostics Configuration of Web Server software update Data viewer network parameters Remote auto tests and Ethernet communication services Device documentation A No Web No Web services Server Ethernet The Ethernet communication services provided by a product are defined in 3 Communication Service Classes classes Each class is identified by a number e Class 10 standard Ethernet communication services e Class 20 Ethernet communication management services network level and product level e Class 30 advanced Ethernet communication services Transparent Ready products can provide 8 types of Ethernet communication services Modbus TCP messaging I O scanning Faulty device replacement Network management SNMP Global data Bandwidth management Time synchronization NTP Email event notificat
321. il Notification z Web Embedded Diagnostics X Xx xX FactoryCast Web Server 3 SNMP X xX xX xX x FTP Server X X xX TFTP Server x x Telnet Server X xX x3 x3 1 Device receives and sends Modbus messages as a gateway 2 Multicast filter support for global data 3 For factory diagnostic purposes only 318 31006929 8 2007 Services Overview 3 17 System Performance Evaluation At a Glance Overview This section describes how to obtain the system response times for each of the chosen communications within your plant It also describes the checks that should be done on the devices and the network so that the overall message load on a device does not exceed its abilities and so that the overall network load does not cause communication delays What s in this This section contains the following topics Section Topic Page System Communications 320 Modbus Messaging Response Times 320 Modbus Server Response Times 321 Modbus Messaging Client Response Times 325 I O Scanner Systems 329 Total Load on Devices 331 System Performance Solutions 332 Gateway Response Times 337 31006929 8 2007 319 Services Overview System Communications Summary The performance of Ethernet architecture is linked to the hardware and the application services used and to the parameters set for these services H
322. imes overlap and bolt the ends of the metal cable troughs together If this is not possible install a wide braided strap joining the two troughs under every table as shown in the diagram below 102 31006929 8 2007 Planning and Layout Recommen dations for Cable Routing inside a Cabinet oahwWh Follow good wiring guidelines Follow the cable run recommendations in this chapter Always try to separate and segregate interfering and sensitive components and cables in different cabinets In small cabinets partitioning signal types by sheet metal panels bolted to the chassis may be sufficient In large cabinets allocate one cabinet for every class of components When possible lay the cables in metal ducts DODO mo e O a MY _ iit Q power low level to power components mains actuators sensors 31006929 8 2007 103 Planning and Layout Cable Routing e Use metal for all ducts that are longer than 3 m outside and e Bolt the ends of metal cable troughs and conduits onto metal cabinets to make between satisfactory connections as shown in the diagram below Cabinets Cable Routing There is usually a lack of equipotential bonding between two buildings The two Outside and ground connections one at each building should be connected All cable runs Between between two buildings must be doubled up with a large section of equipotential line Buildings 35 mm
323. in a protocol header for example Ethernet data wrapped in a specific Ethernet header before network transit Also a method of bridging dissimilar networks where the entire frame from one network is simply enclosed in the header used by the link layer protocol of the other network Ethernet over SONET SDH Transfers Ethernet signals in SONET SDH enterprise resource planning A software system for businesses that manages planning manufacturing and sales also can include finances and human resources modules 522 31006929 8 2007 Glossary Ethernet A 10 or 100 Mb s CSMA CD baseband LAN that may run over thin coax thick coax twisted pair or fiber optic cable The IEEE standard 802 3 defines the rules for configuring an Ethernet network F fault tolerance FDDI FDR fiber optic cable file server filtering firewall firmware FOIRL A network s ability to deter a failure on one part of the network from disrupting other network services It increases network integrity and uptime Examples include redundant power supplies on transceivers hubs and switches simple or doubled redundant optical or copper ring topologies fiber distributed data interface ANSI standard for using fiber optics to transmit data at up to 100 Mb s over a network Originally specified for fiber lines FDDI standards can also be used on short lengths of twisted pair cable a k a CDD faulty device replacement A tran
324. ine modifications from Unity Pro imply saving the STU application file so that OFS Unity Pro XL is synchronized with the right version of the application Product Version Comments Unity Pro M L XL 2 0 for the application modifications Unity Pro XL v2 0 for the PC server mode VijeoLook v2 6 includes the correct version of OFS Monitor Pro v7 2 without access to the structured variables 31006929 8 2007 273 Services Overview 3 13 SCADA HMI At A Glance Overview This section describes the operation and design of a SCADA or HMI system It focuses on the use of the Modbus TCP IP communications protocol between the SCADA system and the end devices The information is not specific to a particular SCADA system or HMI package the concepts described apply to most packages on the market but terms and techniques may vary between packages What s in this This section contains the following topics Section Topic Page SCADA HMI 275 I O Server to Field Device Communications 277 SCADA Communications to Field Devices Socket and Request Usage 281 I O Server and Display Client Communications 285 Schneider Product Implementation Details 286 274 31006929 8 2007 Services Overview SCADA HMI SCADA HMI Models Standalone Model SCADA and HMI systems are represented by two models standalone and client server The standalone SCADA HMI m
325. ing 0 00 eee ett eee 354 Modbus Messaging and I O Scanner Troubleshooting 356 SNMP Troubleshooting 000 c cece cette eee 358 Telnet and FTP Troubleshooting 2 e eee eee ees 359 Faulty Device Replacement BootP Troubleshooting 00 360 SMTP Troubleshooting 0 0 0 c cece eee 361 Time Synchronization NTP Troubleshooting Table 362 Web Troubleshooting Table 0 0 cece eee eee 363 SCADA HMI System Slow Response Time Troubleshooting 364 Slow Response Time SCADA HMI Troubleshooting 364 Bridge Troubleshooting 0 cece ete teens 365 Lost Packet Troubleshooting 0 00 e eee eee eee ee 366 Using a Packet Capture Tool 0 0 c ects 368 Packet Capture Troubleshooting 0 000 e cece eee eee 369 CeCe ee ee ee er ee ee ee ee ere eee 371 I O Scanning Response Times 200eee ee eeeee 373 Premium PLC I O Scanner Response Times 0000 eee e eee 374 Premium I O Scanner Response Times Remote Input to Remote Output 375 Premium I O Scanner Response Times Remote Input to a Local Output 379 Premium I O Scanner Response Times PLC Memory to Remote Output 383 Quantum PLC I O Scanner Response Times 000 00 eee eaee 387 Quantum I O Scanner Response Tmes Remote Input to Remote Output 388 Quantum I O Scanner Response Tmes Remote Input to Loc
326. ing begins to forward a packet once it is received which can cause network disruption if the packet is bad e Store and forward switching waits for the entire packet to arrive and checks the packet for corruption before forwarding it out the correct port This prevents corrupt packets from being forwarded across the entire network A store and forward switch also stops a corrupt packet at the first switch it reaches after it has been corrupted The time delay for the process is minimal less than 1 ms on an industrial network Store and forward switches are recommended by Schneider Electric for automation networks Transceivers change the physical medium in most of the cases that transition is between copper and fiber optic A bridge has been used to connect two LAN segments with different protocols Ethernet Token ring or to connect two LANs using Ethernet addresses However because bridges supply lower throughput performance lower port density higher transport cost and less flexibility switches are recommended for use over bridges An Ethernet router is also known as gateway or default gateway Routers connect two separate networks They create or maintain a table of the available networks and use this information to determine the best route for a given data packet from the source network to the destination network Routers can be used to break up broadcast domains A layer 3 switch is a router implemented in hardware
327. ion SMTP 20 31006929 8 2007 Transparent Ready The following table specifies the services provided for each Ethernet communication service class Service Ethernet Communication Services Class Modbus Messaging I O Scanning FDR SNMP Global Data SMTP Bandwidth Management NTP 30 Direct read write of I O 20 Periodic read write of I O Configuration of the list of devices scanned Automatic control update of device parameter configuration Use of the MIBlibrary by an SNMP manager Publica tion and subscrip tion of network variables Event notifica tion by email Monitoring of local load level Device clock synchro nization Automatic assignmentof IP address and network parameters Control update of configuration and product parameters by the user Product detection of by an SNMP manager Read Write data words Local assignmentof IP address Verification of duplicate IP addresses 31006929 8 2007 21 Transparent Ready Choice of Transparent Ready Products The services provided by a Transparent Ready product are identified by a letter defining the level of Web service followed by a number defining the level of Ethernet communication service For example e A class A10 product is a product with no Web service and standard Ethernet services e A class C30 produ
328. ion to load new firmware custom Web pages etc FTP transports and exchanges all information using TCP By default FTP uses TCP port number 20 for data transport and TCP port number 21 for control The client initiates an FTP connection by connecting to the control port on the server The server responds by connecting the data port back to the client After the connections are made file transfer can take place In Transparent Ready devices FTP may be used for different purposes depending on the device For example only firmware and custom Web pages are accessible on Transparent Ready CPUs through the FTP server CPU program files cannot be accessed an FTP client PC an Ethernet switch a PLC with FTP server connections a PLC program with no path to the FTP server HTML Web page files akon The client must provide a username and password in order to read or write files on the server However the transmission of this authentication information is done in simple text therefore it can be obtained by inspecting the content of the messages between the client and the server The transmission of files over or outside of a network is a major concern when firewalls are implemented to control access and information flow Therefore unless the FTP port is open in the firewall this type of communication is blocked For information on how to open ports on firewalls refer to the firewall documentation see p 150 or co
329. ions The following runtime example is for simple architectures where the PLC application does not need on line modifications XVM files Symbols for OFS a VijeoLook is the best choice for this type of architecture Only one PC is used to run both the SCADA and OFS software The maximum number of PLCs on a system like this is five On Ethernet TCP IP only you can locate the XVM symbols file on another PC instead of the one that runs the SCADA and OFS This option lets you centralize the resources on one PC that can be easily backed up This implementation may be necessary when the system is integrated in larger architecture e The runtime system needs the Unity Pro XVM symbols file to be compatible with OFS The symbols file is exported in Build mode by Unity Pro and must be copied on the PC that is used to run the system A symbols file is needed for each PLC application e The SCADA OFS XVM files system runs on one PC e OFS accesses the data in the PLC in real time Any discrepancies between the running application and the local symbols file on the PC initiates signature checking In accordance with QoS for OFS the communication stops or switches to a bad quality service You need to manually update the PC with the correct symbols file in order to have consistency between the symbols file and the application running in the PLC Product Version Comments Unity Pro M L XL 2 0
330. ions check the dial tone at the RJ 11 jack with a standard analog phone NIC Make sure the traditional or PCMCIA network card is properly seated in the machine Test the card s performance by swapping one NIC for another network hardware Check the hub switch router wireless access point RAS server and other network hardware for power and port link lights for proper activity typically solid or blinking green Check uplink cable connectivity for stacked devices For a suspect hub port or switch port substitute an identical port after you have completed logical checks See the vendor s documentation for device specific information Logical check OS When working remotely at an unfamiliar hotel conference center customer site etc verify with your network administrator that your access method is supported and allowed through the remote site s network When using a VPN or dial up connection over an existing Internet connection verify the performance of the connection by using the Internet browser before you attempt to troubleshoot the client or server When using a dial up connection make sure the appropriate dial up network configuration is installed and configured At the DOS prompt use the ping command to check for the basic level of network connectivity for replies or timeouts For security reasons ICMP ping requests are sometimes blocked Discuss this issue with the network administrat
331. is aborted or closed before data transfer Some devices report an error code but most report a timeout or general error message In the absence of a reported error you can only discover this event with a packet capture program Client Errors Topic Issue Incorrect MAC An entry for the server IP MAC address combination must be in the ARP cache of the device that address sends the client request The client device usually generates this entry but it can be incorrect usually when e a failed device is replaced with a device with a different MAC address for the same IP address e two devices swap IP addresses and create different IP MAC combinations for each device e a client device saves its ARP table to flash memory but does not refresh the table after a subsequent power up Client overload An overloaded client system is not able to send requests This is most true for systems in which the user controls the trigger request time as ina PLC system This issue is not common where the system like SCADA or HMI schedules requests Candidates for overload are e the device s Modbus system a limit on the number of TCP sockets the device can have open A new socket may need be opened for the transmission of a new Modbus request This error is normally indicated by an error message or a long delay before the request transmission 356 31006929 8 2007 Troubleshooting Server Error
332. is section discusses some important additional topics to consider when incorporating Transparent Ready capabilities into your network design What s in this This section contains the following topics Section Topic Page Internet and IP Technologies in an Automation Environment 122 Open System Interconnection Model 124 The TCP IP Model 125 Transparent Ready Model 127 IP Addresses and Classes 130 Multicasting Considerations 135 Multicast Filtering 136 Network Management 137 Routing 139 Introduction to Remote Access 141 Remote Access Types 142 Network Access Methods 144 PLC Connected to the Internet 147 Security Issues 149 31006929 8 2007 121 Planning and Layout Internet and IP Technologies in an Automation Environment Network Design Considerations Why Use Ethernet Transparent Ready provides a wide range of devices and strategies with which you can develop a network infrastructure that supports your plants communications The openness and flexibility of a Transparent Ready Ethernet network require that you make some decisions about your system as you design it These decisions include how the network will be used what communication services it needs to support what paths the network will take response time throughput requirements redundancy and resilience requirements The challenge in today s world is agility not only in the technology itself but in your willingness to adopt and refine collab
333. istributor Most industrial sites consist of one or more separate plants These different plants may have control rooms from which the plant is operated or motor control centers where the MCC and control devices are located Typically the plant distributor is located in either the control or MCC room The environmental requirement for a plant distributor is either office or light industrial As mentioned previously the plant distributor is usually located either in the control or MCC room the plant distributor is connected to the other distributors such as the office plant distributor and the plant floor distributor The office plant distributor manages the terminal outlets for the plant office These terminals are used to connect printers computers and video conferencing devices The plant floor distributor manages equipment on the plant floor In most cases these two distributors are located in either an office or a light industrial environment The office plant distributor is usually managed and maintained by IT personnel The plant floor distributor is managed by personnel responsible for the cabinet distributors also called field distributors or machine distributors The traffic between the plant floor distributor and the plant distributor is isolated with a router and secured with a firewall Typically cabinets contain devices with a low number of ports or connections such as switches Cabinet distributors also called field distr
334. ists of multiple elements This requires the creation of an earthing main conductor and the attachment of all metal structures and objects in the building to that main conductor The CBN is then connected to an exterior earthing electrode system that terminates in the earth Earth plane A mesh grid made of welded reinforcing rods cast into the concrete slab or placed in a false floor with the grid made of copper conductors An earthing ring bus is the most effective form of earthing main conductor It is typically installed in the basement or ground floor of buildings that contain telecommunications systems The metal sheaths of cables conduits cabinets and heating and water pipes are connected to the earthing main conductor using the shortest path The diagram below shows an earthing system with an earth plane and earthing ring bus 96 31006929 8 2007 Planning and Layout Procedure The following procedure describes how to create an earthing system for a building The installation of an earthing system is the first step to creating an EMC environment see p 489 Step Action 1 Create an earth plane and a ring bus 2 Interconnect all metal structures in the building Metal structures include metal structural elements welded concrete reinforcements metal pipes and ducts cable troughs power conduits conveyors metal doors and window frames and gratings The interconnection forms a common
335. it is not possible to program over this type of gateway Gateway Network A Request Network B Mapped request Viapped response Response t read read A write write A connect N A program N A 31006929 8 2007 307 Services Overview Gateways Using Some gateways can present a shared memory area to devices on both networks Shared Memory Devices on both networks can read or write data from this memory area and can share data although no message is actually passed from one network to the other A device on the source network can write data to the shared memory area anda device on the destination network can then read the data from that memory area A gateway of this type never actually passes a message from the source network to the destination network No programming is required and no complex messages are transferred Only data using the memory types presented in the shared memory area can be transferred For example if only words are supported the transfer of individual bits is not supported This gateway decouples the two networks Because it does not wait for a response from the destination network before it responds to the request this gateway can respond very quickly with data from its shared memory area Although this gateway appears to be very fast the actual response time is slow because all data must be handled twice once into shared memory and once out to the ot
336. itecture 238 calculation functions 240 connected to a relational database 240 device support 241 HMI tag database 239 hybrid architectures 238 information management levels 239 operation 237 FactoryCast Web server service alarm viewer 233 configuration software 231 device support 235 graphical data editor 233 hosting 231 far end crosstalk ISO IEC 11801 performance parameter 514 fast Ethernet 55 fault conditions for the Transparent Ready I O scanning service 176 faulty device replacement 360 device support 207 service selection 159 when to use the service 206 faulty device replacement client 206 faulty device replacement server 206 FDR faulty device replacement 159 FEXT far end crosstalk 514 fiber optic 82 cabling types 83 technical description 82 field distributor 42 field level communication 155 Transparent Ready services 157 file transfer protocol Advantys STB device support 254 ConneXium device support 255 Micro device support 253 Momentum device support 253 Power Logic device support 254 Premium device support 251 Quantum device support 249 file transfer protocol service 243 firewall 150 advanced 150 setup 150 with Modbus filtering 150 flexing requirements 70 frames in an Ethernet system 55 FTP file transfer protocol 161 troubleshooting 359 function codes Modbus 182 G GARP multicast registration protocol 136 gateway in an Ethernet system 60 message q
337. itical notification 218 31006929 8 2007 Services Overview An Application Example Many industrial facilities are connected to numerous pump houses in remote locations that supply them with water These locations contain pumps valves and filters that require regular preventive maintenance based on the number of hours of operation Maintenance dates may change from month to month depending on the utilization of the pumps filters or valves Email notification to the maintenance crew when those maintenance limits are reached eliminates the need to travel to a remote pump house to check For example one of the pump filters has been in service for 1000 hours over a period of 3 months without being cleaned or replaced and now requires preventive maintenance Because the system has been configured to trigger a maintenance request after every 1000 hours of operation an alarm is sent out by the Ethernet module to the email server to notify the maintenance crew to clean or replace the filter in the pump house After the email server has processed the message and sent it to the company network the maintenance crew receives the email notification If the email server is set up to send messages to pagers or mobile phones an additional notification could be sent to the maintenance crew using these media 1 Ny p a a A
338. k device driver that it wants to be a member of a specified group The device driver maps the multicast IP address to a physical multicast address Group memberships are dynamic Members are able to join and leave a group anytime they want Senders need the multicast IP address only to send information regardless of whether or not any hosts are listening at that time When a host wants to join a multicast group it signals its intention to the router that sits on the same subnet 136 31006929 8 2007 Planning and Layout Network Management Summary Network Management Components SNMP Protocol MIB Private MIBs Setup ofa Network Management System Managing your network allows you to monitor who is on the network network traffic network traffic errors device errors Network management is accomplished by the use of a management system a protocol that allows the management system to communicate with the devices and end devices such as switches and routers that are configured to support the protocol SNMP has become the standard protocol for network management It comprises e an agent the software module for network management that resides in a device e a manager NMS that can query and get responses from agents and set variables in them e a managed device with a MIB A management information base MIB is a data base of managed objects such as broadcast messages sent and received or co
339. keeps the TCP socket open until the other end closes it or the NOE module reaches its TCP socket limit If one of these events occurs the NOE closes any socket that has no outstanding requests on it Newer NOE modules can send multiple requests down a single TCP socket Some older NOE modules may support only a single TCP socket per request and close the TCP socket after each exchange is completed 31006929 8 2007 185 Services Overview Modbus Client Operations in Premium Systems Limits Using Unity Pro or PL7 programming software an application on a Premium system can initiate Modbus client communications using the following Modbus client blocks e WRITE_VAR e READ_VAR e SEND_REQ e DATA_EXCH The Premium PLC limits the number of Modbus client communication blocks that can be triggered concurrently based on CPU type This limit applies to the total number of Modbus client request blocks per CPU and includes blocks triggered for the following messaging services Modbus TCP IP client Fipway Modbus serial Unitelway e Ethway If additional client blocks are triggered an error message is returned to the application program Modbus client requests are limited as follows Client family of processors Ethernet Communications Number of Requests Mechanism Unity Pro v2 0 CoPro ETY module or embedded port 80 Unity level 2 P57 xx ETY module 32 Unity level 4 TSX574 xx ETY module 64
340. lane supports e eight type 1 path requests served per CPU scan e four type 2 path requests served per CPU scan up to a limit of 20 requests Note To see the improvement you may need to adjust the SCADA package to make sure enough requests are being sent to the PLC 31006929 8 2007 191 Services Overview Modbus Server Operations in Premium Systems Premium Implementation Premium PLC systems implement a Modbus server in the PLC s CPU ETY cards or embedded ports pass Modbus requests to the CPU for processing The CPU limits the number of Modbus requests that the server can answer per CPU scan This limit includes requests from Fipway Unitelway Ethway Modbus TCP IP Modbus serial A Modbus busy exception occurs when the CPU receives more requests than it can handle during a CPU scan If this happens an exception response is sent back to the Modbus client that sent the request The following table shows the number of requests processed per CPU scan for different Premium PLC systems PLC Ethernet Communications Responses Mechanism per Scan Pre Unity v2 0 Unity Pro v2 0 CoPro ETY module or embedded 20 estimated port Unity level 2 P57 xx ETY module 20 Unity level 4 TSX 574 xx ETY module 20 PL7 level 2 TSX572 xx ETY module 8 PL7 level 4 TSX574 xx ETY module 16 Unity Pro v2 0 Unity CoPro embedded port 16 ETY module 20 Unity TSX P57304M E
341. larly to routers The switching engine can then route from one VLAN to another improving performance on the LAN Some limitations of VLANs include those on the number of broadcasts and Ethernet addresses and constraints on ports Wireless communication IEEE 802 1 1a b g allows mobile communications without the expense of cable runs or fixed location maintenance It does not replace wired networks it does allow a single device to access the network from various locations Wireless technology for industrial environments must create the same reliability performance and redundancy that exist today with wired networks 58 31006929 8 2007 Planning and Layout LAN Hardware Summary Hardware and Its Operation Layer Hubs Repeaters Switches An overview of the hardware used on a local area network is useful in planning a robust network for your industrial application The following discussion gives a brief overview and some recommendations for the LAN hardware you should use to construct a Transparent Ready industrial Ethernet application see p 77 The following table shows on which layer each hardware element falls according to the OSI model see p 124 Layer Layer Number Hardware Application 7 gateway If the gateway also converts protocol Network 3 routers gateways layer 3 switches Data link 2 switches Physical 1 hubs A hub is an active device with multiple por
342. le cable All nodes are considered equal and receive all transmissions on the medium Cc CBN common bonding network The interconnected metallic components that comprise an earthing system in a building Also known as an integrated ground plane 31006929 8 2007 519 Glossary CENELEC channel checksum CIDR circuit switching circuit switched network classless addressing coaxial cable collision collision detection communication server concentrator ConneXium CRC European Committee for Electrotechnical Standardization in Brussels The end to end data path between two nodes All cabling from one active device to another A redundancy check that typically adds up bytes to detect errors in a message classless interdomain routing Also known as classless addressing or supernetting A flexible method to allocate IP addresses less wastefully Maintaining a switch only while the sender and recipient are communicating A network that establishes a physical circuit temporarily until it receives a disconnect signal See CIDR An electrical cable with a solid wire conductor at its center surrounded by insulating materials and an outer metal screen conductor with an axis of curvature coinciding with the inner conductor The result of two network nodes transmitting on the same line at the same time The transmitted data are not usable so the stations must send again A delay mechanism employed
343. lementing the time synchronization service Any difference in accuracy is due to the I O modules used A traditional sequence of event recording system uses dedicated I O modules with special filtering systems The I O module time stamps the input as soon as it occurs and then begins to filter it If the input is determined to be noisy the event is discarded from the records The time synchronization service is based on normal PLC I O modules where the input is filtered inside the module before it is passed to the CPU as an event and recorded by a time stamp This filter before recording method results in less accuracy but it reduces costs because no special I O modules are required The cost advantage is based on the distribution of the time across an existing Ethernet network In a traditional system a GPS or DCF receiver must be connected directly to each I O module The cost of multiple receivers and the difficulty of running antennas for these devices outside the plant because GPS receivers require a clear view of the sky is much greater than the cost of a single receiver attached to a central NTP time server The Ethernet configuration requires only a single outside antenna system and uses the plant s existing Ethernet network 31006929 8 2007 215 Services Overview Schneider Devices Implementing Time Synchronization Service The TSXETY5103 and 140NOE77111 modules are the only Ethernet modules that support NTP prot
344. level communication 157 for synchronizing applications 157 global data 158 198 I O scanning 158 167 Modbus messaging 158 180 Momentum Ethernet communication device support 315 Momentum M1E device support 314 OPC factory server 257 Power Logic gateway device support 317 Premium CPU device support 312 Premium Ethernet communication device support 313 Quantum device support 312 simple network management protocol 244 Telnet 247 time synchronization 159 trivial file transfer protocol 246 troubleshooting 354 355 TSX Micro communication device support 314 Twido device support 315 used for applications 156 used for company level communication 156 used for field devices 156 used for supervision systems and PLCs 156 Web server 224 Web FactoryCast 160 shielded RJ45 copper connectors 87 shielded twisted pair cable characteristics 79 shock requirements 69 signal classification 99 simple network management protocol Advantys STB device support 254 ConneXium device support 255 Momentum device support 253 operation 245 Power Logic device support 254 Premium device support 251 Quantum device support 249 slow connections on an Ethernet system 351 SMTP for electronic mail notification 220 troubleshooting 361 SNMP for network management 137 for network management stations 156 simple network management protocol 161 troubleshooting 358 standards cable labeling 111 fiber optic cabling 82 for
345. levels of service within ISDN the one intended for larger enterprises Consists of 23 B channels and one 16 kbps D channel in the U S or 30 B channels and one D channel in Europe A dedicated computer that manages printers and print requests from other nodes on the network protocol Any standard method of communicating over a network Q QoS quality of service A performance specification for measuring and improving the transmission quality and service availability of a communications system R rapid spanning tree RSTP An enhancement of spanning tree protocol that cuts convergence time it reduces reconfiguration time and therefore restores service faster See spanning tree 532 31006929 8 2007 Glossary RARP RAS redundancy remote access remote control remote node repeater ring RIO adapter RIO link RIP RJ connector RMON RMON MIB reverse address resolution protocol A protocol used to convert a hardware interface address into a protocol address remote access server service A server that offers remote access to a Local area Network LAN most commonly by use of a telephone line The duplication of critical components in order to increase reliability Access to network resources not located on the same physical Ethernet where the physical Ethernet refers to an entire site network topology Form of remote access where a device dialing in assumes control of another netw
346. lity of a device at the MAC sub layer to identify the speed 10 or 100 Mb s and the duplex or half mode of a connection and to adjust it according to clause 28 of the IEEE 802 3u standard backbone bandwidth baseband LAN bit s BNC The main cable of the network The range of frequencies that a line transmission can carry The capacity of a digital channel is measured in bits per second bit s A local area network that uses a single carrier frequency over a single channel Ethernet uses baseband transmission Bits per second unit of transmission speed Bayonet Neill Concelman Standard connector used to link 10Base2 thin coaxial cable to a transceiver 518 31006929 8 2007 Glossary BootP BRI bridge bridge router bootstrap protocol A TCP IP network protocol that offers network nodes request configuration information from a BOOTP server node basic rate interface Of the two levels of service within ISDN the one intended for residential and small business use Consists of two 64 Kips B channels and one 16 kbps D channel for a total of up to 128 kbps of service A networking device that connects two LANs and forwards or filters data packets between them based on their destination addresses Bridges operate at the data link level or MAC layer of the OSI reference model and they are transparent to protocols and to higher level devices like routers Bridges connect networks that use dissi
347. llowing diagram ss EE es Ee ELEA ze Eo EE EE E E Problem Determine the response time of the SCADA system in each of the following cases Case One SCADA opens one socket and only sends one request at a time Answer In this scenario the SCADA only sends a new request when a response is received from the previous request This results in the formation of a queue in the SCADA The PLC has only one request to answer at the end of each CPU scan in which a response to the request is guaranteed at the end of each CPU scan In this case there will be 21 requests in the queue The SCADA sends the first request to the PLC the PLC sends a response back in 140 ms after which the SCADA sends the next request in the queue to the PLC Therefore the PLC takes 2 94 seconds to answer all 21 requests SCADA system response time is 2 94 seconds Case Two SCADA opens one socket but sends multiple requests to the PLC at the same time 31006929 8 2007 333 Services Overview Answer In this case the PLC has multiple requests to answer at the same time which may exceed its ability This results in the PLC taking multiple CPU scans to answer all requests The SCADA sends all 21 requests to the PLC and forms two queues in the PLC one for Ox and one for 4x From the information above you can see that the PLC has 11 requests in the 4x register and 10 requests in the Ox queue The NOE can process 8 4x requests and 4 other
348. lted directly onto the earth plane plate to provide high quality durable metal to metal contact Note Because of its excessive length the main green yellow earth conductor cannot generally provide HF quality earthing 98 31006929 8 2007 Planning and Layout EMC compatible Ethernet Wiring and Cable Runs Classification of In an industrial environment signals are classified into four categories according to Signals their EMC performance This classification is required to apply the cabling rules EMC Performance Class Sensitivity Interference Circuit or Device Example PLCs Transformers in the cabinet PCBs Contactors Regulators circuit breakers Cables connected Fuses to inputs and Switching power supplies outputs Class 1 or 2 cables Frequency converters carrying analog Variable speed drives signals DC power supplies Microprocessor clocks Cables connected to such components Power supply lines Power cables 1 Sensitive Signal is very Low level circuits with analog outputs sensitive Sensors Measuring circuits probes sensors etc 2 Sightly Signal is sensitive Control circuits connected to resistive loads Sensitive Can disturb class 1 Low level digital circuits cables Low level circuits with all or nothing outputs Low level d c power supplies 3 Slightly Signal disturbs class 1 and 2 Contr
349. m design and implementation ensuring that the prescribed performance class of clause 7 and the reliability requirements of clause 9 are met d System administration shall meet the requirements of clause 11 e Local regulations concerning safety and EMC shall be met The ISO IEC 11801 standard further states The link performance specified in clause 7 is in accordance with clause 6 installation The link performance is met when components specified in clauses 8 and 9 are installed in a workmanlike manner and in accordance with supplier s and designer s instructions over distances not exceeding those specified in clause 6 It is not required to test the transmission characteristics of the link in that case Conformance testing to the specifications of clause 7 should be used in the following cases e a the design of links with lengths exceeding those specified in clause 6 e b the design of links using components different from those described in clauses 8 and 9 e c the evaluation of installed cabling to determine its capacity to support a certain group of applications e d performance verification as required of an installed system designed in accordance with clauses 6 8 and 9 31006929 8 2007 495 Standards and Considerations Transparent Ready Industrial Ethernet Conformance Application Classes Application classes are defined by the ISO IEC 11801 standard Each application has a frequency range and every a
350. manage information Examples include e Ethernet wireless fiber optic copper and other media through which information is transferred e Ethernet frame the Internet protocol suite TCP IP SOAP and other protocols that transfer information e Java HTML XML and other language protocols that present the information Ethernet refers to the way that data accesses the network how the messages are framed for transmission and reception and the physical characteristics of the network topology cables connectors and infrastructure Industrial Ethernet is the commercial name adopted by the industrial automation market segment to refer to the use of Ethernet in an industrial environment The term is now so generic that other Internet technologies are included even if Ethernet itself is not present For example Ethernet is not used in an industrial wireless 802 11 communication but it is still considered an industrial Ethernet application A detailed analysis of industrial Ethernet see p 27 is presented in this manual in which the different characteristics and origins of Ethernet TCP IP and Modbus are explained 16 31006929 8 2007 Transparent Ready Industrial and Commercial Ethernet Comparison In an industrial control environment programmable logic controllers PLCs around the plant act as servers for the input and output I O modules PLCs may be interconnected by industrial fieldbuses further distributing
351. manent links and channels applications Supporting Optical Class applications are specified at referred to as Optical Class permanent links 10 MHz and and Optical Class channels respectively above 496 31006929 8 2007 Standards and Considerations Maximum This table shows the maximum channel lengths by cable category and class as Channel Lengths defined by the ISO IEC 11801 standard ISO IEC Maximum Channel Lengths by Cable Categories and Class Media Class A Class B ClassC ClassD ClassE ClassF Optical CAT 3 2 km 200 m 100 m CAT 4 3 km 260 m 150 m CAT 5e 3 km 260 m 160 m CAT 6 100 m 100 m CAT 7 3 km 290 m 180 m 120 m 150 ohm 3 km 400 m 250 m 150 m Cable 62 5 125 and 2km 50 125 mm Optical Fiber Singlemode 3 km The class D link performance limits are listed in Annex A of EN 50173 2002 and ISO IEC 11801 2002 The measurement limits are described in prEN 50346 2001 31006929 8 2007 497 Standards and Considerations 498 31006929 8 2007 Earthing Grounding Procedures At a Glance Overview This appendix describes procedures for earthing grounding What s in this This chapter contains the following topics Chapter Topic Page Well made Earthing Ground Connections 500 Making an Earthing
352. mber of Registers 80 100 The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 100 Timeout EGX400 Time to Complete All Requests 1000 ms 1 Retry Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 2185 33 2978 663333 3885 33 2178 67 2925 336667 3778 67 172 16 2185 33 3328 663333 4635 33 2178 67 3100 336667 4153 67 172 32 2185 33 3701 996667 5435 33 2178 67 3287 003333 4553 67 172 64 2185 33 4448 663333 7035 33 2178 67 3660 336667 5353 67 172 100 2185 33 5288 663333 8835 33 2178 67 4080 336667 6253 67 172 31006929 8 2007 465 Gateway Performance Serial Devices with 200 ms Response Time 10000 8000 6000 4 4000 4 a es ar 6 2000 4 Time ms 0 20 40 60 80 100 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Tlme 200 Timeout EGX400 Time to Complete All Requests 1000 ms 1 Retry Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 2185 33 3678 663333 5385 33 2178 67 3625 336667 5278 67 172 16 2185 33 4028 663333 6135 33 2178 67 3800 33
353. ments with One Request Timeout 452 446 31006929 8 2007 Gateway Performance EGX200 Serial Server Response Times Test Setup The following charts track the time it takes to get responses from a certain number of requests sent to devices connected on the serial side of the EGX200 gateway The performance is based on network baud rates of both 9600 and 19 200 and on the amount of data i e the number of registers requested The following legend describes the baud rate and number of requests sent as tracked in all four of the charts that follow Curve Number of Requests Baud Rate 1 16 9600 2 19 200 3 8 9600 4 19 200 5 1 9600 6 19 200 31006929 8 2007 447 Gateway Performance Serial Devices with 50 ms Response Time Time ms 7000 5 6000 5000 4 4000 3000 2000 1000 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 50 EGX200 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 250 8333333 694 1666667 1200 833333 244 1666667 640 83333333 1094 166667 187 5 16 300 8333333 1094 166667 2000 833333 269 1666667 840 8333333 1494 166667 187
354. milar protocols and that operate at the data link level or layer 2 of the OSI model They are often described as media access control level MAC layer bridges They do not carry out any interpretation of the information they carry When two LANs are successfully bridged together they become one effective LAN Various load balancing techniques have been developed to combat the problems of bandwidth limitation and the failure of any element on the network Bridges are increasingly used to control network traffic so that the rest of the network is not involved This boosts network performance and is also useful for security purposes A device that can provide the functions of a bridge a router or both concurrently A bridge router can route one or more protocols such as TCP IP and or XNS and bridge all other traffic broadcast A message that is sent out to all devices on the network broadcast A collection of devices that receive a broadcast sent on an Ethernet network The domain broadcast domain ends at a router positioned in the network If any device in a broadcast domain broadcasts information that information is received by all devices in the same domain it is not be received by devices connected through a router Brouter A device that routes specific protocols such as TCP IP and IPX and bridges other protocols thereby combining the functions of both routers and bridges bus ALAN topology in which all the nodes are connected to a sing
355. mium system 186 client limits ina Quantum system 185 client operations in a Momentum system 188 client operations in a Premium system 187 client operations in a Quantum system 185 client response times in a Momentum system 327 client response times in a Premium system 327 client response times in a Quantum system 326 client retry times 196 client services 182 183 client time outs 196 device support 184 Modbus TCP device implementation 180 response time 320 server communication limits 324 server operations in a Momentum system 194 server operations in a Premium system 193 server operations in a Quantum system 189 server operations with Concept 190 server operations with Proworx 190 server response times in a Premium system 193 server retry times 196 server services 182 183 server TCP socket limits 195 service selection 158 simple servers 195 troubleshooting 356 Unity server performance 191 550 31006929 8 2007 Index Modbus server 182 183 operations in a Momentum system 194 operations in a Premium system 193 operations in a Quantum system 189 operations with Concept 190 operations with Proworx 190 performance in Unity 191 response times in a Momentum system 322 response times in a Premium system 193 321 response times in a Quantum system 322 retry times 196 TCP socket limits 195 Modbus servers 195 modem in an Ethernet WAN 66 Monitor Pro implementation of th
356. ms and the PLC reads the data in next scan 50 ms The additional time is 150 ms The total system response time is 300 ms Note It is possible to calculate a slightly lower time if the actual timing of the other devices response and the CPU s scan are taken into account The response should arrive part way through a CPU scan so you can calculate just the remaining CPU scan time before the response is processed into the application This method is not recommended because the worst case should always be assumed You have no control over the synchronization of the two devices 31006929 8 2007 335 Services Overview Problem 6 Problem 7 Problem A 140CPU65150 Quantum I O scanner with an embedded Ethernet port ona PLC with a CPU scan time of 20 ms is polling five Momentum Advantys and a third party I O devices 15 devices in all The response time of the third party device is 100 ms What are the response times for each device type to read an input act on it in PLC code and write a responding output to the same device Determine how the response time changes if the CPU scan time increases to 100 ms Determine how the response time changes if the CPU scan time is 10 ms but the configured repetition rate is 50 ms Answer For the Momentum I O the response time of the field device is minimal The Momentum was used for the I O scanner performance graphs in the appendix see p 373 T
357. ms 100 ms 200 ms and 500 ms are measured as they communicate across a network through a 174CEV30020 Modbus to Ethernet gateway Network speeds of 9600 baud and 19 200 baud are considered Measurements are taken for both successful communications and for situations where a single request failure is experienced followed by a successful retry What s in this This section contains the following topics i Section Topic Page 174CEV30020 Gateway Serial Server Response Times 469 174CEV30020 Serial Server Response Measurements with One Request 474 Timeout 468 31006929 8 2007 Gateway Performance 174CEV30020 Gateway Serial Server Response Times Test Setup The following charts track the time it takes to get responses from a certain number of requests sent to devices connected on the serial side of the 174CEV30020 gateway The performance is based on network baud rates of both 9600 and 19 200 and on the amount of data i e the number of registers requested The following legend describes the baud rate and number of requests sent as tracked in all four of the charts that follow Curve Number of Requests Baud Rate 1 16 9600 19 200 9600 19 200 O o AJ OJN 9600 19 200 31006929 8 2007 469 Gateway Performance Serial Devices with 50 ms Response Time Time ms 7000 4 6000 4 5000 4 4000 4 3000 4 2
358. mum subscription of 2048 words e ETY4102 5102 and ETY4013 5103 e Premium and Quantum CoPro Ethernet port e NOE77101 11 31006929 8 2007 201 Services Overview Global Data Considerations Multicast Technology Application Synchronization The global data service is implemented using multicast technology see p 135 Multicast is different from broadcast and unicast technologies Broadcast sends information from one device to all devices on the network Unicast sends data from one device to another Multicast allows a device to send a single block packet of data to a predefined distribution group see p 199 Published data that is sent to a specific multicast IP address is forwarded by switches and routers only to devices in the distribution group that subscribe to that multicast IP address Multicast filtering see p 136 restricts the data from going to every device on the network and allows the distribution group to operate efficiently on an Ethernet network without disturbing other devices on the network Distribution Group IP multicast 224 1 1 1 JAA OISTIODUTON gt lt Hie atl Control Bana a Distribution Group IP multicast 239 255 255 255 The global data service currently implements GMPP to set up multicast filtering GMRP is the protocol that the end device uses to notify switches and routers that it wants to receive data from a particular multicast IP address That IP address b
359. munication redundancy inherent in it radio and satellite to overcome wiring restrictions telephone or Internet for remote point to point access at costs comparable to local calls e infrastructure components with low cost that are industrially hardened 31006929 8 2007 123 Planning and Layout Open System Interconnection Model OSI Model OSI and Automation The OSI model defines a seven layer model for data communications 7 Application Layer 6 Presentation Layer 5 Session Layer 4 Transport Layer 3 Network Layer 2 Data Link Layer 1 Physical Layer Layers 1 6 each provide a set of functions to the layer above it and layers 7 2 each rely on functions provided by the layer below it Messages can pass vertically through the stack from layer to layer Logically each layer can communicate directly with a peer layer on other nodes The following paragraphs focus on the layers and functions of the OSI model that apply to automation systems For a complete OSI description refer to OSI 7498 When the OSI model is applied to an automation environment standards are applied at each layer Each layer can perform its function for example the Modbus application layer transfers data around the plant without knowing anything about the layers below it You may adopt any suitable standard for each layer for example wireless or wired at the lower layers and FTP for file tra
360. munications manually For automatic management within the SCADA you need only to enable the service and configure the SCADA system to recognize that the two devices are the same If this support is not native to the SCADA you must perform additional configuration and programming to make the system communicate to the devices on both interfaces The most common problem is that the SCADA system is configured to communicate to the Ethernet interface of the end device not to the end device itself The SCADA system should view a Quantum PLC with two NOE modules e g IP address 192 168 1 10 and 192 168 1 11 as two separate devices even though the SCADA requests are exchanged with the same CPU The following illustration shows a SCADA system communicating to a PLC with two Ethernet interfaces The SCADA assumes that there are two PLCs and it must decide the one with which it will communicate 1 Data for both exchanges comes from the same variables in the PLC 2 The PLC has two interface modules 3 Two sets of data are exchanged The SCADA system needs to be able to retrieve the values it needs to display from one device or the other without affecting the final display of data If the path to one device is unavailable use the path to the alternate device or backup until the original path is available 31006929 8 2007 293 Services Overview SCADA Back up Watchdogs
361. n IP address the gateway IP address and the physical interface identification Each router knows only its local networks but passes this information on to other routers which builds up tables The router may be programmed to know just the first attached network or it may know several downstream If it does not know where to send a message it will pass the message to its own default router which is farther upstream in the network for processing Routing tables are created either by hand for a small system or automatically using routing protocols 31006929 8 2007 139 Planning and Layout Routing Protocols Path Cost Routing protocols decide on the contents of routing tables In a small stable system it is often best to program the routing tables by hand In a larger system or one that requires redundancy a routing protocol needs to be chosen Protocols used within a system include RIP a distance vector protocol that is the most widely used and OSPF a more recent link state routing protocol A distance vector protocol uses distance as measured in routing hops to determine a packet s optimal path Each node shares its routing table with the neighboring routers In a link state routing protocol every switching node router receives a full map of network connections passed from one node to another which it uses to calculate the best next hop from it to all possible destinations on the network RIP is robust its co
362. n IP datagram or packet An IP datagram is transmitted across TCP IP networks IP provides routing functions for distributing datagrams to the correct recipient for the protocol stack Other internetwork protocols include ICMP IGMP ARP and RARP These protocols do not replace IP but they can work alongside it The network interface layer is the interface to the actual hardware It is sometimes referred to as the link layer or the data link layer It supports packet oriented or stream oriented interfaces and does not guarantee reliable delivery TCP IP does not specify any particular protocol for this layer It can use almost any network interface making it a flexible network with backward compatibility for a legacy infrastructure IEEE 802 3 ATM and FDDI are examples of network interface protocols supported by TCP IP The ability to run the application layer and TCP IP over different physical layers allows the data SCADA traffic for example to run across a fiber link to remote sites and then across a star based copper link to the PLC or even a satellite link All this can be done without changing the application layer or the TCP and IP layers for addressing and data delivery 126 31006929 8 2007 Planning and Layout Transparent Ready Model Summary The following diagram shows how Transparent Ready implements the four layer TCP IP model see p 125 4 3 UDP TCP 2 IP 1 Ethernet
363. n describes the environmental requirements for an industrial Ethernet network Industrial refers to extreme environmental conditions mechanical climatic and ingress protection to which the devices are exposed and to noise immunity variables An industrial Ethernet must have predictable performance and a higher level of user friendliness under these extreme conditions What s in this This section contains the following topics Section Topic Page Environmental Standards Summary 68 Mechanical Requirements 69 Climate Protection Requirements 71 Ingress Protection Requirement 73 Electromagnetic Emission and Immunity Requirements 76 31006929 8 2007 67 Planning and Layout Environmental Standards Summary Standards for Environmental Variables Industrial and Telecommuni cations Standards Standards Compliance The value range for a system s environmental variables for example temperature as a climate variable is defined in industry standards set by UL CE IEC CSA CENELEC and others see p 69 Even though many standards are international and globally accepted efforts continue among the major standards organizations to reconcile existing standards and create new ones that agree with each other Standards often differ from region to region application to application and device to device Schneider Electric recommends that you take this into account when designing your Trans
364. n the case of a PLC or SCADA or by an internal timer for a SCADA or an HMI This allows you to initiate communications only when required and provides a more efficient use of resources If the data must be exchanged at a short fixed rate the I O scanner service see p 166 should be used instead if that service is supported by the client The Modbus server is accessed by either a Modbus client or an I O scanner service and should be used to transfer plant information commands or other required data The Modbus server provides real time data transfer or access to data reports that are stored in its memory The Modbus server answers any Modbus requests it receives No additional configuration is necessary Any device that needs to exchange plant status commands or data with other devices should implement a Modbus server A device that implements the server can respond to requests sent from Modbus clients and make its internal I O and data available to remote devices for reading and control The device may be an I O module a drive a power meter a circuit breaker a motor starter or a PLC I O modules are good examples of devices that implement a Modbus server service As servers input modules let other control devices read values from them and output modules let control devices write values to them A PLC system implements both client and server services The client service enables the PLC to communicate with other PLCs and I O mod
365. n the current type and are not common as yet The methodology used for setting up a firewall is important There are two ways to set up a firewall e allow all and then deny specific items e deny all and then allow specific items The method of deny allis the more secure because it restricts even those cases you had not thought of This is therefore the recommended setup method An access control list is implemented in layer 3 switches see p 60 and some layer 2 switches It provides a filtering service similar to a firewall but is based on a source destination port or VLAN see p 57 instead of an IP address It can be used at lower levels of a network on the plant floor to prevent access from one plant area to another Once an access control list is set up the system stops all types of access for example a person accidentally trying to connect to a PLC in the next area of the plant The setup method is the same as for a firewall 150 31006929 8 2007 Planning and Layout Port Security PLC Access Control Security Issues with Wireless Access Points The Schneider NxS272 device is able to protect each port using port security Port security functions similarly to an access control list but limits incoming connections based on a MAC address Settings can be made to control who has access every address or only a single address If an invalid address is detected settings can control the response no res
366. n two nodes in a network It can consist of a data communication circuit or a direct channel cable connection LLC logical link control or link layer control A data link protocol based HDLC developed for LANs by the IEEE 802 Committee and common to all LAN standards for data link transmission the upper part of ISO layer 2 LNI local network interconnect A port multiplier or concentrator that supports multiple active devices or communications controllers either stand alone or attached to standard Ethernet cable logical link A temporary connection between source and destination nodes or between two processes on the same node loss Also referred to as signal loss The attenuation or degradation of a signal during transmission LS low smoke A cable s ability to avoid giving off toxic smoke in case of fire M MAC media access control Generic term for the way in which workstations gain access MAC address MAN masquerading MAU MES to transmission media Most widely used in reference to LANs The media access control address of a device which is burned into a DNI card and is added near the beginning of the packet metropolitan area network A network that spans a geographical area greater than a local area network but less than a wide area network IEEE 802 6 specifies the protocols and cabling for a MAN However they could be superseded by ATM When a user appears to the system as another user Can be used for mal
367. n unshielded twisted pair cable 1OBASE T is a point to point network medium e g hub switch device to station 10 Mb s Ethernet running on thin coax network cable 10 Mb s Ethernet running on thick wire network cable IEEE specifications for local area networks LANs and metropolitan area networks MANs IEEE specifications for general management and internetwork operations such as bridging IEEE specifications that sets standards at the logical link control sub layer of the data link layer CSMA CD Ethernet standards that apply at the physical layer and the MAC sub layer IEEE specifications for token passing bus standards 31006929 8 2007 517 Glossary 802 5 IEEE specifications for token ring standards 802 6 IEEE specifications for metropolitan area network MAN standards IEEE 802 standards become ANSI standards and usually are accepted as international standards A ack number A sender transmits a message in this acknowlegement code to say that a message was received without errors ARP address resolution protocol A cache consisting of a table with matched hardware and IP addresses ATM asynchronous transfer mode A technology for high speed transfer of voice video and data over a network AUI attachment unit interface A 15 pin shielded twisted pair Ethernet cable used to auto negotiation auto sensing connect network devices and a medium attachment unit such as a transceiver The abi
368. nable patch cables Check device link lights if available Typically lights are green when operational amber during an error and unlit when no physical connection is detected by the hardware See the hardware user guide for details Check for duplex mode lights if available on device for speed settings 10 mb 100 mb auto etc Refer to Physical Layout chapter see p 27 Make sure that crossover cables have been used between network devices hub to hub switch to switch etc where required Check the device documentation for straight or crossover cable requirements Cable lengths should not exceed Ethernet specifications Test the backbone wire integrity with a testing device and re terminate wiring at the patch panel if suspect after completing logical checks NIC Make sure the traditional or PCMCIA network card is properly seated in the machine Swap the NIC card for another to test card performance network Check hardware e hubs switches routers and other network devices for power e port link lights for proper activity typically solid or blinking green e uplink cable connectivity for stacked devices For a suspect hub port or switch port substitute an identical port after you have completed logical checks 348 31006929 8 2007 Troubleshooting Problem Topic Cause and Actions Logical check OS At a DOS prompt type ping to check the basic level of network connectivity for replies
369. nable this mode to allow the computer to capture all data seen on the Ethernet cable connected to the computer For most tools you can set this as a general option within the tool for all captures or set it when the capture starts You need a special Ethernet card driver to enable this setting Most tools include Ethernet card drivers but all cards don t always function on all systems packets from the device being analyzed are not captured but broadcast packets are When a packet arrives at a switch the switch sends the packet out on only the port that is ultimately connected to the destination device As a result a packet capture tool connected to a spare port on the switch will not see the packet To allow the packet capture tool to see the packet do one of the following Replace the switch with a hub In this case you ll see traffic to and from all devices connected to the hub Insert a hub between the device in question and the switch The packet capture tool is then connected to the hub in which case you ll see only packets to and from the device in question Enable port mirroring This configures the switch to forward a copy of all packets sent or received on a port to a different port to which the packet capture tool is connected Port mirroring is not supported by all switches Configure the switch to operate as a hub Some switches support this feature as a disable learning option In this case the switch no longe
370. nd EN 50173 standards define the structure and configuration of cabling systems for office buildings and campuses They are almost identical in scope and content have the same terminology and provide the same technical information This generic cabling system is application independent and consists of an open system of cabling components that are easy to implement The cabling system described in the standard supports a range of services including voice data image and video This table summarizes updates to the ISO IEC 11801 standard Standard Description ISO IEC 11801 1995 Generic customer Based on the TIA EIA 568 cabling premises cabling standard defines a telecommunications cabling system for office buildings and campuses ISO IEC 11801 2000 Generic customer Released in 2000 updates earlier premises cabling standard based on new releases of 2nd Edition the TIA EIA 568 standard Administration documentation ISO IEC 14763 1 records Planning and Installation ISO IEC 14763 2 practices Testing of optical fibre cabling ISO IEC 14763 3 Testing of copper cabling IEC 61935 1 31006929 8 2007 483 Standards and Considerations This table summarizes the EN 50173 and related standards Information Technology Equipment European Standards Documents Reference Building Design Phase Application of Equipotential Bonding and Earthing in Buildings with EN 50310 Coding Design Phase
371. nd reflected back along the sides by the reflective material of the cladding A thick plastic jacket strengthened with special fibers surrounds and protects these two inner cores In certain types of cable the fiber can have a metal core that gives the cable additional strength Fiber optic cable has the ability to transmit signals over longer distances and at faster speeds than copper cable Also because fiber optic cable transmits light it does not present the problems of electromagnetic interference associated with copper cabling It is ideal for harsh industrial environments and outside connections between plants due to its high immunity to moisture as well as to lighting 82 31006929 8 2007 Planning and Layout Parts of a Fiber Cable Fiber Cable Types Introduction Typically a fiber optic cable consists of three parts e core thin glass center of the fiber that transmits light e cladding outer optical material that surrounds the core and reflects light back into the core e buffer jacket outer plastic jacket or coating that protects the fiber from damage and moisture Q 1 cladding 2 core 3 buffer coating A light signal can propagate through the core of a fiber along a single path called single mode fiber or multiple paths called multimode fiber Single mode fiber fie ee ea 04 WASH AN Jt AA IS AN Multimode fiber a ea 31006929 8 2007 83 Planning and Layout Fiber C
372. ndant System Basic Redundancy System Limitations The following questions must be answered to enable a communications based HSBY system to be implemented e What communication links must be monitored In the event of a failure should the links cause a changeover of the hot standby PLCs e What defines a communication failure time outs retries etc e Will redundant Ethernet interfaces be implemented If so how will they be addressed e How will the health of the communications network on the Standby PLC be monitored to be sure that a changeover improves communications To achieve basic communications redundancy for a minimum investment in extra hardware and time the system should have e a single network connection to each PLC in the hot standby system e network connections monitored using the module diagnostics functions Changeover can be set up to occur if the primary CPU cannot locate a SCADA platform or if the connection between the CPU and the Ethernet switch fails However hot standby PLCs cannot detect a communications failure due to a break in the network beyond their local connection 1 oon o SCADA monitoring a critical process controlled by the PLC Ethernet switch The primary CPU The standby CPU Racks of remote I O modules anon 31006929 8 2007 297 Services Overview The failure of a single critical device beyond the local connectio
373. nding of Equipment and Machines 98 EMC compatible Ethernet Wiring and Cable Runs 000 99 Ethernet Copper Cable Types 00 cece eect eee 105 Ethernet Copper Cable Tools 000 c cece 108 How to Make an Ethernet Cable 0 0c eee eee eee 109 Cabling Administration seii saci e eate ar cette 111 Cabling Documentation a na aaas cee 112 Verification of a Transparent Ready Industrial Ethernet 114 Transparent Ready Industrial Ethernet Verification Recommendations 115 Permanent LINKS i fadet te cc a p O46 Ged aaa PAR ea SAS 116 Channels iiae etek a eaa be denn Ged Gti dat kad 118 Testing a Copper Installation 2 2 0 0 0 eee 120 Additional Considerations for Designing a Transparent Ready Industrial Ethernet Network 0 0 0 0 cece et tees 121 Internet and IP Technologies in an Automation Environment 122 Open System Interconnection Model 0 00 c eee eee eee 124 The TGPAP Model sessed Sched baked Mente dank pane baw bees eles 125 Transparent Ready Model 0 cee eee eee 127 IP Addresses and Classes 0 0 0 cece eee teed 130 Multicasting Considerations 0 0 0 0 0 cece tees 135 Multicast Filtering e223 cee nade La ai a eta ee AE aA RS AS 136 Network Management 0 0 e cee eee tees 137 Routing dee hate heh cals yuna E AOE AIA btn as A a A RO ina ar aa DA Ancona 139 Introduction
374. nds the FactoryCast functions see p 237 by executing the following HMI Web features e real time HMI database management specific to the module and independent of the PLC processor e arithmetic and logical calculations for preprocessing data on the HMI e transmission of electronic messages triggered by a specific process event by email e connection to the SQL server and the MySQL and Oracle relational databases to archive tracking or logging data FactoryCast HMI is an active Web server that executes HMI functions integrated in a PLC module The active Web server eliminates the need for communication via polling to update the HMI SCADA database The FactoryCast HMI software configures the services on the module You need only to configure the parameters for each service no actual programming is required The software provides a simulation mode to test the application without a FactoryCast HMI module or a physical connection to a PLC thereby simplifying debugging Although other Ethernet devices with an embedded Web server can provide real time data they are unable to provide historical information or initiate Web services unless a client is connected The FactoryCast HMI devices have an integrated JVM A FactoryCast HMI device can provide historical trending information and initiate other Web services such as database logging and email The following illustration shows the FactoryCast HMI Web service data flow Thin client IP
375. necessary for the operating modes of OFS it is the only package able to run the server mode that is mandatory for the dynamic symbol update Unity Pro XL must be installed OFS launches Unity Pro XL and opens the application in background mode The SCADA OFS Unity Pro XL system runs on one PC Unity Pro runs on a separate PC for application modifications This PC does not need to be connected to the network permanently only for on line modifications When a PC server is used for the STU application files OFS and Unity Pro use the same application for the modifications and synchronization OFS accesses the data in the PLC in real time It detects any discrepancies between the running application and the local symbols file on the PC signature checking In accordance with the OFS QoS communication stops or switches to a bad quality service OFS Unity Pro XL updates the symbols by accessing the STU file Depending on the OFS settings this update can be automatic or triggered by the SCADA application by a specific command mode in OFS The application does not stop Only the OFS communication is interrupted during the symbol file update When Unity Pro handles on line modifications the STU application file handles the synchronization of OFS Unity Pro XL with the right version of the application Product Versions Product Version Comments Unity Pro M L XL v2 0 for the application modifications VijeoLook v2 6 includes the cor
376. need to physically read each meter saves a vast amount of time and resources 1 remote access to the power meters over the building s Ethernet network 2 office building configured for separate power metering for each tenant 31006929 8 2007 225 Services Overview Web Server Operation Summary When an HTTP client accesses the Web server the application receives the request and retrieves the required data from the device s memory The information is sent back to the client in the form of a Web page The Web server is a passive service it runs only when information is requested from it The Web pages are in HTML format they are stored on the Web server along with other data source files such PDF JPG etc Some Web servers can display real time data but a JVM must be installed to enable the client to display these Web pages When you try to access a Web page the Web browser issues a request to the server After the server handles the request it sends the HTML pages back to the client There are two types of Web pages e static pages which may or may not contain real time data If you want to refresh real time data the Web pages must be reloaded which means another request must be sent e dynamic pages which do contain real time data These Web pages contain Java applets that run on the client s JVM retrieve real time data from the Web server and display data in the Web browser
377. network that is considered sensitive so that it can be properly protected when transported over the Internet Remote Access Two general layouts of a remote access system are shown below one with a Server dedicated RAS server and one using a Windows server PC A 3 Ana ees o C3 eke ne 2 ena re GG Gaga Ga gage ae 4 Ke en ica oc 2 1 remote PC 2 modem 3 RAS server 4 modem 5 network RAS System e Anew global IP address is not needed The IP address of the PLC can be the Advantages one assigned on the company network e No ISP is needed There are no ongoing service costs for the company running the PLC e You can deliver a configured system anywhere in the world that becomes operational when a phone line is connected A modem compatible with the location must be installed prior to shipping 144 31006929 8 2007 Planning and Layout RAS System Disadvantages RAS System Components RAS Server Implementation A direct phone connection is required between the remote client and the RAS server Potential problems include cost poor quality phone connection slow speed A RAS server needs to be added to the Ethernet network that is connected to the PLC The default gateway of the PLC is set to the IP address of the RAS server A modem is added to the RAS server A good quality locally supplied modem should be adequate The RAS serve
378. new configuration For details see p 204 The time synchronization service provides distribution of a central time source to multiple devices on the network Accurate time in all devices allows you to properly synchronize events and manage the order of operations across a plant The time synchronization service should be used in any environment where timing plays an important role in operations It eliminates the need to manually set the time on each network device Also the accuracy can be as close as 1 ms in all devices a level of precision that cannot be achieved when you set the time manually For details see p 208 The electronic mail notification service allows service personnel to be notified of the plant status via email The email may include process data production reports alarms events and other information needed to evaluate plant status A device with the email service can automatically create short electronic mail messages that can use predefined recipients email addresses and message subjects The message body can be dynamically modified to include current plant data and other text The electronic mail notification service is used whenever email notification is a convenient communication option for informing someone of plant status operation reports or maintenance requirements In this case you are conveniently notified about maintenance eliminating the need of regularly checking the equipment to know when it
379. nfiguration is simple and its algorithm does not impose a burden on storage or computation capacity However it does not directly support subnetting requires a lot of bandwidth may be hard to debug may have problems making the many hops on a larger network and has weak security OSPF among its other advantages supports subnetting verifies a link by sending a small packet and can work with a larger network It does however use a lot of memory and computation capacity and is rather more complex When considering which protocol to use look at the ability to handle the number of routers in our system convergence time how long it takes to build the routing tables after a change and the amount of traffic generated by the protocol itself Path cost usually based on criteria such as hop count and media bandwidth is used to compare the cost of passing a packet over various paths on a network Path cost is defined for each network and is used by the routers to choose the optimal path to the final destination the lower the cost the better the path This is one way to prevent the data from being sent around and around the router network 140 31006929 8 2007 Planning and Layout Introduction to Remote Access Summary Examples Methods In a plant environment access to the industrial control system is essential for capturing data troubleshooting control and minor adjustments With critical applications and indus
380. ng and Layout 2 4 Selection of Industrial Ethernet Components At a Glance Overview This section provides information about the proper selection of industrial Ethernet components It discusses recommended connectors for office or light industrial use and for heavy industrial use Copper cables for an industrial Ethernet network and the tooling needed to manufacture the cables are also discussed What s in this This section contains the following topics Section Topic Page Ethernet Copper Cables 78 Fiber Optic Cabling 82 10 100BaseF Physical Layer Specification 86 Ethernet Connectors for Copper Networks 87 Fiber Optic Connectors 90 Recommended Infrastructure Devices for Industrial Ethernet 92 31006929 8 2007 77 Planning and Layout Ethernet Copper Cables Introduction Twisted Pair Cables Classification and Cable Categories Ethernet cables route transmitted signals from one device to another When you make cables you need to know what types of devices you will be connecting Most Ethernet systems use routers switches and hubs to manage information flow These devices require a different type of cable than the type installed between two end devices that communicate with each other directly Transparent Ready s industrial Ethernet must use shielded CAT 5E twisted pair cables or better Twisted pair cabling is a common form of wiring in which two conductors are w
381. ng infrastructure administration standard Defines design guidelines for managing a telecommunications infrastructure TIA EIA 607 1995 Grounding and bonding requirements Defines grounding and equipotential bonding requirements for telecommunications cabling and equipment ANSI EIA TIA 570 A Residential telecommunications cabling standard 482 31006929 8 2007 Standards and Considerations ISO IEC IS 11801 and EN 50173 Standards The TIA EIA standards define a structured cabling system that is designed and built in multiple blocks The blocks are integrated into a hierarchical network to create a unified communication system LANs represent blocks with lower performance requirements while backbone network blocks which require high performance fiber optic cable perform the work of connecting the blocks to each other in a star topology The standard also specifies the requirements for fiber optic single and multimode STP and UTP cable In general the TIA EIA 568 wiring standard provides e specifications for a generic telecommunications wiring system for commercial buildings e specifications for media network topology termination and connection grounding points and administration of wiring systems e support for environments that use several different products and vendors e information about planning and installing a telecommunications network for buildings The ISO IEC 11081 a
382. ng the application protocol The gateway waits for a response then passes this response back to the source network This type of gateway is the most efficient and powerful implementation because no limits are put on the protocol However this gateway is possible only if both the source and destination networks use the same application layer protocol Schneider s Modbus Ethernet to Modbus serial and Modbus Ethernet to Modbus Plus gateways are examples of this gateway type Note A minor modification of the application message is made in conversion from Modbus Ethernet to Modbus Plus or Modbus serial a bridge index and transaction ID are included in a Modbus Ethernet packet but these are not present at the applications layer for Modbus Plus or Modbus serial On Modbus Plus the bridge index is part of the addressing used by the lower layers On Modbus serial the index is not required A transaction ID is not required on either system This type of gateway receives the packet containing the application layer message and removes the lower layers before passing the message to the destination network Because the actual message is not interpreted the total system response time can be lower and you can use functions supported by both networks Gateway Network A Network B Application Presentation Session Transport Network Data Link x x x x x x Physical
383. ngs e network hardware functionality changes multicast filtering default gateway routing configuration Traffic A high volume of network traffic can cause problems that are difficult to isolate and Congestion solve Software utilities such as network sniffers and protocol analyzers help you troubleshoot congestion issues In most cases you should be trained for these specific tools Unfortunately the tools often indicate only general problems like broadcast errors In large switched networks it is more difficult to isolate and analyze congestion without the aid of hardware probes and vendor specific software tools A quick understanding of the magnitude and scale of an issue can guide your attempts to find and fix the problem quickly and efficiently If the issue creates non critical problems for only a few users you might choose a troubleshooting method that does not require a complete network outage In a case of widespread communications problems you may need to physically segment the network to help you quickly isolate the problem 31006929 8 2007 347 Troubleshooting Connection Troubleshooting Problem Topic Cause and Actions Physical cables see Use the proper physical cable connections from the end device to the wall patch check note panel hub or switch Also check for cable defects lacerations and causes of interference like electrical noise Replace questio
384. nning and Layout Cable Run Recommen dations N unshielded cables shielded cables Establish continuity of the earth plane between two cabinets machines or pieces of equipment Place all conductors against the earth plane end to end panel at bottom of cabinet exposed conductive parts of metal enclosures equipotential structures of machine or building accompanying conductors cable troughs etc Follow the shielding rules described in this chapter en kOND Use metal cable troughs Correctly connected they provide very effective cable shielding The shielding protective or screening effects of a metal cable trough depend on the position of the cable Install Ethernet cables in the corners of a cable duct as shown in the diagram below gt open cable trough area exposed to EMI disturbances corner angle area specially protected against EMI disturbances 31006929 8 2007 101 Planning and Layout e f for special reasons Ethernet cable must be installed in the same trough as type 3 and 4 cables leave the cable trough open This type of installation is not recommended e Whenever possible use two metal ducts one for interfering signals power relays and varistors and the other for signal cables sensors data telecoms These two ducts can be in contact if they are shorter than 30 m From 30 to 100 m space them 10 cm apart either side by side or one above the other e Atall t
385. ns There are two stages of communications in the SCADA to device path in the SCADA e between the display client and the I O server System e between the I O server and the PLC or standalone system You may use multiple I O servers to enable redundancy 276 31006929 8 2007 Services Overview I O Server to Field Device Communications Summary Exception Reporting Exception Reporting Problems The way a SCADA system gathers data from the field device can greatly affect network and device loads and overall system response times Communications between the I O server and the field devices can follow several common models Most SCADA systems use a combination of e data exception reports from field devices e O server polling for field status based on user configured groups and time periods e O server exception writes in response to operator commands e O server time based read writes for tags used in application code Exception reporting is the most efficient but least common method for transferring data between a field device and the SCADA system The field device needs to be aware of the tags the SCADA system is using and needs to monitor these tags for changes in the field device When a value in a tag changes the field device writes the new value to the SCADA For this method to work the field devices needs to be able to initiate communications with the SCADA system through a Modbus messaging client and
386. ns can cause the failure of the entire communications system as shown in the illustration above Fully Redundant A fully redundant system must be implemented when the specification calls for no System single point of failure for the control system including communications 1 Redundant SCADA system with dual linked Ethernet interfaces 2 Switch based network with spanning tree 3 ConneXium redundant ring network 4 Hot standby PLC system with dual independent Ethernet interfaces A fully redundant system typically uses the following additional network hardware installed for redundant network paths each PLC in the hot standby system connected to a separate network path each PLC connected to the network at multiple points using multiple network cards in the PLC for a network or network card failure that does not trigger a changeover e communications paths monitored by watchdogs for communications integrity along the entire path to the end devices e other devices such as the SCADA system connected to the network at multiple points using multiple network cards e optionally a complete second physical network e each connection point switch or a hub for a device e g PLC SCADA system etc powered from a separate power supply so that the failure of a single power supply does not disconnect the device from the network 298 31006929 8 2007 Services Overview Fully Redundant System Limitations
387. ns module The CPU logic scan times vary Modbus client response times are tracked with respect to six Modbus server response times lt 1ms 10 ms 20 ms 50 ms 70 ms o e 100 ms 31006929 8 2007 435 Modbus Client Performance At a CPU Scan Time of 200 ms CPU Cycles oO AM ONO O 10 Communications Completed 15 20 The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 200 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 1 1 1 1 OINI OJOJ RAJON 11 12 13 14 15 16 17 NINININI NIN AJAI AR PRL WOW WwW wow OINININI NIN Oran a a AIAI BRL BR WwW Wl w rm ni ry DOIPNINI OO a ala AIAJ WwW OI ny rm 436 31006929 8 2007 Modbus Client Performance At a CPU Scan Time of 100 ms 16 14 10 CPU Cycles O 5 10 15 20 Communications Completed The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 100 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 1 1 1 1 1 1 2 1 1 1 1 1 2 3 1 1 1 2 2 3
388. nsfer or Modbus for data transfer at the higher layers All this can be put in place without modifications to any other layer Ethernet is a standard physical and data transport system common to all automation vendors Application protocols can vary to suit the environment some are standard others are specific For example FTP and HTTP are standard and common to all vendors while Modbus and others are vendor specific Some protocols Modbus for instance are open standards others are available from only a single vendor 124 31006929 8 2007 Planning and Layout The TCP IP Model Summary The TCP IP model was developed at the same time as the OSI model see p 124 and has become the protocol of choice for most data communication networks TCP IP consists of a four layer protocol stack that is a compressed version of the OSI model 4 Application Layer 3 Transport Layer 2 Internetwork Layer 1 Network Interface Layer This protocol stack has no specific mapping to layers 5 and 6 of the OSI model Application The application layer runs the actual application and protocol Common applications Layer include Modbus Ethernet IP Profinet Telnet FTP SMTP and Gopher Interfaces between the application and transport layers are defined by port numbers and sockets TCP IP can run different application layers simultaneously allowing an automation network to carry SCADA see p 274 traffic v
389. nt documentation The FactoryCast HMI Web incorporates an active Web server in the device provides better Web pages supports more clients and allows database connectivity For details see p 230 160 31006929 8 2007 Services Overview Transparent Ready Support Services and Protocols SNMP FTP TFTP Telnet The SNMP service is for managing networks It is a network management system that uses SNMP compliant devices that are queried for information about themselves and the network SNMP is in almost every Ethernet device and should be used as the basis for most network management systems It can be used to discover monitor and configure devices on a network SNMP is normally used to transfer device and network status not plant status For details see p 244 FTP is a method for exchanging files between devices over a network Almost all operating systems today include an FTP client or server functionality making file transfers from one device to the next an easy task Many network devices implement FTP as a standard method for transferring information to update its internal software or firmware For details see p 243 TFTP is a simpler file transfer protocol than FTP typically used for small file transfers and by less complex devices For details see p 246 The Telnet protocol provides an interactive client host type communication session where you can type commands to view or manipulat
390. nt for use in telecommunications environments It has been standardized in the EIA TIA 604 10 standard Small form factor SFF connectors like the MT connector are a more recent addition to the class of optical connectors The MT Mass Termination connector refers to the 12 or 24 fibers that it connects The name of its duplex cousin the MT Ru refers to the RJ 45 style of copper connector it resembles 90 31006929 8 2007 Planning and Layout Fiber Optic Connectors Schneider Electric recommends the use of the following connectors for the Transparent Ready Industrial Ethernet Environment Physical Recommended Appearance Layer Connector Light 10Base FL ST industrial and heavy industrial environment 100Base FX SC 100Base FX MT RJ 31006929 8 2007 91 Planning and Layout Recommended Infrastructure Devices for Industrial Ethernet Recommen dations Schneider Electric Recommendations for Use of Industrial Ethernet Infrastructure Devices General Use switches as much as possible to eliminate collisions increase performance and simplify network design Avoid using hubs whenever possible Understand network traffic and segment network properly Follow environmental recommendations provided in this manual When high bandwidth availability is required Use full duplex switches 10Base T 100Base TX Understand network traffic
391. nt ring uses logical management on the switch to reroute traffic across a single link structure Self Healing When a link on the redundant ring fails a standby link is activated within a fraction Operation of second Through the use of a redundancy manager the switch monitors the ring using watch dog packets If one link in the ring fails the redundant connection performs self healing by activating the redundant link to take over data packet transmission Once the broken link is resolved the self healing link is re activated LI O U7 r Process control Production line 1 Production line 2 Production line 3 Redundancy connection Redundancy manager active on switch Watch dog packets NO oO BROD 31006929 8 2007 53 Planning and Layout A OOODAUANOON NAMNI F sceccemcase Process control Production line 1 Production line 2 Production line 3 Network fault Redundancy connection takes over data packet transmission Redundancy manager active on switch Data packet able to reach all nodes ONO hWD Advantages Disadvantages Less complex requiring only a single physical connection More cost effective a single interface and network are used Automatic self healing that detects faults and reroutes data packets If two links fail simultaneously connectivity co
392. ntact your company s IT department 31006929 8 2007 243 Services Overview SNMP Service Summary With the SNMP service you can monitor the status of the network and the devices connected to it This service supports the management of many diverse network devices using a single system It consists of the network management system the SNMP protocol and the SNMP agent in each network device g O 5 COT SNMP agents The SNMP protocol is used to exchange network management information between the network manager or management system such as HP Openview IBM Netview etc and the SNMP agents 244 31006929 8 2007 Services Overview SNMP Service Operation SNMP Security The information available in a device is listed in a data structure called a management information base MIB A MIB contains data definitions of the attributes for each of the network managed objects so that the management system can gather and combine information from multiple devices The SNMP service monitors the state of the network modifies device configurations and generates alarms based on device failures Many standard MIBs have been developed MIB II Switch MIB etc Devices implement these MIBs to provide standard information to any network management system Depending on t
393. number of bits per Modbus message For the actual network transmission time use the number of bits in the message 8 x 1 baud rate For a Modbus read request at 9600 baud the time is about 5 ms A response is about 100 ms for 100 registers of data The system response time is determined by the number of requests sent through the bridge the more requests sent the slower the overall response time for all devices To determine the number of devices on a system first determine the total number of Modbus requests to gather all the data The best response time the system can give is number of requests x time to transmit the request on the serial line response time of the serial device time to transmit the response on the serial line 50 ms The average response time for a serial device is 200 ms but may vary from 50 to 500 ms The time to transmit the request response depends on the speed of the network and the Modbus RTU ASCII setting e RTU is much faster because fewer bytes are transferred e An average Modbus read request at 9600 baud is 5 ms e Amaximum response is 100 ms The total best case system response would therefore be 5 ms request 200 ms serial device response 100 ms response 50 ms 350 ms request For 8 Modbus devices with 2 requests each the best case response time to get data from the system is 16 x 350 ms 5 6 s 338 31006929 8 2007 Services Overview Calculation of t
394. ociated with a new internal variable A user defined trigger initiates the processing of each spreadsheet 240 31006929 8 2007 Services Overview Devices that Support The FactoryCast HMI Web Service Device Quantum 140NWM10000 Premium TSXWMY100 31006929 8 2007 241 Services Overview 3 11 Other Services At a Glance Overview This section describes other support services available with some Transparent Ready devices These services are implementations of standard IT infrastructure services that may be used for system maintenance and monitoring What s in this This section contains the following topics Section Topic Page FTP Service 243 SNMP Service 244 TFTP Service 246 Telnet Service 247 Quantum Device Support for Other Services 249 Other Services Supported by Premium Devices 251 Other Services Supported by TSX Micro Devices 253 Other Services Supported by Momentum Devices 253 Other Services Supported by Advantys STB Devices 254 Other Services Supported by Power Logic Gateways Bridges 254 Other Services Supported by ConneXium Cabling Systems 255 242 31006929 8 2007 Services Overview FTP Service FTP Service Summary FTP Security FTP is a client server protocol used by many systems to transfer files between devices Many devices including Transparent Ready devices implement FTP to transfer informat
395. ocol The following table shows that the clock synchronization resolution differs depending upon which CPU you use with these two Ethernet modules Unity Module and Processor Used Predicted Typical Time Service Operation Ethernet Modules Ethernet Modules with Unity Processor Clock Synchronization Event Synchronization Time Stamping TSXETY5103 TSXP570244M 1 ms typical TSXP571x4M 10 ms maximum TSXP572x4M TSXP573x4M TSXP574x4M 1 ms typical TSXP575x4M 5 ms maximum 140NOE 77111 140CPU31110 1 ms typical 140CPU43412U 10 ms maximum 140CPU53414U 140CPU65150 1 ms typical 140CPU65160 5 ms maximum 140CPU67160 clock synchronization precision ae fast task time I O time clock synchronization precision I O time 1 Time difference between field input and central server 2 Assuming input connected to the interrupt module TSXETY5103 modules must be v3 1 or greater and they are compatible with Unity 2 0 or greater 140NOE77111 modules must be v3 5 or greater and they are compatible with Unity 2 0 or greater 216 31006929 8 2007 Services Overview 3 7 Electronic Mail Notification Service At a Glance Overview This section describes the electronic mail notification service and how it provides users with process data production reports alarms and event notifications What s in this This sec
396. odel uses the same computer or terminal to poll and display data from devices in the field Each additional display terminal polls its own data from the field devices This illustration shows an HMI and a PC with SCADA polling a PLC for data HMI polling SCADA polling 31006929 8 2007 275 Services Overview Client Server The client server model uses a separate I O server and display clients The I O Model server polls data from the field devices and the clients display the data Each client obtains the data from the I O server not the field devices The I O server combines all the requests from the display devices and gathers the required data from the field devices to the SCADA system As a result the load on the network and the field devices is lower and the system response time improves In some systems the I O server can be the same physical device as the display device Note Multiple I O servers can be used to enable redundancy This illustration shows that the requests from the SCADA client are being obtained from the PLCs by the I O server SCADA clients PLCs A SCADA system may include other servers such as trending alarms etc These servers are not included in the description here because they use the I O server to communicate with the field devices The data used by the SCADA system are called tags Tags can be used for display trending alarming reporting etc Communicatio
397. of the cable The use of shielded cable without earthing connections is not recommended Without a n earthing connection the shielding is ineffective against magnetic fields and both HF and LF disturbances Any possible contact with the cable shield creates a potential safety issue because of the potential difference between the shielding and the ground 31006929 8 2007 507 Earthing Grounding Procedures Advantages and Disadvantages connection choice for your installation The following table describes the advantages and risks associated with these two earthing methods Use this information to help you decide what is the best earthing Ground Connection Method Advantages Restrictions Earthing connection on both ends of the cable Extremely effective against external LF and HF disturbances Very good shielding effectiveness against resonance frequency on the cable No potential difference between cable and ground Enables common laying of cables that feed different class signals Very good suppression of HF disturbances Ground fault current can be induced in high frequency signals with high interference field strength for long cables gt 50 m Earthing connection on only one end of the cable Average shielding effectiveness Ineffective against external disturbances caused by high frequency electric fields Enables protection of isolated lines against low frequency
398. ogram that filters the information coming through a connection into your network A firewall inspects each packet and decides if that packet will be allowed to pass based on e source IP address e destination IP address e destination TCP port number which protocol is being used Place firewalls ar critical junctions within your networks such as e between the office network and the plant floor e between areas of your plant e between contractor laptops and the plant By filtering with basic firewalls you can limit access to a certain area of your network or to acertain device based on the information coming from the computer attempting access Since the access is IP based you cannot filter per person You can allow access to a device but restrict the protocols that can be used For example you can allow web page viewing but not FTP for firmware transfer With Modbus filtering however you cannot allow data monitoring without allowing programming as well since these are both in one protocol One possible solution is to allow only several OPC services to perform data access and to block all other devices This also prevents monitoring with a programming package More advanced firewalls are appearing that can inspect the upper layers of Ethernet packets and determine if they can pass This allows application layer filtering but also means that these firewalls do not allow Modbus programming commands These firewalls are slower tha
399. ol circuits with inductive loads and suitable Interfering cables protection Clean AC power supplies Main power supplies connected to power devices 4 Interfering Signal disturbs other class Welding machines signals Power circuits Electronic speed controllers Switching power supplies Data transmission such as that on an Ethernet network is a class 2 signal 31006929 8 2007 99 Planning and Layout General Wiring Recommen dations Equipotentially bond the site and the cabinets Position possible sources of interference away from sensitive equipment Do not combine Ethernet signals with class 3 or 4 signals in the same cable or conductor bundle Always try to maximize the distance between the Ethernet cable and cables carrying signals of different classes especially interfering signals 3 4 The longer the cable run the greater the clearance required between cables To take advantage of the HF protection effects flatten any connection against equipotentially exposed conducting structures For internal connections to cabinets and machines systematically flatten the cables against the metal supports Make sure Ethernet cables cross any cables carrying interfering signals 3 4 at a right angle as shown in the diagram below e f you need to collocate cables carrying signals of different classes in a single cable trough use shielded cables as shown in the diagram below 100 31006929 8 2007 Pla
400. om the field devices in supervision pages A basic HMI application must notify maintenance personnel of an event and let them view the status of a field device The Transparent Ready services used are e email notification e data display and transmission commands via Web pages The standard network management protocol SNMP can be used from a network management station to monitor control and perform diagnostics on all components in the Ethernet architecture see p 244 156 31006929 8 2007 Services Overview Inter PLC Level Data Transfer When data is sent in point to point mode according to PLC programming algorithms Communication and the required response times are in the 200 ms to 1 s range the main Transparent Ready service to be used is Modbus TCP IP messaging see p 179 Synchronizing Broadcast communication uses real time exchanges to synchronize several Applications applications Data is exchanged in low volumes Response times in the10 to 500 ms range are required The Transparent Ready Global Data service see p 197 is particularly suitable for synchronized data exchanges Field Level Communications Field PCs and Field level communication is used to configure monitor and maintain field devices Operator for diagnostics and monitoring Communication procedures must be simple so that Terminal less qualified personnel can access first level diagnostics from a standard PC Communication The
401. ommon Problem Hunting In a Quantum hot standby system the IP address of the Ethernet modules in the standby rack is automatically set to the IP address of the Ethernet module in the primary rack plus one For example if the NOE module in primary rack is address 192 168 1 10 then the NOE in the standby rack is 192 168 1 11 When the system performs a changeover the IP addresses of the Ethernet modules also swap This simplifies communication programming for other devices since they can always communicate to a single IP address This feature is available with the exec version 2 0 or greater of the NOE 77100 10 modules The PLC code in a Quantum PLC can initiate a hot standby system changeover with the Hot Standby control word To cause a change from primary to standby the primary PLC sets the bit to indicate that it is offline After changeover the new primary PLC can be used to set the original PLC back online Since there is already a primary PLC running in the system the original primary PLC comes back on line as the standby PLC Note Manually setting the primary PLC offline to force a changeover works only if the standby unit is available and able to go online Make sure the PLC code checks this using the hot standby status word before a change is initiated by the PLC code Failure to do so may result in both PLCs going offline Hunting is the term used for a problem in a hot standby system implemented with multiple c
402. ommunications paths It describes a situation where one device e g the SCADA system is attempting to communicate using one communications link e g to the Standby PLC to determine if that link is the correct one The primary PLC waits for a good SCADA system communications watchdog Since neither system is able to receive a valid communications watchdog each attempts a new path If both systems swap at the same time they only continue to swap and never establish communications on the same link To avoid hunting e monitor all the active communications links for watchdogs including the links in the Standby PLC e establish a clear system master such as the primary PLC If the primary PLC sees communications to the SCADA system on both primary PLC links and standby PLC links it does not change over It waits for the SCADA system to establish communications on the correct link in this case a link to the primary PLC e set different amounts of time for the SCADA system and the PLC to try a communications link If the PLC is the system master it should wait and monitor its current link for the amount of time required for the SCADA system to attempt communications on all the possible links Only after this time should the PLC switch to another communications link 31006929 8 2007 301 Services Overview Hot Standby Swap and Ethernet Services Services Available Services not Available Changeover Operation The
403. omponents use monitoring software and device based LEDs to indicate failures most single points of failures can be diagnosed and repaired quickly Resilience a cable failure takes only that device out of service You can have more devices on a single network than on a bus topology Star topologies are more costly because a dedicated cable must be run to each device To offset this disadvantage network infrastructure components switches hubs etc are used in cabinets on the factory floor so that a group of local devices can be connected together A single long cable can be run back to a central point to support the group rather than using separate cables for each device In daisy chain topology the device is part of the trunk cable unlike in bus topology where the device is connected to the cable through a tap connector and is not considered part of the trunk cable Every device in a daisy chain has two network ports information flows through the device Although a daisy chain is linear there are branching devices available that allow the development of more complex topologies The Interbus is an example of as daisy chain network Advantages Disadvantages Low cost there is no In a linear configuration if a device fails the network gets cut need to consider Tap connectors If not properly designed the devices in a daisy chain may become overloaded trying to manage the informa
404. on Fault Conditions Condition Cause Response A device is not found on the network The I O scanner device issuing the ARP requests attempts to locate the remote device Requests are sent every 30 s Socket overload a remote device refuses to accept a TCP socket connection This error is commonly seen on bridges with many entries in the I O scanner or in low end devices that support a limited number of sockets It occurs as an I O scanner health bit goes off at random intervals If the remote device is unable to open the TCP socket the I O scanner device attempts to open a socket every second If the problem persists you may be able to correct it by using the enable disable feature see p 172 To free up sockets limit the number of I O scanner data exchanges operating to the same IP address A remote device refuses FC23 If you are using pre Unity 2 0 I O scanner systems or end devices that do not send back the correct error code the I O scanner fails It continues to send FC23 and continues to fail When this failure occurs the device sends back a Modbus exception with an error code corresponding to function code not supported The I O scanner falls back to a combination of FC3 andFC16 A request or response packet is lost or the socket is corrupted and unable to transfer data Normal TCP socket transmissions occur on the first retransmission by the I O scanner device a
405. onals initially viewed Ethernet as a nondeterministic Suite of approach to a set of applications that depended heavily on real time solutions Most Protocols suppliers preferred to focus on other technologies mostly proprietary What finally brought Ethernet acceptance in the industrial world is a combination of features called the Internet suite of protocols This suite known as TCP IP was introduced to the market in 1983 as a reliable and simple way to communicate from multiple sites with different network types TCP IP is independent of the underlying network technology It can run on top of Ethernet IEEE 802 3 token ring PPP ATM DSL or several other technologies The suite comprises many protocols the best known of which are TCP and IP Other parts of the suite include the ARP and RARP data link layer protocols transport protocols such as UDP management and information protocols such as SNMP DNS BootP and NTP routing protocols such as EGP application protocols such as FTP TFTP Telnet SMTP and NFS These protocols each provide different functions and are located on different layers in the model 128 31006929 8 2007 Planning and Layout Model Support for Transparent Ready Services The Transparent Ready model supports universal Ethernet services such as HTTP BootP DHCP and FTP The model also supports these Transparent Ready specific services I O scanning global data Modbus TCP messaging faulty
406. ons and power limited circuit cable Level Il performance requirements are similar to those for Type 3 cable multi pair communications cable of the IBM Cabling System Technical Interface Specification GA27 3773 1 These requirements apply to both shielded cable with two to 25 pair conductors Level Ill data cable complies with the transmission requirements in the EIA TIA Wiring Standard for Horizontal Unshielded Twisted Pair UTP Cable and with the requirements for Category 3 in the proposed EIA TIA 568A Standard These requirements apply to both shielded and unshielded cables Level IV cable complies with the requirements in the proposed National Electrical Manufacturer s Association NEMA Standard for Low Loss Premises Telecommu nications Cable Level IV requirements are similar to Category 4 requirements of the proposed EIA TIA 568A Standard These requirements apply to both shielded and unshielded cable constructions Level V cable complies with the requirements in the proposed NEMA Standard for Low Loss Extended Frequency Premises Telecommunications Cable Level V requirements are similar to Category 5 requirements of the EIA TIA 568A Standard These requirements apply to both shielded and unshielded cable constructions unified messaging application protocol Brings together all messaging media in a single interface Uni TE An application layer communication protocol This service enables read and write access to variable
407. ontains the following topics Section Topic Page Introduction to Network Troubleshooting 346 Connection Troubleshooting 348 Intermittent Connection Troubleshooting 350 Slow Connection Troubleshooting 351 Remote Access Troubleshooting 352 31006929 8 2007 345 Troubleshooting Introduction to Network Troubleshooting Problem Types The most common network problems on Transparent Ready systems are e physical e logical e traffic congestion The intelligent switches and high speed network interface cards in modern networks create complex network configurations and operations In such an environment problems can be hard to isolate Intermittent problems are the hardest to troubleshoot It is a lot easier to tell when you ve solved a constant problem than one that comes and goes The ability to troubleshoot a problem is often a function of the investigator s comprehension of the physical and logical network design The quality of on hand documentation can also be a factor Physical Physical connection problems are generally the easiest of the three common types Connections to troubleshoot Making sure the network cable is plugged in is only the beginning of the investigation of the network s physical connectivity Cable testers and hardware performance indicators often just lights on network devices help you identify and isolate physical connection issues More complex physical connection problems can be r
408. ooting 360 SMTP Troubleshooting 361 Time Synchronization NTP Troubleshooting Table 362 Web Troubleshooting Table 363 354 31006929 8 2007 Troubleshooting Services Troubleshooting Problem Topic Cause and actions category Service all services failed You can ping a network device but no other device failed services function see p 345 Modbus messaging Modbus messaging does not function For example communications from PLC to remote devices communications from most SCADA systems to a PLC or device I O scanner I O scanner service fails as indicated by error bits that are on in the I O scanner service network management SNMP A network management system is unable to read or write values to the end device For example a network management system can discover a device but can not read information about the device global data The global data service fails as indicated by health bits that are off in the global data service Telnet FTP Telnet is unable to connect to the device for example you can not configure a bridge device with Telnet FTP is unable to connect or transfer files to the device for example you can not download Web pages with an FTP client faulty device replacement BootP A device is unable to obtain an appropriate IP address or parameters through BootP or FDR indicated when the device continually issues BootP requests The LEDs indicate this err
409. oposed and or required for testing and their associated standards The most important standards for industrial Ethernet Related networks are in the last two columns Standards Standard ISO IEC 11801 TIA EIA 568B ISO IEC 11801 Addendum to TIA 2000 2000 EIA 568 B Status Approved Approved Draft Draft Class or Category Cl C 16 MHz CAT 3 16 MHz Cl C 16 MHz CAT 3 16 MHz frequency range Cl D 100 MHz CAT 5e 100 MHz Cl D 100 MHz CAT 5e 100 MHz Cl E 250 MHz CAT 6 250 MHz Cl F 600 MHz Wire Map x x x x Length x x Propagation delay x x x x Delay skew x x x x Insertion loss attenuation x x x x PP NEXT loss x x x x PS NEXT loss x x x x PP ACR x PS ACR x PP ELFEXT x x x x PS ELFEXT x x x x Return Loss x x x x DC resistance x x 510 31006929 8 2007 Earthing Grounding Procedures List of Parameters The following parameters are required in the testing and performance measuring of balanced cabling permanent links and channels nominal impedance see p 512 return loss see p 512 attenuation see p 512 pair to pair NEXT loss see p 513 power sum NEXT see p 514 pair to pair ACR see p 514 power sum ACR see p 514 pair to pair ELFEXT see p 574 power sum ELFEXT see p 514 DC loop resistance see p 515 propagation delay see p 515 delay scew see p 515 longitudinal to differential conversion loss see p
410. opper Installation 120 114 31006929 8 2007 Planning and Layout Transparent Ready Industrial Ethernet Verification Recommendations Introduction Schneider Electric recommends that you follow the requirements for industrial Ethernet networks described previously in this chapter A certified Transparent Ready industrial Ethernet network must comply with the following requirements Transparent Ready Industrial Ethernet Requirements 1 Installation Correct installation as set forth by ISO IEC 11801 Correct installation Requirements as instructed in this guide Correct installation as required by the application for example wiring of a device or machine according to the specifications supplied by the manufacturer 2 Performance Performance criteria as set forth by ISO IEC 11801 Requirements 3 Environmental Environmental protection as described in this guide Requirements The following discussion provides information about how to test a network and verify its conformance with requirements for items 1 and 2 in the table above Additional In addition to the requirements presented in the ISO IEC 11801 Schneider Electric Recommen recommends that you dations 1 Select the right components as defined in this guide so that the network conforms to the performance and environmental requirements of a properly installed industrial Ethernet Read this guide carefully before you
411. or At the DOS prompt use the ipconfig command to see if a device receives an IP address and associated IP parameters Check the operating system network configuration For example e ls the hardware card operational e Are the TCP IP protocols properly bound to NIC Check the IP address configuration e For static addressing is the IP address and subnet mask typed correctly e f required is the default gateway address correct for source and end devices 352 31006929 8 2007 Troubleshooting Problem category Topic Cause and actions If you encounter trouble while connecting to remote networks type trace route at the DOS prompt to check network routing hops for failing points If you discover a timeout at a router hop discuss and validate the problem with the person who is responsible for that router application For specific VPN client software make sure you have basic Internet access before you establish the VPN tunnel Configure the VPN with appropriate authentication options See the local IT network administrator Make sure that optional firewall software that runs on end devices does not filter connectivity for specific applications or protocols network hardware Check the remote access server or VPN configuration and VPN logs for e event information connection attempt If the network uses an independent authentication server make sure the end
412. or Otherwise the device goes to the default IP address Web You can not access Web pages or some Web page functions do not work correctly For example you can see Web pages but live data from a device is replaced with an error message or blank space NTP time stamping A device is unable to obtain the time from the NTP server or the time is not accurate SMTP e mail A device is unable to send an e mail message 31006929 8 2007 355 Troubleshooting Modbus Messaging and I O Scanner Troubleshooting General Errors Topic Problem Solution is too slow no Service response error generated This is usually caused by e overloaded client or server see p 331 causes slow response e TCP socket problem or packet loss see p 367 Timeout error data is not transferred The error response from the client identifies timeout errors usually caused by e slow response from the server see p 327 e a lost packet on the network see p 367 e socket error see p 321 data is not transferred TCP socket error Solve this problem by correcting the TCP socket error which can be alost packet on the network see p 367 asequence or ack number problem that is caused by a problem with the TCP implementation of either end device see p 367 This is an error on the TCP socket that carries the Modbus message In this case the TCP socket
413. or timeouts At DOS prompt type ipconfig to see if the device receives an IP address and associated IP Check the operating system network configuration For example e Is the hardware card operational e Are the TCP IP protocols properly bound to NIC Check the IP address configuration e For static addressing is the IP address and subnet mask typed correctly e Is the default gateway address if required correct for source and end devices If you encounter trouble while connecting to remote networks type trace route at a DOS prompt to check network routing hops for failing points If you discover a timeout at a router hop discuss and validate the problem with the person that is responsible for that router For wireless connections check the validity of these configuration settings e SSID e channel e type a b g encryption key NIC Check the duplex speed settings autonegotiate 10 mb 100 mb etc If possible match the duplex settings on the end device with that of its network port Make sure the network interface drivers and adapter settings have been properly installed on the end device Update or reload the NIC software drivers from the manufacturer network Enable the ports to which your hubs and switches are connected hardware Check the switch configuration for optional VLANs applications Check for proxy or firewall settings that can block ports or protocols between source and destination devices For clien
414. orative approaches for sharing data in real time Your communications network should be open to support emerging services physical connections and components Because Ethernet TCP IP is so widely embraced in the commercial world its technologies are evolving much faster than proprietary networks leading to more alternative solutions and more affordable components A standards based Ethernet solution lets you move away from expensive proprietary systems while you maintain the security performance and availability required to support critical applications With proper planning and design you can improve processes reduce expenses and improve productivity 122 31006929 8 2007 Planning and Layout Open Standards In both the commercial and the automation domains Ethernet TCP IP supports all Support types of communication including Internet Web pages file transfer industrial messages other standards based services For every communication task you need to perform there is an existing service standard and managing organization Each of these services need to be run over the most suitable network layer The following list indicates some of the physical media and protocols supported by open TCP IP standards and the benefits they bring to industrial automation environments twisted pair copper cables for simplicity and low cost optical fiber for immunity to interference over long distances the IP protocol for the com
415. ork node all keystrokes on the remote are translated into keystrokes on the network node Used primarily with IPX protocol Form of remote access where the device dialing in acts as a peer on the target network Used with both IP and IPX protocols A network device that connects one Ethernet segment to another within the same local area network The repeater transmits signals both ways between the segments It amplifies the electrical signals regenerates the header of each packet extends packet fragments and performs auto segmentation and auto reconnection on ports with continuous collisions A network topology in which the nodes are connected in a closed loop Data move from node to node around the loop always in the same direction Remote Input Output CRP communications processor to the remote devices Network communications across the remote input output devices routing information protocol A distance vector protocol that uses distance in number of routing hops to calculate the best next path for a data packet A registered jack connector type used with twisted pair UTP STP e g RJ45 remote monitoring A subset of SNMP MIB II allows flexible and comprehensive monitoring and management capabilities by addressing up to 10 different groups of information remote monitor management information base The nine Ethernet levels of network management statistics reporting 31006929 8 2007 533 Glossary router route
416. ound around each other to cancel electromagnetic interference crosstalk The number of twists per meter make up part of the specification more twists produce less crosstalk The twisting of pairs the quality of the conductive material the type of insulator and the shielding largely determine the rate at which data can be transmitted LAN cables are generically called unshielded twisted pair UTP and are identified with a category rating The American National Standards Institute Electronic Industries Association ANSI EIA standard 568 is one of several standards that specify categories of twisted pair cabling systems wires junctions and connectors in terms of the data rates that they can sustain effectively The specifications describe the cable material and the types of connectors and junction blocks needed to conform to a category Category Maximum Usual application data rate CAT 1 up to 1 Mb Traditional unshielded twisted pair telephone cable that is suited for s 1 MHz_ voice It is not recommended for network use CAT 2 4 Mb s Unshielded twisted pair cable certified for data transmissions up to 4 Mbit s This cable has four twisted pairs This cable should not be used for high speed networking CAT 3 16 Mb s Rated for signals up to 16 MHz and supports 10 Mbit s Ethernet 4 Mbit s token ring and 100 VG AnyLAN networks The cable is twisted for noise immunity This cable is installed at many sites as tele
417. ow much EMC a product or cable can emit e immunity the degree of tolerance for EMC that a product or cable has The standards that apply depend on the environment for which you are designing your Transparent Ready system The two main EMC standards organizations are IEC and CENELEC The two main international standards for electromagnetic emission and immunity are e IEC 61000 6 2 1999 Electromagnetic compatibility Part 6 2 Generic standards Immunity for industrial environments e IEC 61000 6 4 1997 Electromagnetic compatibility Part 6 Generic Standards Section 4 Emission standard for industrial environments IEC 1000 4 The IEC 1000 4 standard establishes a common reference for evaluating the Standard performance of industrial process measurement and control instrumentation when exposed to electric or electromagnetic interference The standard describes interference susceptibility tests that demonstrate the ability of equipment to function correctly in working environments When determining the type of tests to run base your choices on the types of interference to which your equipment is exposed when installed Take the following factors into consideration e the method by which the electrical circuit and shields are tied to earth ground e the quality of the shielding e the environment Sections IEC1000 4 2 through 1000 4 5 see p 485 are discussed in more detail later in this manual 76 31006929 8 2007 Planni
418. ow value and do not send request to devices that are known to be unavailable If a device is normally polled every 5 s but has returned 2 errors in a row check that device only once every 30 seconds to see if it is able to respond again 310 31006929 8 2007 Services Overview Response Times Common Problems Response times for Schneider Gateway systems are shown in Appendix A see p 371 Common problems with gateway systems include e overloaded gateways caused by source network devices sending requests faster than they can be processed on the destination network e communications errors to one or all destination devices when a single destination device is removed caused by time outs that affect how quickly communications are processed on the destination network and produce overloads e timed out requests from the source device before the message is processed on the destination network caused by setting incorrect time out values or by a failure to consider the effect of message queuing in the gateway e inability to connect to the gateway because all the socket connections are in use 31006929 8 2007 311 Services Overview 3 16 Supported Services per Device Ethernet Services and the Transparent Ready Devices that Support Them Quantum Devices The following table lists the Ethernet services supported by the Quantum CPUs with embedded Ethernet ports and by the Quantum Ethernet communication
419. owing remote relational databases e SQL server e MySQL e Oracle This connection enables all internal or process data to be archived so that it can be logged and traced The data can be archived written periodically and or for a specific event These variables can be from PLCs I O bits internal bits internal words and registers or local to the module The FactoryCast HMI roll over function checks the size of tables by managing the maximum number of records It is a circular data archiving function that automatically deletes the oldest data The roll over function can be accessed by setting parameters in the FactoryCast HMI software Database characteristics are as follows number of databases that can be connected 3 number of tables that can be written per database 10 maximum number of columns per table 50 maximum type of database supported Oracle SQL Server and MySQL automatic table creation The FactoryCast HMI server automatically creates a table in the database The FactoryCast HMI server can perform various arithmetic and logical operations on a combination of variables from the HMI database independent of the PLC processor Some of these calculations include scaling formatting and logic processing for event triggering The calculation function comprises a set of spreadsheets with the formulae defined in cells The spreadsheets are interpreted and processed by the server The result of each formula is ass
420. pair cable shielded twisted pair cable and optical fiber cable TIA EIA 569 A 1995 Commercial Building Standard for Telecommunications Pathways and Spaces Specifies how to build pathways and spaces for telecommunication media TIA EIA 606 1994 Building Infrastructure Administration Defines design guidelines for managing a telecommunications infrastructure Requirements Standard TIA EIA 607 1995 Grounding and Defines grounding and equipotential bonding Bonding requirements for telecommunications cabling and equipment The TIA EIA standards define a structured cabling system that is designed and built in multiple blocks The blocks are integrated into a hierarchical network to create a unified communication system LANs represent blocks with lower performance requirements while backbone network blocks which require high performance fiber optic cable perform the work of connecting the blocks to each other in a star topology The standard also specifies the requirements for fiber optic cable single and multimode STP and UTP cable In general the TIA EIA 568 wiring standard provides e specifications for a generic telecommunications wiring system for commercial buildings e specifications for media network topology termination and connection grounding points and administration of wiring systems e support for environments that use several different products and vendors e information a
421. parent Ready network There are two additional concerns that relate to industrial Ethernet standards e Information Technology and Telecommunication groups such as TIA define standards for industrial Ethernet in addition to the traditional industrial standards organizations e Unlike industrial automation standards standards for industrial Ethernet infrastructure devices hubs switches routers etc cables and connectors not yet are clearly defined Many industrial Ethernet infrastructure devices have adopted the standards in use for industrial automation devices PLCs I O etc and present these standards as appropriate for Ethernet devices This section attempts to bring together the recommendations for environmental safety set forth by the emerging industrial Ethernet standards and the Information Technology and Telecommunications standards In addition to the recommen dations it is important to note e When you design an industrial Ethernet installation you must comply with the regulations set forth by your regional standards organizations both for the types of devices you plan to use and the applications you plan to target These standards usually provide well defined rules and guidelines for industrial automation devices e For cables and connectors emerging standards are being defined Industrial Ethernet organizations such as Modbus IDA and IAONA provide recommen dations for cables and connectors Other topics in t
422. performance parameter 514 pair to pair equal level far end crosstalk ISO IEC 11801 performance parameter 514 pair to pair near end crosstalk loss ISO IEC 11801 performance parameter 513 parameters for copper cable testing 510 password 149 performance parameters for Ethernet copper cable 510 performance standards 32 performance testing a copper installation 509 permanent link 116 physical connections troubleshooting an Ethernet system 346 pinout RJ45 connector for twisted pair Ethernet systems 80 pinouts for an RJ45 copper connector 88 M12 circular connectors 89 plant data transfer services 162 plant distributor 42 point to point link in an Ethernet system 62 point to point VPN 146 pollution levels ingress protection requirements 73 power sum attenuation of crosstalk ratio ISO IEC 11801 performance parameter 514 power sum equal level far end crosstalk ISO IEC 11801 performance parameter 514 power sum near end crosstalk loss ISO IEC 11801 performance parameter 514 PRI ISDN options 62 private MIB for network management 137 344 problem identification in an Ethernet system 346 propagation delay ISO IEC 11801 performance parameter 515 propagation delay scew ISO IEC 11801 performance parameter 515 PSACR power sum attenuation crosstalk ratio 514 PSELFEXT power sumequal level far end crosstalk 514 publisher in a global data operation 199 Q Quantum hot standby in a communication centric s
423. pervisor protocol e g levels 1 2 Ethernet IP to and 3 communicate with a third party device 162 31006929 8 2007 Services Overview Remote Data Transfer Services Service Level Response Data Transfer Exchange Examples Communications Common Time Frequency Confirmation Topology Use Electronic company minutes exception send maintenance one email client to mail level report up to confirmation no reminders many recipients notification level 1 several min delivery production FactoryCast confirmation reports HMI email FactoryCast company seconds 1 s 30 min sending one device to HMI database level production database connectivity level 1 reports and data directly to a database OPC company 50 ms exception confirmation SCADA server central OPC server level seconds report or per transaction to SCADA with Modbus TCPIP level 1 periodic clients to plant devices plant then OPC monitoring communicates system to plant data to other plant devices SCADA or HMI applications 31006929 8 2007 163 Services Overview Diagnostic Services Service Recipient of Single or Device or Plant Examples Communications Diagnostics Multiple device Diagnostics Topology Diagnostics Embedded people single internal device obtaining module several Web diagnostics information health and browser clients configuration information remotely with a Web brows
424. phone cabling CAT 4 20 Mb s Rated for signals up to 20 MHz and is certified to handle 16 Mbit s token ring networks The cable has four pairs CAT 5 100 Mb s Rated for signals up to 100 MHz at a maximum distance of 100 m 1000 Mb s Ethernet 100Base TX FDDI and ATM at 155 Mbit s use this cabling 4 pairs It has low capacitance and exhibits low crosstalk due to the high number of twists ft The predominant cable in new buildings since the early 1990s No longer supported replaced by 5E 78 31006929 8 2007 Planning and Layout Twisted Pair Cable Shielding Other Cable Characteristics Category Maximum Usual application data rate CAT 5E up to Enhanced CAT 5 has all the characteristics of CAT 5 but is 350 Mb s manufactured with higher quality to minimize crosstalk It has more twists and is rated at frequencies up to 200 MHz double the transmission capability of CAT5 However at these frequencies crosstalk can be a problem and the cable does not have shielding to reduce crosstalk This cable is defined in TIA EIA 568A 5 Addendum 5 CAT 6 up to Designed to support frequencies over 200 MHz using specially 400 MHz designed components that reduce delay distortion and other problems The TIA and ISO are cooperating on this category CAT 7 600 Designed to support frequencies up to 600 MHz Each pair is 700 MHz __ individually shielded and the entire cable is surrounded b
425. ponse trap or disable Settings are made using the web address The Ethernet ports of the Quantum Premium PLCs and ETG Gateway support access control lists for Modbus messaging They allow you to configure IP addresses that can send Modbus requests to the PLC They do not allow access to other protocols Use care when setting access control because it restricts the functioning of active Web pages that use Modbus to retrieve data Wireless networks suffer a great security disadvantage when compared to traditional networks Because a wireless network transmits over radio waves it is easier to get unauthorized physical access to it These options for wireless systems exist in automation systems e traditional wireless systems for Serial networks Modbus Plus and custom Ethernet solutions e wireless Ethernet based on office standards Systems based on non standard wireless are more difficult to intercept since they do not use standard protocols However systems using office based wireless can be intercepted using any laptop computer with a wireless connection putting them more at risk Each wireless network is given an SSID or network name to identify it Normally the SSID chosen is a logical name Do not choose a logical name such as the hardware vendor or your company name this gives information about the network An access point software or a device provides the connection hub for a wireless device connected to a cabled LAN
426. port or Modbus serial slave if a serial to Ethernet bridge is used e supports Modbus function codes 3 read registers 16 write registers and 23 read write registers depending on data that is exchanged The I O scanning service should be used when a central device needs to exchange data either read or write data with a remote device at a fixed reasonably fast rate Suitable applications include e fast repetitive communications e applications that call for communication between one device and many remote devices where different data is exchanged with different remote devices e applications that need to exchange data to more devices than is possible using the existing COMM blocks e automatic error handling e controlling I O devices e devices that need to exchange the same data with many devices but that do not support the global data service see p 197 Because of the network and device load produced by its data exchanges the I O scanning service should not be used for nonperiodic communications event triggered actions report generation or event notification because of the network and device load produced by its data exchanges The Modbus messaging service should be used in these situations 168 31006929 8 2007 Services Overview I O Scanner Operation Summary The I O scanning service is implemented as a separate stand alone communications task in either an Ethernet communication module or in a CPU wit
427. pplication range has a recommended cable category This table shows each of the classes and their associated application and cable category Class Application Class includes Permanent Link ANSI TIA EIA 568 and Channel Category A Speech band and low frequency specified up to applications 100 kHz Copper cabling permanent links and channels Supporting Class A applications are referred to as Class A permanent links and Class A channels respectively B Includes medium bit rate data applications specified up to Copper cabling permanent links and 1 MHz channels supporting Class B applications are referred to as Class B permanent links and Class B channels respectively C Includes high bit rate data applications specified up to Category 3 Copper cabling permanent links and 16 MHz channels Supporting Class C applications are referred to as Class C permanent links and Class C channels respectively D Includes very high bit rate data applications specified up to Category 5 No Copper cabling permanent links and 100 MHz longer recognized channels by TIA EIA Supporting Class D applications are Category 5e referred to as Class D permanent links and Recommended as Class D channels respectively the minimum for all future installations by TIA EIA IEEE Active Equipment Manufacturers Optical Includes high and very high bit rate data specified to Class applications support Optical fibre per
428. pply should include detailed information about component acceptance testing Such documentation includes e evidence of conformance for example for cables connectors and cable assemblies e cable acceptance test records and other information e cable assembly acceptance test records and related information e delivery information for example unique product identifiers of cables and components such as dates of receipt and batch numbers or identifier codes Before you begin choose a labeling scheme To match cable test results to corresponding components make sure that the name on the cable test matches the printed label on the patch panel or outlet For best results follow the guidelines for labeling described in Labeling Cables and Components see p 111 112 31006929 8 2007 Planning and Layout Recommen dation 4 Test Results Management It is important that you carefully organize and store your test data Proper management of test results is key to determining whether an installation is successful Test results validate the performance and EMC compliance of a cabling system allowing assessment of specific components and providing valuable historic data Performing accurate cabling tests is the only way to verify that your installation meets your original design requirements and conforms to regional and international standards Depending on the type of installation you may be required to include test data in
429. ps time locally At the next configured update the client requests the time from the server and synchronizes its local clock again The client s time accuracy is affected by the accuracy of its local clock and the update period More frequent time updates result in less time drift and therefore more accurate client time Service accuracy is also determined by the accuracy of the time server A time server can be from a Windows or a Linux PC to a dedicated time server with an atomic clock The time server maintains its time by using its local clock while receiving updates from a remote source like a GPS or a DCF receiver The internal clock s accuracy and the response time to NTP requests can affect the overall system accuracy A Windows PC acting as an NTP server typically restricts the system accuracy to 30 ms a dedicated NTP server with a GPS receiver is accurate to within less than 1 ms This service is better than earlier time synchronization systems because it requires only a single connection Earlier systems required each device to have a GPS ora DCF receiver resulting in higher costs and difficulty in placing antennas When a CPU acting as a client requests a time update the Ethernet module obtains this information from the server and updates the CPU s internal clock This internal clock now functions as the local clock for the PLC until the next time update This clock can be accessed at any time inside the user logic by using
430. ptions However the transmission of this authentication information is done in simple text and therefore it can be obtained by inspecting the content of the message 248 31006929 8 2007 Services Overview Quantum Device Support for Other Services SNMP FTP TFTP Device SNMP v1 SNMP v2 SNMP v3 MIB II TFprivate MIB 140CPU65150 X X X 140CPU65160 140NOE77101 140NOE77111 140NWM10000 X X X X xI X X X lt lt X Xx Xx Device Firmware Web Files Security FDR Support 140CPU65150 X X X X 140CPU65160 140NOE77101 140NOE77111 X X X 140NWM10000 X X X X x Xx Xx Xx X X X X Device FDR Support 140CPU65150 X 140CPU65160 140NOE77101 140NOE77111 140NWM10000 xX Xx OK Xx 31006929 8 2007 249 Services Overview Telnet Device Configuration Diagnostics Security Levels of Security 140CPU65150 X X x2 140CPU65160 X X x2 140NOE77101 G X X x2 140NOE77111 X X x2 140NWM10000 X X x2 1 For factory use only 2 multiple passwords 250 31006929 8 2007 Services Overview Other Services Supported by Premium Devices
431. quirements of an installation the structure and minimum configuration for a generic cabling system 484 31006929 8 2007 Standards and Considerations Electromagnetic Compatibility Standards The standard does not cover specifications for cables used to connect application specific equipment to a cabling system Standard guidelines relate to performance and length of cables only as these have the most significant impact on transmission quality Safety and EMC are also not covered in the standard Related information in the ISO IEC 11801 standard however may be useful in understanding regulations encountered in other standards documents For a cabling installation to conform to the IEC11801 standard the configuration must connect the following subsystems to create a generic cabling structure e Campus backbone uses a campus distributor e Building backbone uses a building distributor for each building e Horizontal cabling uses floor distributors The main EMC standards organizations are e IEC International Electrotechnical Commission Geneva e CENELEC European Committee for Electrotechnical Standardization Brussels There are two major international standards for electromagnetic emission and immunity e IEC 61000 6 2 1999 Electromagnetic compatibility EMC Part 6 2 Generic standards Immunity for industrial environments e IEC 61000 6 4 1997 Electromagnetic compatibility EMC Part 6 Generic S
432. r Response Time ms 10 lt 1 10 20 50 70 100 Requests Sent PLC Cycles to Receive Response 1 2 2 3 5 5 8 2 2 3 4 10 11 17 3 2 4 6 15 18 26 4 2 4 8 19 24 35 5 3 5 10 24 31 44 6 3 6 12 28 37 54 7 3 7 14 33 43 63 8 3 8 15 37 50 72 9 4 9 17 42 56 81 10 4 10 19 47 63 90 11 4 11 21 51 69 100 12 4 12 23 56 76 109 13 5 13 25 60 82 118 14 5 14 48 65 88 127 15 5 17 48 80 106 144 16 6 17 48 80 106 146 17 6 17 48 80 108 155 424 31006929 8 2007 Modbus Client Performance Modbus Client Response Times Quantum 140 CPU65150 with a 140 NOE77101 Ethernet Communications Module Test Setup The following charts show Quantum PLC response times where the client request block is triggered in PLC logic by reading data from a Modbus server The graphs represent the number of CPU cycles required for the PLC to complete all triggered Modbus client requests In all cases the PLC is a Quantum 140 CPU65150 with a 140 NOE77101 Ethernet communications module The CPU logic scan times vary Modbus client response times are tracked with respect to six Modbus server response times lt 1ms 10 ms 20 ms 50 ms 70 ms o e 100 ms 31006929 8 2007 425 Modbus Client Performance At a CPU Scan Time of 200 ms CPU Cycles 2 100 ms 170 ms 100 ms 50 ms 20 ms 50 ms 20 ms 100 ms 1
433. r determines the data destination and sends all data to all ports Note These solutions result in data transmission to Ethernet ports that do not normally receive data when the network is not under analysis This can result in increased traffic on the network among other undesirable results Finding the error packets within a capture capturing data for intermittent errors causes files of excessive size For errors that occur every few minutes or hours a capture setup may have to run for several hours This creates many thousands of packets in the file that has to be analyzed during error investigation Because such a large file consumes hundreds of MB of disk space it is impractical to run an analyzer for 24 hour periods Therefore an error may not necessarily occur when the analyzer happens to be running To avoid this the packet capture tool can be set to limit the duration of data collection or the number of packets in the capture file At the predefined limit the file closes and the tool starts a new file After the configured number of files have been created the tool either stops recording or begins to overwrite the files in order in which they were created Each such file is time stamped when the tool closes it Using a SCADA system or other plant system to record error times for example plant stoppage or and unavailable device you can open the correct file to find packets that were exchanged at the time of the error
434. r hop routing routing bridge routing protocol routing table routing update RTPS Device capable of filtering forwarding packets based on data link layer information Whereas a bridge or switch may read only MAC layer addresses to filter a router can read data such as IP addresses and route accordingly Unlike bridges routers operate at level 3 the network layer of the OSI model Also unlike bridges routers are protocol specific acting on routing information carried by the communications protocol in the network layer Bridges pass layer 2 data link packets directly onto the next segment of a LAN whereas a router can use information about the network topology and so can choose the best route for a layer 3 packet Because routers operate at level 3 they are independent of the physical layer and so can be used to link a number of different network types They have to be able to exchange information between themselves so that they know the conditions on the network which links are active and which nodes are available The route between one router and the next all data packets specify the number of hops after which the packet will be dropped and an error message sent to the data source The process of delivering a message across a network or networks via the most appropriate path While simple in principle routing uses a specialized complex science influenced by a plethora of factors The more networks are joined together t
435. r of Registers 80 100 The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 200 EGX200 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 400 8333333 1894 166667 3600 833333 394 1666667 1840 833333 3494 166667 187 5 16 450 8333333 2294 166667 4400 833333 419 1666667 2040 833333 3894 166667 187 5 32 504 1666667 2720 833333 5254 166667 445 8333333 2254 166667 4320 833333 187 5 64 610 8333333 3574 166667 6960 833333 499 1666667 2680 833333 5174 166667 187 5 100 730 8333333 4534 166667 8880 833333 559 1666667 3160 833333 6134 166667 187 5 450 31006929 8 2007 Gateway Performance Serial Devices with 500 ms Response Time Time ms 16000 4 14000 4 12000 10000 4 8000 6000 4 4000 2000 4 20 40 Number of Registers 100 The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 500 EGX200 Time to Complete All Requests Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Registers Time 1 700 8333333 4294 16667 8400
436. r should be configured for any security or firewall settings that are required A modem is added to the remote client The remote client is configured for dial up access Whether your company requires a dedicated RAS server with security and firewall features or just a simple Windows NT server or workstation consider the following security and system factors in your network design support for external modems Some standalone RAS servers do not support serial style modem connections security verification including Chap PAP or Windows authentication Many systems provide an additional security layer before the user can access a Windows style network If there are no Windows servers on the network the RAS server becomes the main verification point dial back so that the RAS server and modem can be configured to dial a user back at a pre configured phone number This security feature requires that anyone attempting to access the system be at a specific phone number The client dials the RAS server and enters a name and password the RAS server hangs up and dials the user back at a fixed phone number While this feature provides excellent security it can also be a very limiting option When an OEM ships a dial back machine to a customer the end user pays most of the cost of the RAS connections because the phone connection is initiated from the PLC end of the line allowed protocols Many RAS servers can be configured to allow only specifi
437. r switches in line Topology and considering each one of them as the connection for a device A limited number of hubs and an unlimited number of switches can be interconnected to achieve this purpose O Q 5 e Re e el an ai go an OB an GB an a ao a an a as a ab C SOUL Emel v 1 Ethernet switches 2 Ethernet devices 31006929 8 2007 49 Planning and Layout Ethernet Star Topology Ethernet Daisy Chain Topology In an Ethernet star the intermediate device may be a hub or a switch A star is the most commonly used topology in office networks and has been adopted in most automation applications For industrial Ethernet applications the use of a full duplex switch as the central device rather than a hub is strongly recommended es 1 Ethernet switches 2 Ethernet devices To develop an Ethernet daisy chain network devices with dual Ethernet ports are required Schneider Electric is releasing industrial Ethernet devices with this type of functionality dual Ethernet ports for daisy chain connectivity at the present time D0000 50 31006929 8 2007 Planning and Layout Ethernet Ring Ethernet rings usually
438. re e SCADA e remote programming e security For corporate private networks several considerations are important with respect to a remote access capability reliability performance scalability manageability secure connectivity through encryption and or authentication of users and devices accessibility 31006929 8 2007 141 Planning and Layout Remote Access Types Direct Dial up to the Device Remote Control of a PC via Dial up Network Access Connection of the PLC to the Internet Direct dial up is handled by a modem attached directly to a plant PLC or other device An operator is able to dial into the modem and access the device port as in a local connection The operator is restricted to serial protocol access to only a single PLC or device via Modbus Remote control dial up involves taking control of one of the PCs on the site The remote operator actually uses the PC on site All inputs from the remote keyboard mouse are sent to the site PC and the screen image of the site PC is shown on the remote PC Network access involves extending the Ethernet network to a remote station It may be implemented using either a RAS server or by VPN The Ethernet connection allows full access to all PLCs and other devices on the site s Ethernet The remote station can access Web pages implement diagnostics do programming connect to network printers and access documents from servers When a connection
439. rect version of OFS MonitorPro v7 2 without access to the structured variables 31006929 8 2007 271 Services Overview Build time Runtime Architecture for a System with Multiple SCADA Connections Sample The following example of a build time runtime system supports architectures that Architecture require e frequent application modifications e ahigher level of service for synchronization between the SCADA and the running application during modifications This architecture also supports multiple SCADA connected on one centralized OFS The synchronization is managed through dynamic exchanges between OFS and Unity Pro XL Manual operation is not needed to update the symbols file for OFS x PC server with STU application files Unity Pro SODA Unity Pro Unity Pro OFS Synchronization by dynamic exchange One PC is used to run both OFS and Unity Pro XL in server mode One or several PCs are dedicated for the SCADA Another PC is used to run Unity Pro for application modifications The PC server for the STU application files provides the consistency needed so that all the stations running Unity Pro can access the same up to date application information 272 31006929 8 2007 Services Overview System Option Key Character istics of the System Product Versions The STU application fil
440. request Repetition Rates Repetition rates are limited by the I O scanner device A Quantum NOE Ethernet Internal Clocks communications module has a 17 ms clock rate A Premium ETY Ethernet communications module or a Unity CoPro CPU with an embedded Ethernet port Quantum or Premium has a 10 ms clock rate The clock rate limits the time resolution in which an I O scanner request is sent to a remote device When the configured repetition rate is 0 ms the system sends requests as fast as possible Ina Quantum NOE system requests are sent after the data is transferred at each end of scan EOS A Premium or Copro system sends requests as frequently as a remote device can respond to the previous request When the repetition rate is configured for a value greater than 0 ms the rate is rounded up to a multiple of 10 ms on a Premium or a Unity Copro system or 17 ms on a Quantum system For example a Premium system with a configured repetition rate of 35 ms sends a request every 40 ms providing the end device has finished responding A Quantum NOE system configured for a 25 ms repetition rate sends requests either every 34 ms or once per PLC scan whichever is greater 174 31006929 8 2007 Services Overview A Comparative Example EOS Time EOS CPU logic EOS The following chart compares effective repetition rates for Quantum Premium and Unity CoPro systems over multiple scans Quantum NOE CPU NOE Remote
441. requires updating 31006929 8 2007 111 Planning and Layout Cabling Documentation Introduction Creating Documentation Recommen dation 1 Commercial Installations Recommen dation 2 Component Acceptance Testing Recommen dation 3 Cabling Identifiers The ISO IEC 14763 1 and EN 50174 1 standards describe the specifications for documentation of cabling This section summarizes the guidelines and requirements specified in standard EN 50174 1 2000 chapter 6 1 and provides recommendations for managing documentation When installing cabling you need to create documentation both during and following the installation This documentation needs to provide sufficient detail about the installation specifications The recommendations presented here can help you determine the level of documentation that is appropriate for your installation Note You should maintain the same level of documentation detail throughout the design and installation phases Commercial documentation should include any technical and contractual information that relates to end user requirements and the installation undertaken It should also include the following Installation specification See standard EN 50174 1 200 chapter 5 2 Quality plan See standard EN 50174 1 200 chapter 5 3 Final cabling documentation See standard EN 50174 1 200 chapter 6 2 When appropriate the documentation you su
442. resents cabling standards for an industrial Ethernet network It also describes layouts for a Transparent Ready industrial network To assist in understanding this structure basic network topologies are reviewed LAN technologies and issues relevant to an industrial Ethernet network are discussed as are WAN technologies and hardware What s in this This section contains the following topics Section Topic Page Industrial Ethernet Cable Planning 35 Structured Cabling Standards 36 Cabling in a Transparent Ready Industrial Ethernet System 40 Understanding Basic Network Structure 43 Developing Network Architecture for Industrial Ethernet Networks 49 Redundant Ring Topology 53 LAN Technologies and Network Design 55 LAN Hardware 59 Other LAN Considerations 61 WAN Technologies and Network Design 62 WAN Hardware 65 34 31006929 8 2007 Planning and Layout Industrial Ethernet Cable Planning Introduction Because there are as yet no defined standards for the physical layout of an industrial Ethernet network Schneider Electric has chosen to conform to the recommen dations submitted by standards organizations such as Modbus IDA IAONA PNO and the work in progress by the IEC An industrial manufacturing site is a physical facility in which manufacturing or process control activities take place In most cases the site consists of multiple buildings or plants that manage interconnected but separate processes The physic
443. rk By equipotentially bonding earthing proper wiring and shielding your site and equipment you can significantly reduce a large percentage of EMI issues For more information on EMC see the environmental requirements section see p 67 For more information on EMI see EMI see p 489 The following list describes key measures you need to consider in your installation in order to reduce EMI in an industrial Ethernet network earthing and equipotential bonding EMC compatible wiring and cable runs balancing circuits cable selection shielding filtering placement of devices placement of wires transposition of outgoing and return lines electrical isolation Earthing is the method used to carry an electric charge to the ground earth along a conductive path Examples of conductors include a wire metal conduit or metal cabinet Equipotential bonding is the process of connecting conductive parts in order to create a low resistance electrical contact for direct current and lower frequency alternating currents This interconnection spreads the flow of interference over multiple paths so that it avoids any one junction In most cases an equipotential bonding system is earthed The flow of interference terminates in the earth The flow of an electric charge is dispersed into the ground and away from sensitive equipment and communication lines The EN 50310 standard requires buildings with information systems to be fitted with
444. rmanent globally unique IP address is required for the PLC this may not match the address used on your local system e There is no easy way to limit access to the PLC unlike using callback for a RAS server although firewalls can be used for access control 31006929 8 2007 147 Planning and Layout General Internet System Setup General system setup is as follows e A local ISP needs to be found to provide a permanent connection from the PLC to the Internet This can be very expensive as most permanent connections use methods other than modems If you are planning to use a modem consult with the ISP and phone company to check that a phone connection can be left connected indefinitely e Obtain a permanent unique IP address for your PLC For small companies this address may be obtained through your ISP Leasing this address from your ISP may be expensive as there are a limited number of these addresses worldwide and the ISP can either lease an address to a single user or share this address with many users Larger companies should already have a series of these addresses e Have your ISP or IT staff configure any routers that are needed to access this IP address from the rest of the Internet Also configure the PLC s IP address and gateway e A firewall see p 150 should be installed to separate the portion of the network connecting your PLC to the Internet and the rest of your network This is done to prevent users accessing
445. ror occurs in the application layer when the time to recover is longer than the application layer timeout detecting lost packets There are two ways to detect lost packets sent received packet counter Use this method when you can verify that one packet is sent for each one received for example a system that only has Modbus client server traffic Counters are also suited for detecting large numbers of lost packets e Ethernet packet capture tool Use this method to see the TCP sequence and acknowledgment numbers to identify lost packets Packet captures should use the timestamp feature to correlate the time of packet loss with the alarm time on a SCADA system or time of a problem in the plant Responding to packet loss packet lost in a switch or network device You see this error when a packet appears on one side of a switch but not the other This requires the simultaneous implementation of two packet capture tools To resolve this check the switch load Network devices discard some packets when the switch is overloaded Electrical noise can also cause packet corruption forcing a packet to be discarded packet loss causes an application error If a packet loss causes an application error e extend the application timeout to allow for the recovery of TCP layer e modify the devices for faster TCP layer recovery requires a firmware change e reduce the number of packets lost Sample ways to reduce t
446. rrupted packets Each specific instance of a managed object is called a MIB variable Most devices support MIB II with some extensions for switches A private MIB installed in addition to the standard MIB is supplied by a vendor and is specific to that vendor s products Schneider has a set of MIBs to load into a management package in order to manage devices In order to set up a network management system load the MIB file into the manager The manager knows the required data and addresses needed to discover the devices on the network It will feed the MIB files and begin to monitor the network 31006929 8 2007 137 Planning and Layout Security Effects on the Network A community string configured on a router or switch is a password that defines a community of end users that can access SNMP information on a network device The community string should be an alpha numeric string of at least 8 characters Designating access to devices in this way aids in providing security for your network Security in the latest SNMP version v3 controls e the modification of information e masquerading e the modification of the message stream e the disclosure of information SNMP version 3 provides better security features than versions 1 and 2 When setting up a network management system be aware of the effect that the system might have on network speed and congestion If you program the system to monitor the network at
447. rting It is not practical for a field device to individually monitor a great number of variables to determine if an exception report is required Most systems use a checksum on a group of variables A backup write should always be implemented because the checksum can fail For example multiple variables may change in a way that makes the checksum stay the same The field device can reduce device and network loads by applying hysteresis to the variables and sending an exception report only when a variable changes by a predetermined amount If you use a SCADA system that does not implement a Modbus messaging server or a field device that does not implement a Modbus messaging client the SCADA system polls only the checksum or a single bit to indicate that one or more tags ina block of data has changed When a change is detected the SCADA polls the entire data set to obtain the new values This system is not normally supported natively within the SCADA system You must code it using some form of user logic within the SCADA system To poll for field status the SCADA package reads data from each field device Normally the SCADA package determines how the data is polled based on either e user defined groups e SCADA created groups If you set up the groups you must take into account how variables are grouped and their corresponding addresses in the field devices how often the groups are polled compared to the rate at which they are answered
448. rward until they almost touch The plastic jacket should be the front of the jack positioned about 3 8 in inside the jack 7 Insert the jack into the crimper and firmly If you do not get a good crimp the first squeeze the crimper until the jack is securely time reposition the crimper and try crimped to the cable end again 8 Inspect the jack to make sure you have a Look at the front end of the jack to secure crimp make sure the copper connections are not pressing down into the wires Look at the back of the jack to make sure the plastic jacket extends into the jack about 3 8 in Note It is very important to make sure no wires extend out of the back of the jack Making an Ethernet fiber cable requires special procedures and tools Consult a trained and certified technician for assistance 110 31006929 8 2007 Planning and Layout Cabling Administration Introduction Standard EN 50174 1 and Identifiers Labeling Cables and Components The EN 50174 1 standard describes the specification for cabling administration Cabling administration includes the management of identification codes and methods cable and component labeling label application and location durability and quality of labels inspection and label updating Currently there is no international standard for these areas of cabling For general guidelines about cable labeling and identifiers refer to chapter 7 2 and 7 5
449. s Topic Problem Solution Function All network servers do not support all function codes A server that receives an Choose a code unsupported function code will usually respond to the client with an error message supported Error indication function code e client reports the error to correct the e user finds the error by inspecting the network packet for either the absence of a error response or a Modbus exception response Examples of newer Modbus function codes that can cause this error FC23 read write registers Quantum and Premium I O scanners use FC23 when read and write data are listed on the same line e Ethernet statistics or identification Request not A socket connection to the server can not be established because of accepted controlled access a firewall the number of available server sockets is exceeded Register If a request is sent to a nonexistent register area or to a range of registers that contain area not nonexistent registers the server can either respond with an error code as the Modbus supported specification expects or discard the request This error is detected through the Modbus error response report examination of the documentation on the supported registers The common cause of this error is when SCADA or administration personnel try to read multiple blocks or registers in a single request from a server that implements specific registers with gaps of unsupported registers between th
450. s Copper Cable Single mode fiber has a small core diameter about 3 5 x 10 4 in or 9 um and transmits infrared laser light wavelength 1300 to 1550 nm it provides only one optical mode that forces light along a linear path through the cable end and allows significantly more bandwidth than multimode Single mode fiber cable is often used in laser based long distance interoffice LAN applications cross country networks and international submarine links SIngle mode cables used for long distance networks can include 100 to 800 fibers cable The advantages of single mode fiber are a higher data capacity low attenuation and low fiber cost It is the most expensive cable and is harder to handle but has the highest bandwidth and distance ratings The advantages of multimode fiber is a lower connection and electronics cost that can lead to lower installation costs Fiber optic cable has several advantages compared to copper wire cable Fiber optic cable is selected for use in backbones and other areas of LAN and Ethernet networks The advantages are e Lower cost Optical cable is less expensive to make than copper wire of an equivalent length e Higher information capacity There are more optical fibers bundled in a cable which means more information can flow over an optical cable than a copper cable of similar diameter e Less signal degradation Optical fiber has less signal loss over equivalent distances than copper wire e
451. s 174 international standards for industrial Ethernet 29 Internet connection to a PLC for remote system access 142 147 Internet group management protocol 136 Internet group management protocol snooping 136 Internet suite of protocols 128 internetwork layer in the TCP IP model 126 of the Transparent Ready model 127 inter PLC level communication 155 IP address management in a Quantum hot standby system 301 IP code for degree of ingress protection 74 ISDN in an Ethernet system 62 ISDN terminal adapter in an Ethernet WAN 66 ISO IEC 11801 performance parameters attenuation of crosstalk ratio 514 DC loop resistance 515 equal level far end crosstalk 514 far end crosstalk 514 insertion loss 512 longitudinal to differential conversion loss 515 near end crosstalk loss 513 nominal impedance 512 power sum attenuation of crosstalk ratio 514 power sum equal level far end crosstalk 514 power sum near end crosstalk loss 514 propagation delay 515 propagation delay scew 515 return loss 512 ISO IEC 11801 standard copper cable testing definitions 509 for planning and installing copper cable 494 ISO IEC 8802 3 Ethernet standard 32 L labeling cables components 111 labels cabling 112 LAN technologies for Ethernet systems 55 leased line in an Ethernet system 62 light industrial environment crush requirements 70 degree of ingress protection 75 flexing requirements 70 humidity range 72 operating
452. s 32 51 108 209 409 382 31006929 8 2007 I O Scanner Performance Premium I O Scanner Response Times PLC Memory to Remote Output Measurement The set of curves below illustrates Quantum PLC response times when a signal is Setup sent from the PLC to a remote output module Response Time The signal is written to a Momentum output module with a response time of 2 ms Results are plotted for 1 8 16 and 32 devices 31006929 8 2007 383 I O Scanner Performance TSXP575634M The TSXP575634M CPU used for the following measurements is at version 2 0 with CPU with its embedded Ethernet port at version 2 0 Embedded Ethernet Port 250 200 150 4 1004 N o E 504 1 16 devices 0 r r r r 0 50 100 150 200 PLC Scan Time ms The bottom curve shows that the response times for 1 to 16 devices are within 1 to 2 ms of each other The response times for 32 devices are 2 to 4 ms longer initially as scan time increases the difference in response times becomes larger The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from PLC Memory to Scanned Device Output ms TSXP575634M v2 0 10 ms 20 ms 50 ms 100ms 200 ms Embedded Ethernet Port v2 0 Scan Scan Scan Scan Scan 1 device 12 23 54 104 204 8 devices 13 23 55 105 205 16 devices 14 25 55 105 206 32 devices6 16 29
453. s designed with no customizing possible Typical SCADA systems use a combination of 3 methods with several sockets in use and one or more requests on each socket Commonly one or more sockets are set up for reading and writing data A request queue can form in both the end device and the SCADA system 31006929 8 2007 281 Services Overview One Requestata The efficiency of the SCADA system in sending requests and processing responses Time has a large impact on the system response time Here is an example of a single socket that supports one request at a time E OD 7 Only one request answered at a time FR e a C E E C EE A n A ez gt O m E ance a a Unused capacity for 15 u additional answers sent _ E Sa OC E j Sa SS A a Hx as E L The SCADA system only opens a single socket to the field device and is able to send only a single request It waits until this request is answered before the next request is sent This prevents overload in the end device by limiting the system to only one request at a time in the end device It also severely affects system response time For example if the SCADA system has 10 requests to send to the end device the end device takes 100 ms to answer each request and an additional 50 ms to send the new request The overall time to answer all requests is 1 5 s 282 31
454. s located in the same electromagnetic environment Because network wiring and equipment can be susceptible to and emit EMI it also requires that the immunity level of equipment and devices be such that they are not disturbing and not being disturbed by other equipment in the environment EMlis any electromagnetic phenomenon capable of impairing the performance of a device equipment or system It certain cases the interference can be significant enough to damage the equipment beyond repair In communication networks unwanted EMI is simply an unwanted electrical signal that is added to the useful signal This unwanted signal is sourced by conductions in conductors and by radiation in the air The terms EMI and disturbance mean essentially the same thing A disturbance can be caused by an electromagnetic phenomenon such as electrical voltage electrical current and electrical or magnetic fields It has a broad amplitude and frequency range over varying amounts of time It results in the reduced ability of susceptible equipment to function Electromagnetic influence occurs each time a disturbance is transferred from an interference source through one or more coupling mechanisms to susceptible equipment An interference source can be any device or equipment component that emits an electromagnetic disturbance such as electrical wiring cables and communication devices regulators and relays and electric motors Susceptible equipment is any d
455. s modules Service 140CPU65150 140CPU65160 140NOE77101 140NOE77111 140NWM10000 I O Scanner Modbus Server Modbus Client X X Global Data FDR Server X X X Xx X X X Xx X X X Xx XxX X X X Xx FDR Client BootP Client x lt x lt x lt Time Synchronization E mail Notification Web Embedded Diagnostics x Xx x Xx FactoryCast Web Server x x x x x FactoryCast HMI Web Server SNMP FTP Server TFTP Server x x Xx x x Xx x x Xx x X Xx Telnet Server x 1 For factory diagnostic purposes only Premium CPUs embedded Ethernet ports The following table lists the Ethernet services supported by the Premium CPUs with Service TSXP571634M TSXP572634M TSXP573634M TSXP574634M TSXP575634M 1 0 Scanner Modbus Server Modbus Client Global Data FDR Server XxX Xx x Xx Xx K XxX x x Xx XxX Xx x Xx Xx lt Xx Xx Xx Xx XxX XxX x Xx Xx FDR Client 312 31006929 8 2007 Services Overview Service TSXP571634M TSXP572634M TSXP573634M TSXP574634M TSXP575634M BootP Client xX X X X X Time Synchronization E mail Notification X X X X X Web Embedded Diagnostics X X X xX X FactoryCast Web
456. s not guarantee that all the variables in a group will be accessed in the same CPU scan if the group is transcribed on several communication requests An OFS mechanism ascertains the number of requests necessary to access the whole of a group of items for synchronous groups only The conditions that permit the items in a group to be consistent with one another read or written in the same CPU scan are described in the OPC Factory Server manual OPC OFS EXE Application Code Interfaces OPC Server OPC Group OPC read write Sync OPC Item Writing data OPC Item Synchronous Update OPC Item Back to Application Code R W Request Client Application is blocked during the time the server gets data DEVICES 31006929 8 2007 261 Services Overview Asynchronous Services Notification Service In asynchronous mode a request for any asynchronous operation receives an immediate response The operation requested has either been refused incorrect code response or is underway correct code response it has not been completed The completion and the outcome of the operation is announced via the notification mechanism This mechanism must be activated before starting an asynchronous operation Read Write Refresh and Cancel operations are used to partially or completely read and write a group of items The client application must periodically scan the evolution of variables read polling The client
457. s service redundancy from a system perspective Total system redundancy is affected by the network the devices and the service redundancies What s in this This section contains the following topics i Section Topic Page Network Redundancy and Communication Services 288 Redundancy within a SCADA System 292 SCADA in a Quantum Hot Standby System 295 Hot Standby Swap and Ethernet Services 302 31006929 8 2007 287 Services Overview Network Redundancy and Communication Services Summary Multiple Ethernet Interfaces ina Device Redundancy allows the network to continue to carry data in the event of the failure of a network component or cable When a failure occurs some amount of time elapses before the failure is realized and corrected by the network components This correction may or may not occur before other systems notice the problem Data being carried across the network may or may not be lost during the failure If data is lost it must be retransmitted If the network can recover before the time out time for a service and if no data is lost during the break recovery the services are not affected If the network cannot recover before the service time out time the service abandons the individual request The service may or may not retry the transfer depending on the service but you will experience some delay in the information transfer If the service implements retries you do not notice an appli
458. s to these questions in mind when you use the troubleshooting tables Topic Description Examples Network issues Problems with e physical connections of devices e logical addresses e transmission of Ethernet packets to and from devices e No light link Ethernet on device e Cannot ping device e Cannot contact device improvement for SCADA systems Services Problems with one or more Transparent Ready Modbus communications failure but web services A ping command can find the device pages are OK and get a response but other communications I O scanner failure but programming is OK to the device may fail SCADA system Specific information on performance SCADA system is slow to report field device status or execute commands Ethernet to serial bridges Specific information on troubleshooting communications through Ethernet to serial bridges Bridge operation is slow or communications to all devices are intermittent after a single device failure Ethernet packet capture tool Specific information on capturing and analyzing Ethernet packets for detailed troubleshooting 344 31006929 8 2007 Troubleshooting 4 2 Network Troubleshooting At a Glance Introduction This section describes network troubleshooting mostly for layer 1 the physical layer and layer 2 IP problems of the TCP stack What s in this This section c
459. smission medium composed of two glass optical or plastic fibers that transmits digital signals in the form of modulated light pulses from a laser or LED Features a thin filament of glass typically 125 to 140 um in overall diameter Because of its high bandwidth and high immunity to interference fiber optic cable is used in long haul or noisy applications A computer that stores data for network users and provides network access to that data With respect to Ethernet a process whereby a switch or bridge reads the contents of a packet and if it finds that the packet does not need to be forwarded drops it The filtering rate is the rate at which a device can receive packets and drop them without any loss of incoming packets or processing delay A router or workstation with multiple network interfaces that controls and limits specific protocols types of traffic within each protocol types of services and the direction of information flow The operating system OS of a device fiber optic inter repeater link Signaling methodology based on the IEEE 802 3 fiber optic specification 31006929 8 2007 523 Glossary forwarding fragment fragmentation Process whereby an Ethernet switch or bridge reads the contents of a packet and passes the packet on to the appropriate attached segment The forwarding rate is the time that it takes the device to execute all of the steps With respect to Ethernet a piece of a larger packet
460. ss consists of two parts the network address and the host or device address The subnet mask is a filter that is applied to the IP address to determine which part of the IP address is the network address and which part is the host or device address The network address is the part of an IP address that identifies the subnet that the address is a part of The mask is a 32 bit value that uses one bits for the network and subnet portions and zero bits for the host portion In classful addressing the network address portion of the IP address consists of one two or three octets starting from the left IP Address 11000000 10100000 00010100 00110000 192 160 20 48 Subnet Mask 11111111 11111111 11111111 00000000 255 255 255 0 Network Portion of 11000000 10100000 00010100 00000000 192 160 20 0 IP Address In classful addressing these are the possible classes of IP addresses to use depending on the size of your enterprise Class A 0 0 0 0 8 through 127 0 0 0 8 Class B 128 0 0 0 16 through 191 255 0 0 16 Class C 192 0 0 0 24 through 223 255 255 0 24 Class D 224 0 0 0 through 239 255 255 255 is used for multicasting see p 135 The remaining addresses known as Class E are reserved for experimental use 130 31006929 8 2007 Planning and Layout Classless Addressing Choosing an Address Range Special Addresses An address comprises 2 parts e the network inform
461. ssaging requests received during the CPU scan are answered at the end of that current CPU scan The PLC takes several CPU scans to answer an initial request a TCP socket needs to be established which takes several CPU scans Time Client Server Syn Scan Request Initial requests take two CPU scans rm Scan Request Additional requests take one CPU scan Response Scan Request Scan Eo Scan v Quantum PLC The response time of the Quantum PLC system is dependant on the number of System requests being processed The system answers requests using three independent methods e direct access to the CPU memory by the NOE modules e passing of requests to the CPU from the NOE modules e direct access using an embedded Ethernet port on the CPU Each method allows the PLC system to answer a specified number of requests per CPU scan All requests arriving at the Ethernet module are placed in the queue for that module each Ethernet port has its own queue At the end of the CPU scan the requests from the top of the queue are answered Any unanswered requests remain in the queue and are answered in the order they are received New requests placed in the queue can take one or more scans to move to the top of the queue 322 31006929 8 2007 Services Overview If no requests are currently in the queue the response time for a new request arriving at the PLC system is between 0 ms and one CPU scan depending on when during the
462. ssigns the IP address of the Ethernet communications module in the primary PLC to the Ethernet communications module in the standby PLC The changeover is transparent to other network devices After closing the current client server and I O scanner connections on Ethernet using a reset each Ethernet communications module sends a UDP changeover message to the Ethernet communications module in the other PLC The Ethernet communications module that sent the message waits for the response from the other Ethernet communications module or for a time out of approximately 500 ms As soon as the message is received or after the time out the IP address changes over 302 31006929 8 2007 Services Overview During the changeover any Modbus messaging communications currently in progress either client or server are aborted and must be resent Any MSTR or read write blocks in the PLC application must be retriggered and any remote requests e g SCADA must be resent by the remote device I O scanning needs to re establish the MAC address using ARP requests and socket connections to each remote device before data transfers resume The time required depends on the time it takes the remote device to respond to the new socket open request Note Each line in the I O scanner is an independent entry each begins data transfers at different times The IO scanner needs only the MAC address and socket for the device listed on a line before it star
463. sstalk NEXT value due to transmitting pair larger number less crosstalk Signal in response pair affected by attenuation D _ Xo___ ____ larger number p more attenuation Attenuation value smaller number less attenuation The illustration shows two Ethernet pairs transmit and receive When the transmitting pair is energized it generates crosstalk to the receiving pair At the near end the signal in the receiving pair is the lowest and therefore more susceptible to the NEXT influence As the value of NEXT increases the value of attenuation also increases Twisted pair cables were developed to avoid crosstalk and allow opposing fields to cancel each other The more twists there are the better the cancellation and the higher the frequency supported by the cable Often the NEXT of a permanent link or channel decreases indicating increased crosstalk due to poor installation termination of cables To connect the cable to a device you must untwist the cable to access the wires Untwisted wires increase crosstalk You can minimize crosstalk by retaining the cable pair twists as much as possible when you terminate the cable and connect it to hardware 31006929 8 2007 513 Earthing Grounding Procedures Power Sum NEXT PSNEXT Pair to pair Attenuation of Crosstalk Ratio ACR Power Sum ACR PSACR Far end Crosstalk Pair to pair Equal level Far end Crosstalk Power Sum ELFEXT PSELFEXT Pow
464. st important Installation practices are most important 31006929 8 2007 Standards and Considerations Copper Connector Standards Activities Current Activities Light Duty Industrial Connector Recommen dations Heavy Duty Industrial Connector Recommen dations The IEC Subcommittee SC 48B is responsible for standardization of electronic connectors based on the requirements of IEC committees such as ISO IEC JTC 1 SC 25 standards for office and similar environments and its Industrial Premises Cabling Task Group These groups work together with the Subcommittee SC65C Digital Communication and are called the SC65C JWG10 joint working group The SC65C JWG10 working group s mission is to define the wiring and cabling of an Ethernet in industrial environments It is important to note that standards defining the specifications for connectors already exist The usage of these connectors in industrial Ethernet applications still needs to be standardized Several networking organizations Modbus IDA IAONA PNO ODVA have made recommendations related to the type of copper connectors to use within different industrial environments At the time of this writing these are only recommendations and not standards For light duty industrial environments the market has accepted the use of RJ45 connectors in accordance with the IEC 60603 7 standard Some organizations have proposed the use of protective housings for
465. stem 296 SCADA implementations 295 hub in an Ethernet system 59 humidity range requirements 72 hunting to determine if a SCADA communication path is correct 301 I O scanner response time formulae 329 troubleshooting 356 I O scanning common fault conditions 176 diagnostic word 173 disable 172 enable 172 error handling 172 health bit 173 operation 170 read operations 172 remote device requirements 168 repetition rates 174 response times 177 service selection 158 TCP socket usage 173 when to use 168 write operations 171 I O scanning characteristics 168 IEC 1000 4 standard for electric and electromagnetic interference 76 IEEE 802 3 Ethernet standard 32 in the Transparent Ready model 127 IGMP 136 IGMP snooping 136 immunity standards 76 impedance ISO IEC 11801 performance parameter 512 independent interfaces on an Ethernet network 289 industrial applications for Ethernet 17 industrial Ethernet defined 16 how it differs from commercial Ethernet 17 industrial site backbone 42 industrial site distributor 41 548 31006929 8 2007 Index information management levels in a FactoryCast HMI Web server operation 239 ingress protection requirements degree of protection 74 pollution levels 73 installation measures to combat EMI in Ethernet networks 94 installation standards 32 intermittent connections in an Ethernet system 350 internal clocks for I O scanning repetition rate
466. sting technology 198 31006929 8 2007 Services Overview Publisher and Subscriber Operations The global data operation involves two types of participants with one or more publishers and one or more subscribers A publisher is responsible for putting data on the network The publisher takes a collection of local data and sends it to the distribution group at a rate configured in the publisher device The distribution group is a logic group of subscribing devices possibly spanning across more than one network You can make a subscribing device part of a distribution group by assigning it a unique multicast IP address This IP address is a separate additional IP address from the normal IP address used for Modbus I O scanner Web etc All devices within the distribution group use this unique multicast IP address see p 135 The subscriber receives a copy of all data published to the distribution group selects only the blocks of data that it subscribes to and passes that data to the user application Error handling must be done on the subscriber side because the publisher does not send the data to individual subscribers The publisher puts data on the network it has no control over the subscribers and does not receive feedback when a subscriber receives data The subscriber is responsible for monitoring the time between receiving new data from each publisher If the time between two successive updates of data from an indivi
467. sturbing pair is weaker at the far end due to attenuation Because the FEXT value is related to the attenuation of the cable it is typically measured to obtain the ELFEXT but not reported Equal level far end crosstalk ELFEXT is a mathematical calculation that is obtained by subtracting the attenuation of the disturbing pair from FEXT This pair induces in an adjacent pair The formula is ELFEXT FEXT Attenuation Power sum ELFEXT PSELFEXT is the sum of the values of the individual ELFEXT effects on each pair by the other 3 pairs It is similar to the calculation used for PSNEXT The calculation used to measure ELFEXT removes the impact of attenuation on FEXT 514 31006929 8 2007 Earthing Grounding Procedures DC Loop Resistance Propagation Delay Delay Skew Longitudinal to differential Conversion Loss Balance DC loop resistance is the total resistance through two conductors looped at one end of the link It is usually a function of the conductor diameter and varies only with distance This measurement is sometimes done so that gross misconnections do not add significant resistance to the link Propagation delay is a measure of the time required for a signal to propagate from one end of the circuit to the other Delay is measured in nanoseconds ns It is the principle reason for a length limitation on LAN cabling In many networking applications such as those employing CSMA CD there is a m
468. systems interconnect interconnection A structure for internetworking heterogeneous computers for distributed application processing according to international standards A 7 layer network architecture model of data communication protocols developed by ISO and CCITT Each layer specifies particular network functions such as addressing flow control error control encapsulation and reliable message transfer open shortest path first A link state routing protocol in which every switching node router passes a full map of network connections used to calculate the best next hop from one router to the next packet packet switched network PCMCIA physical address physical control layer physical layer A series of bits containing data and control information formatted for transmission from one node to another It includes a header with a start frame the source and destination addresses control data the message itself and a trailer with error control data called the frame check sequence A network in which data is transmitted in packet units The packets can be routed individually over the best available network connection and reassembled as a complete message at the destination Personal Computer Memory Card International Associates Developers of a standard for a device card to add memory use for a modem fax or use as a portable disk drive An address identifying a single node Layer 1 in the system network archi
469. t gaps and collisions A moderately loaded fast Ethernet shares 25 Mb s of real data in the same situation Collisions increase on both networks as more nodes and or more traffic are added to the shared collision domain Again good planning in segmenting the network and by using intelligent switches aids in reducing congestion and maintaining good performance 56 31006929 8 2007 Planning and Layout Ethernet Broadcast Domains VLANs A broadcast is the transmission of the same message to multiple recipients on the network Any device configured for network broadcast receives that message Broadcasting can be very useful However if the domain created in the network design is too large a broadcast can create such a large amount of traffic that delays result Some types of broadcast data may cause more delays than others but the delays impact the performance of every device on the network Limit the size of the broadcast domain with a router or intelligent switch that controls the delay from excessive broadcasts Using components such as routers to delineate broadcast domains can improve overall performance on a network Routers between multiple LANs form logical broadcast domain boundaries Since routers filter network traffic a router can be configured to forward only specific broadcasts to other domains Using a router for this process may add time but increase the efficiency of transmission A virtual LAN groups de
470. t server applications check that the server other destination device is properly operating on network Check to see if other clients have the same problem to determine if the issue is with an individual client or if it is a system wide problem Note Specific tools are available to perform automatic testing of a cable These tools test for correct cable type selection pin connection etc For details on brands and models see Physical Layout chapter see p 27 31006929 8 2007 349 Troubleshooting Intermittent Connection Troubleshooting Problem category Topic Cause and Actions Physical check cables see note e Check for loose connections especially if there is a dongle with PCMCIA between NIC and RJ45 cable connections e Check cables for defects e Check the patch panel connections and grounding e Check cable integrity with a cable testing device after completing necessary logical checks NIC With wireless connections check the signal strength and refresh the signal or eliminate interference between an end device and a wireless access point Logical check OS applications At DOS prompt use the ping command to check the basic level of network connectivity for replies or timeouts If you encounter trouble while connecting to remote networks type trace route at the DOS prompt to check network routing hops for failing points Scan the OS for virus or memory r
471. tages of switching and routing in a single device Access servers allow users to have dial in and dial out connections p 144 Modems convert analog and digital signals and support connections to the network over voice grade telephone lines They can be built into other network components or purchased separately 31006929 8 2007 65 Planning and Layout WAN Topology Three device options may be used to plug into a router e modems e CSU DSUs e ISDN terminal adapters CSU DSU hardware connects to a router to provide the connection to a digital network such as a T1 line This hardware may connect as an external component or may be built into more advanced network components Service providers often offer CSU DSUs if not they can help you to configure your CSU DSU properly to work with their line configuration An ISDN terminal adapter is modem used to connect ISDN basic rate interface BRI connections to a router These adapters may be separate devices or built into a router The diagram below shows a WAN consisting of a main site connected to several remote sites Remote Plant A Dial up Connection z CSU DSU Modem Remote Plant B EZ Modem A Access S CSU DSU Server ISDN Circuit AA High end Switched B Router e Remote Plant C Sa Main Plant Modem Servi rorida Frame Relay Circui
472. tallation development and maintenance costs e increased data reliability because the data is collected at source e greater availability of data archiving With an internal architecture similar to that of an HMI SCADA system FactoryCast HMI modules manage their own variable database in real time independent of the PLC program This variable database executes various functions including internal processing archiving alarm and email Variables in this real time database are updated by the automation system s data acquisition service This service becomes operational once the following parameters have been set in the FactoryCast HMI software e direct import of PLC variable symbol databases without duplicate entries e definition of the acquisition frequency the period at which this variable is updated Note A FactoryCast HMI application running in a configured Premium FactoryCast HMI module can also access the remote PLC variables in the architecture via a transparent network X Way Uni TE transparent protocols FactoryCast HMI Web services have e a maximum of 1000 I O variables from PLCs per application e a maximum of 100 internal variables per application e a minimum acquisition frequency of 500 ms 31006929 8 2007 239 Services Overview Connections to Relational Databases Database Characteristics Calculation Functions The FactoryCast HMI module can be connected directly to the foll
473. tandards Section 4 Emission standard for industrial environments The following table lists standards and publications that describe the requirements related to electromagnetic compatibility see p 489 The following IEC publications table gives the equivalent European standards documents in brackets below each appropriate publication reference IEC Publications Description General IEC 1000 1 1 1992 Application and interpretation of fundamental differences and terms Environment IEC 1000 2 1 1990 Electromagnetic environment for conducted low frequency LF interference and the transmission of signals over public supply networks IEC 1000 2 2 1990 Compatibility levels for conducted low frequency LF interference and the transmission of signals over low voltage public supply networks IEC 1000 2 3 1992 Radiated phenomena and conducted phenomena at frequencies other than mains frequencies 31006929 8 2007 485 Standards and Considerations IEC 1000 4 Standard IEC Publications Description IEC 1000 2 4 1994 Compatibility levels in industrial installations for conducted low frequency interference IEC 1000 2 5 1995 Classification of electromagnetic environments Limits 552 2 IEC 1000 3 2 Limits for rated harmonic current lt 16 A per 1995 EN 61000 phase emitted by appliances 3 2 1995 552 3 IEC 1000 3 3 Limitation of voltage fluctuations an
474. tecture model Layer 1 the bottom layer of the OSI reference model is implemented by the physical channel It governs hardware connections and byte stream encoding for transmission It is the only layer that involves a physical transfer of information between network nodes The physical layer insulates layer 2 the data link layer from medium dependent physical characteristics such as baseband broadband or fiber optic transmission Layer 1 defines the protocols that govern transmission media and signals 31006929 8 2007 531 Glossary physical media ping point to point port port multiplier PPP PRI print server Any physical means for transferring signals between OSI systems Considered outside the OSI Model and sometimes referred to as Layer 0 or the bottom of the OSI Reference Model packet Internet groper To test the network by trying to reach a destination with an ICMP echo request and waiting for a reply type ping exe at the command line A circuit connecting two nodes only or a configuration requiring a separate physical connection between each pair of nodes The physical connector on a device enabling the connection to be made A concentrator that connects multiple devices to a network point to point protocol A protocol that provides router to router and host to network connections over both synchronous and asynchronous circuits The successor to SLIP primary rate interface Of the two
475. temperature range 71 recommended levels of pollution 73 RJ45 copper connectors 87 shock requirements 69 storage temperature range 71 tensile strength requirements 70 UV exposure requirements 72 vibration requirements 69 linked interfaces on an Ethernet network 289 load limits for Ethernet messages 331 logical check operating system 349 logical connections troubleshooting an Ethernet system 347 31006929 8 2007 549 Index longitudinal to differential conversion loss ISO IEC 11801 performance parameter 515 loop resistance ISO IEC 11801 performance parameter 515 M MAC address 136 machine distributor 42 machines creating equipotential bonding for 98 MBP_MSTR block to monitor Ethernet communications in a Quantum system 299 mechanical ratings for environmental parameters and requirements 30 mechanical requirements crush 70 flexing 70 shock 69 tensile strength 70 vibration 69 mesh topology 48 52 MIB for network management 137 MICE 30 Modbus function codes 182 Modbus client 182 183 limits ina Momentum system 188 limits in a Premium system 186 limits in a Quantum system 185 operations in a Momentum system 188 operations in a Premium system 187 operations in a Quantum system 185 retry times 196 time outs 196 Modbus communication standard 180 Modbus messaging 181 client communication limits 328 client limits in a Momentum system 188 client limits in a Pre
476. tent problems that are difficult to diagnose Earthing also referred to as grounding the equipotential bonding of equipment cabinets buildings and the planning of cable runs within the site are discussed in detail with a focus on measures to be taken for an industrial automation communications system What s in this This section contains the following topics ion Section Topic Page EMC Installation Rules for Ethernet Networks 94 Equipotential Bonding 95 Equipotentially Bonding Your Building 96 Local Equipotential Bonding of Equipment and Machines 98 EMC compatible Ethernet Wiring and Cable Runs 99 Ethernet Copper Cable Types 105 Ethernet Copper Cable Tools 108 How to Make an Ethernet Cable 109 Cabling Administration 111 Cabling Documentation 112 31006929 8 2007 93 Planning and Layout EMC Installation Rules for Ethernet Networks Introduction Installation Measures to Combat EMI in Ethernet Networks Earthing and Equipotential Bonding Defined When properly incorporated into the planning of your network the following methods can help you avoid electromagnetic disturbances and create an EMC compliant environment Protecting the Ethernet network from electromagnetic interference EMI is an issue that involves your complete installation Although it is important to be concerned about EMI immunity throughout your entire system this section describes only methods that apply to your Ethernet netwo
477. tes with the Quantum Premium Micro Momentum Compact Series 7 and S1000 PLC ranges on the following networks Modbus Serial RTU TCP IP IP or X Way addressing Modbus Plus Uni Telway Fipway Ethway ISAway PClway USB 258 31006929 8 2007 Services Overview OFS is compatible with the Nano on a Uni Telway network with these restrictions e read operations only e access to a single word or x bits within 16 consecutive bits The following table outlines OFS 3 1 compatibility with devices in the Schneider Electric SA range and the different networks Network Premium Micro Series 7 Series 1000 Ethway TSXETY110 Ethway TSXETH107 ETH030 TSXETH200 TCP IP TSXETY110 TCP IP TSXETZ410 TSXETY410 TCP IP TSXETZ510 Built in channel TSXETY510 TCP IP Uni Telway Built in channel Built in channel TSX SCM22 TSXFPP20 TSX FPP20 Fipway TSXFPP20 PCMCIA TSXP7455 TSXFPP20 TSXFPP20 ISAway ISA Bus PClway PCI Bus Modbus TSXSCP11 TSXSCM22 JB cards Modbus TSXMBP100 TSXMBP100 Plus USB Built in channel Quantum Momentum Compact TCP IP 140NOE771 171CCC96030 Built in channel 171CCC98030 Modbus Built in channel 171CCC760 Built in channel 171CCC780 Modbus PLus Built in channel Built in channel USB Built in channel 259 Services Overview Definition of Group of Items OFS services are all based on the concept of a group of items
478. teway sends a message onto the destination network that message follows the timeout and retry timings of that network However the requesting device has sent a message to the gateway that is following the timeout and retry times of the source network If the total time for the timeout and retries on the destination network is longer than the timeout of the source network the source network resends the request Duplicate messages are placed in the queue When Modbus TCP IP is the source network there is no application layer retry as long as the gateway acknowledges the TCP packet there is no retry on the source network However you may manually resend the same message If the first message in the queue is sent to a disconnected device that message times out and is retried All other messages in the queue are delayed and possibly timed out by the requesting device If these messages do time out the requesting device may resend the message causing multiple messages in the queue When the initial message is answered by the gateway it is discarded by the requesting device because this message has already been timed out To avoid this situation the timeout for any messages sent from the source network needs to be set greater than timeout x the number of retires on destination network x the maximum number of requests expected in the queue Avoid having this number become too long Set the number of retries on the destination network to a l
479. th Attenuation is the loss of signal strength as it travels along the cable It is measured in decibels dB A low attenuation number is good the lower the attenuation value the stronger the signal Attenuation depends on the cable length and the frequency Attenuation increases as the cable length increases It also increases as the frequency increases and it is further affected by wire gauge Thicker cables have less attenuation than thinner cables Problems with attenuation are usually related to the use of thin cables bad terminations or long cables Attenuation also increases with temperature 512 31006929 8 2007 Earthing Grounding Procedures Pair to pair Near end Crosstalk Loss Near end crosstalk NEXT is the coupling of a signal from one pair the disturbing pair to another pair the disturbed measured at the end where the signal is injected the near end NEXT represents how much of the transmitted signal in the disturbing pair gets electromagnetically coupled in the disturbed pair It is measured in the disturbed pair at the transmitting end NEXT is measured in dB A high NEXT value is good because it indicates high attenuation from one pair to another NEXT varies with the frequency It needs to be measured within a range of frequencies The figure below is an example of NEXT and attenuation values Transmission signal affected by attenuation Transmit Disturbing pair smaller number more cro
480. that has been broken down into smaller units Breaking a packet into smaller units when transmitting over a network medium that cannot support the original size of the packet frame A group of bits sent over a link that contains its own control information such as address and error detection The size and composition of the frame varies by protocol The terms frame and packet tend to used synonymously although in strict OSI terms a frame is made at layer 2 and a packet at layer 3 or above frame relay A protocol using packet switching to connect devices on a WAN framing Dividing data for transmission into groups of bits and adding a header and a check sequence to each group FTP file transfer protocol A TCP IP protocol for file transfer FTP foil twisted pair Cabling with two conductors wound around each other to lessen crosstalk and a foil casing for added protection full duplex The ability of a device or line to transmit data independently and simultaneously in both directions G gateway A combination of hardware and software that interconnects otherwise incompatible networks or networking devices Gateways include packet assembler disassembler pads and protocol converters Gateways operate at layers 5 6 and 7 the session presentation and application layers respectively of the OSI model GMRP GARP multicast registration protocol A system allowing multi cast of data end stations receive data sent to the multicast group
481. the server is not overloaded To do this force the SCADA to open extra TCP sockets and split the requests between the sockets SCADA is slow but PC is fast and there is no delay on SCADA requests in the server device A queue in the SCADA system itself causes this delay This can happen when the SCADA sends only a single request at a time to the server This usually happens in systems for which only a single TCP socket to the server exists The SCADA section see p 274 gives information for opening more sockets or sending more requests down a single socket elsewhere in this document 364 31006929 8 2007 Troubleshooting 4 5 Bridge Troubleshooting Bridge Troubleshooting Problem Category Topic Suggestions Slow response or slow response There are too many devices on the serial line side of the bridge communication socket rejected Most bridges can only implement a limited number of Ethernet sockets failure This number is usually less than the number of devices connected to the serial line side Therefore if one socket is used per serial device the number of available bridge sockets will be inadequate To solve this reduce the number of devices on the serial line or select the Modbus client device that can send requests to multiple serial devices over a single socket For an I O scanner system that scans devices over a bridge either implement the enable disable feature or change to the Mod
482. the SCADA indicates a problem in SCADA communications SCADA responses might be slowed down by either the SCADA system or by a SCADA request queue inside the server Other requests such as PC requests are not held up in this queue e A slow response from the PC indicates an overloaded server so you reduce the load on the server see p 281 Slow response caused by SCADA SCADA is slow but PC test tool is fast check server response time for SCADA requests Examine the response time of a SCADA request on the server with an Ethernet packet capture tool To do this check one of each request type read write digital analog that the SCADA uses When doing this measurement you may see that after you send the request to be measured the server will send back some responses to earlier requests It is important to wait for the response to the specific request you sent before calculating the response time To identify a specific request response pair either the Modbus transaction ID or another unique feature of the request must be used for example the number of requested registers If the observed response time is slow then a queue of SCADA requests in the server can cause a long delay To improve the response e Reduce the number of requests sent to the server see p 281 Start an additional queue for data access and send requests on that path This works because the PC is able to get a fast response showing that
483. the medium independent interface MDI MDI X functionality in their Ethernet ports This functionality allows the auto switching of transmit and receive wire pairs To connect this type of infrastructure device use either straight or crossover cable the device senses and accommodates the TX RX pairs 31006929 8 2007 107 Planning and Layout Ethernet Copper Cable Tools Introduction Cable Stripper Cable Cutter Cable Crimper You need the following three tools to make an Ethernet copper cable e cable stripper e cable cutter e cable crimper For instructions on how to use these tools when making cables see p 109 A cable stripping tool strips away the outer protective wrapping from the cable and uncovers the core conductive material Acable cutting tool cleanly cuts through the diameter of a length of cable separating it into two lengths When selecting a cable cutter choose a tool that is appropriately sized for the diameter of the cable you want to cut A crimper tool is used to secure the jack to the cable end by the use of pressure P 108 31006929 8 2007 Planning and Layout How to Make an Ethernet Cable Before You Start Make sure you have the following equipment available e RJ45 connectors two for each cable plus extras e Ethernet cable For 10Base T STP Ethernet cable CAT 3 or CAT 5 5e or 6 are recommended 100 m or less e For 100Base TX STP Et
484. tic discharges EN 61000 4 2 801 3 IEC 1000 4 3 1995 02 Testing of immunity to radiated radio frequency ENV 50140 1993 electromagnetic fields 801 4 IEC 1000 4 4 1995 01 Testing of immunity to high speed burst EN 61000 4 4 transients 486 31006929 8 2007 Standards and Considerations Automation Equipment standards TIA EIA 568 Standards Test and Measurement Techniques 801 5 IEC 1000 4 5 1995 02 EN 61000 4 5 Testing of immunity to impulse waves pr IEC 1000 4 6 ENV 50141 1993 Immunity to conducted interference induced by radio frequency fields IEC 1000 4 7 1991 07 EN 61000 4 7 1993 03 Guidance on measurement of harmonics and interharmonics and measuring apparatus applicable to power supply systems and devices connected to them IEC 1000 4 8 1993 06 EN 61000 4 8 1993 09 Testing of immunity to mains frequency magnetic fields IEC 1000 4 9 1993 06 EN 61000 4 9 1993 09 Testing of immunity to impulsive magnetic fields IEC 1000 4 10 1993 06 EN 61000 4 10 1993 09 Testing of immunity to damped oscillating magnetic fields IEC 1000 4 11 1994 06 EN 61000 4 11 1994 09 Testing of immunity to voltage dips brief power failures and voltage variations pr IEC 1000 4 12 Testing of immunity to damped oscillating waves Programmable controllers part 2 Equipment requirements and tests
485. ting and optimizing network requests The purpose for these rules is to minimize the number of requests as much as possible Maximum Size of The table that follows specifies the maximum number of data bytes that can be a Request compacted into a single request Any data items accessed in the same request are from the same PLC cycle and so are consistent in size The byte sizes given in the table can be used to calculate the number of items of the same type that can be read or written in a PLC communication request A word takes up 2 bytes a double word 4 bytes and a floating point word 4 bytes Count 8 bits per byte except when you are reading with a PL7 PLC on an XWAY network in which case each byte contains only 4 bits For example on a PL7 PLC running on XIP 248 MB 62 MD 124 MW or 992 M can be read in one request and 244 MB 61 MD 122 MW or 1960 M can be written in 1 request The following table lists the number of data bytes that can be compacted in one Unity Pro device request Communication Medium Read Write XIP 249 235 XIP Built in channel 256 242 TCP IP 1022 1008 PClway 224 210 USB 1022 1008 USB X Way USBX 1020 1006 Fipway 123 109 Uni Telway 241 227 Ethway 249 235 Modbus Plus 250 236 Modbus RTU 249 235 264 31006929 8 2007 Services Overview Use of Groups Optimizing Requests Dividing items into different groups can have an effect on the construc
486. tion contains the following topics ion Section Topic Page Electronic Mail Notification Service 218 Electronic Mail Notification Service Operation 220 Devices that Support Email Notification 222 31006929 8 2007 217 Services Overview Electronic Mail Notification Service Summary The electronic mail notification service allows PLC applications to report conditions monitored by the PLC by running an email client inside an Ethernet communication module The PLC can automatically and dynamically create short electronic mail messages to alert specified users to alarms events production reports maintenance reminders plant status updates other plant information Recipients may be local or remote This service allows you to create predefined email headers including recipients names email addresses and message subject to be used with different email bodies Some devices let you include values dynamically obtained from the latest information in the PLC application or machine state other devices allow only predefined messages Multiple email messages can be created to describe different events or alarms including several system variables This option can be change by an authorized administrator Note Because messages need to be processed through an email system delays may occur between the time the message is sent and the time it is received Therefore this service should be used only for noncr
487. tion flowing through them Potential network overload all devices share the same trunk cable 31006929 8 2007 45 Planning and Layout Ring Topology In a ring topology all devices or network infrastructure components are connected in a loop with no beginning or end Packets travel in a single direction on the ring as they are passed from one device to the next Each device checks a packet for its destination and passes it on to the next device Ring topologies provide redundancy The failure of a single link is handled by routing traffic in the opposite direction A ring may be based on token rotation or random shared access Alternatively it may be a switched network where all the devices access the network at the same time at different speeds Advantages Disadvantages Redundancy the failure of a single link or infrastructure component does not affect the entire network High cost more cabling is needed to complete the ring A ring topology uses software to monitor the network links Network infrastructure components need intelligence to respond to device failures they are more costly than simple bus or star components 46 31006929 8 2007 Planning and Layout Dual Ring Topology When industrial automation systems are used in critical applications where downtime is unacceptable a dual ring topology may be deployed
488. tion of network requests For each device the items are separated into independent sets if necessary However the sets are not determined by the groups themselves but by the Group Min update rate Net Manager XWAY Net Manager Modbus Global Data Group Manager Var Manager Client X The groups do not influence the generation of network requests Declaring items in two different groups with the same update rate generates the same number of requests as declaring items in a single group Requests are generated in batches made up of items belonging to groups with the same period They are not generated within a group Each set of items is optimized individually corresponding to a device and a frequency Optimization algorithms act in two stages e compacting grouping items of the same type with similar or consecutive addresses in tables For writing grouping is performed only if the items are strictly consecutive Obtain a list of elements from the original items to send to the PLC to read or write On Series 7 PLCs compacting is not performed on unitary bits for bit tables it is performed only if the number of bits is a multiple of 8 e concatenating constructing requests by optimizing the possibilities of the protocol Certain protocols let you define access to different types of objects in the same request OFS automatically adjusts the size of requests to the maximum that is admissible Unity devices use both
489. tivar ATV 38 58 variable speed drive Service VW3A58310 1 0 Scanner Modbus Server X Modbus Client Global Data FDR Server FDR Client BootP Client x Xx Time Synchronization E mail Notification Web Embedded Diagnostics FactoryCast Web Server SNMP FTP Server TFTP Server Telnet Server The following table lists the Ethernet services supported by the Power Logic EXG gateways Service EGX200 EGX400 1 0 Scanner Modbus Server Modbus Client Global Data FDR Server FDR Client BootP Client Time Synchronization E mail Notification Web Embedded Diagnostics FactoryCast Web Server SNMP FTP Server 31006929 8 2007 317 Services Overview Service EGX200 EGX400 TFTP Server Telnet Server X X 1 Device receives and sends Modbus messages as a gateway ConneXium The following table lists the Ethernet services supported by the ConneXium NES Cabling Systems NOS managed switches and the CEV gateways Service 499NES17100 499NOS17100 174CEV30020 174CEV20030 174CEV20040 I O Scanner Modbus Server x x x Modbus Client x x x Global Data x2 x2 x E 5 FDR Server E E FDR Client BootP Client X X X X X Time Synchronization g 2 E ma
490. to Receive Response 1 3 4 4 4 4 5 2 4 4 5 7 8 10 3 5 7 6 18 18 22 4 6 8 8 18 19 25 5 6 8 10 19 20 29 6 7 9 12 19 24 35 7 8 17 18 23 28 41 8 8 18 18 26 33 48 9 9 19 21 30 38 55 10 9 19 21 33 43 63 11 10 19 21 36 47 69 12 10 20 21 40 53 76 13 11 21 23 43 58 83 14 13 23 24 47 63 91 15 13 24 25 51 68 99 16 14 24 25 55 74 106 17 14 24 25 59 79 115 31006929 8 2007 439 Modbus Client Performance Modbus Client Response Times Quantum 140 CPU43412A with a 140 NOE77111 Ethernet Communications Module Test Setup The following charts show Modbus client response times where the client request block is triggered in PLC logic by reading data from a Modbus server The graphs represent the number of CPU cycles required for the PLC to complete all triggered Modbus client requests In all cases the PLC is a Quantum 140 CPU43412A with a 140 NOE77111 Ethernet communications module The CPU logic scan times vary Modbus client response times are tracked with respect to six Modbus server response times lt 1ms 10 ms 20 ms 50 ms 70 ms e 100 ms 440 31006929 8 2007 Modbus Client Performance At a CPU Scan Time of 200 ms CPU Cycles 0 5 10 15 20 Communications Completed The table below shows the data points used to generate the graph represented above PLC Scan ms Server Response Time ms 200 lt
491. to Remote Access 0 0 c eee ett 141 Remote Access TypeS 0 0c cece eee eee 142 Network Access Methods 0 0 cece eee e eee 144 PLC Connected to the Internet 00 0 c cece eee 147 Security ISSUCS as 3 ai Sora Viti date he tae iets ote a ees 149 Services Overview 200 e cece e eee eee teens 153 Evaluating System Requirements 00000 cece eee eee eee 154 Common Services at each Level in the Plant 2000 20 eae 155 Company Level Communication 0 0000 c cece eee 156 Inter PLG Level dioii a eect lat een ee tats ale datas oh ete AER ae oe AE 157 Field Level Communications 0 0 0 cece eee ee 157 Communication Service Selection 0 00000 cece eee eee 158 Transparent Ready Support Services and Protocols 0005 161 3 2 3 3 3 4 3 5 3 6 3 7 3 8 3 9 3 10 3 11 VO Scanning Service 0 0 0 0 ce teens 166 I O Scanning Service Description 0 c eee eee 167 I O Scanner Operation 0 0 eee ee 169 Repetition Rates es 3 ne ke eek etd wee Gare dae beeen eae ae bree we 174 Some Common Fault Conditions 0 0 0c eee ee 176 Response TIMES saspe ook Aes a E eai a ae a white die a deere beeen 177 Modbus Messaging 0 00 eee ett 179 Modbus Messaging Service Description 0000 cece eee eee 180 Devices that Support Ethernet Modbus Services 0000 00 184 Modb
492. too frequent a rate you could overload the network with traffic An update rate of every 30 s to 1 min should be sufficient to provide data without generating unnecessary traffic 138 31006929 8 2007 Planning and Layout Routing Summary Routers Routing Process Routing Tables Routing is a method of finding paths to move messages from one network to another network The Internet uses a process in which each node router looks at a packet s header information calculates the next hop on the route to the destination and delivers the packet to the next node which repeats the process The process occurs at Layer 3 A router is a device that connects two or more networks at a gateway and forwards packets along the network It has an Ethernet card or another interface for each network The message is looked at by the sending device If the destination is local the message is sent directly to the end device If the destination is remote not on the same network the message is sent to the default gateway the local router This router uses its own information about connected networks to pass the message either to the final network if it is directly connected or to the next router closer to the final destination A routing table contains a record of the best routes possible to reach a number of given network destinations A routing table includes information needed for determining that route the destinatio
493. trial processes demanding 24x7 attention the ability to administer network devices from a remote location is increasingly desirable Remote access is useful for e OEMs whose machines may be installed anywhere in the world e end users who may not maintain local support staff e system integrators looking to add more value to their offer e systems requiring remote data gathering For example an alarm for tank overflow is paged to an operator The operator logs in checks the status of the tank determines that it is safe to halt pumps and pauses the process until morning so that the situation can be investigated and corrected Another example is that of an OEM who ships a machine to a customer in another country The customer chooses to use a different type of sensor than the one the specified by the OEM After start up the system does not work as planned With remote access the OEM is able to log into the plant modify the program and get the customer s machine running without a costly time consuming on site visit Three methods of remote access are commonly used each via a different protocol e direct access to a PLC via dial up e remote control of a PC via dial up e remote access to the complete network To determine the most suitable type of connection you need to establish a list of functions that your remote connection must provide Common features include e data gathering e remote troubleshooting e programming softwa
494. ts It does this by disabling the line in the I O scanner causing the data transfer to stop but enabling the Premium to communicate When the I O scanner data is required the line can be re enabled again The problem with this solution is that there is no coordination between the SCADA and the Quantum on which system is attempting to use the socket This can lead to communication errors or retries if both devices attempt to read data at the same time 336 31006929 8 2007 Services Overview Gateway Response Times Summary The response time for a gateway system can be calculated in one of two ways e Gateway with or without protocol conversion actual calculation including response time of devices on the destination network and queues inside the gateway e Gateway using shared memory For simple response time just the time to read the internal memory can be used For a full system response for data in a destination device through the gateway and to a device on the source network the reading of data into the gateway often based on a timer must be included The simplest way to calculate response time is to consider a single message to read data The following actions must occur e A device on the source network must send out a request to read the data the delay is dependant on the requesting device e The gateway receives the request the delay from the time the requesting device sends the request to the time the gatewa
495. ts communicating with the device As a result the I O scanner starts to communicate with each device when each is ready rather than waiting for all devices to be ready For global data service the standby NOE leaves the global data group and the new primary joins the group and starts publishing The time required for this is dependent on the implementation of multicast filtering see p 136 and the number of devices in the group global data start up times All other services force clients to disconnect either by reset or time out Services are restarted on both the primary and standby Ethernet communications modules As a result services are unavailable for a short amount of time but overall system operation is not affected For example the NTP service restarts but the CPU clock remains accurate for the time required to restart the service A Telnet session is disconnected and you must reconnect The most recent versions of distributed I O on Ethernet TCP IP have a function for maintaining the status of the outputs when there is a break in communications such as a hot standby changeover Devices controlled by distributed I O continue to operate during the changeover TCP Socket In all cases the TCP source sockets used on the new module and the old module Numbers should be different Different sockets prevent confusion between the old and new connections to the remote device 31006929 8 2007 303 Services Overvi
496. ts that interconnect devices and extend the network length In general hubs are plug and play devices that require no configuration Hubs are transparent to other devices and are essentially repeaters that extend network segments They receive information through any of their ports and pass along that information to all of their other ports A limited number of hubs can be cascaded to extend the length of the network Devices interconnected by hubs are in the same collision domain they are in the same network segment where information packets can collide Thus hub devices decrease network efficiency Switches are active devices used to interconnect devices and to extend network length Unlike hubs switches receive information through any of their ports and forward that information only to the port where the target device of the incoming information is connected An unlimited number of switches can be cascaded to extend the length of the network Switches are transparent for the devices in the network They offer many features to manage traffic and to provide security see p 137 Switches break up collision domains so that devices interconnected by switches are in different collision domains 31006929 8 2007 59 Planning and Layout Types of Switches Transceivers Bridges Routers Gateways Layer 3 Routing Switches There are two types of switching cut through and store and forward e Cut through switch
497. ty against non malicious activity however can be implemented by personnel who do not possess this level of specialized training Security Policy Your security policy defines the information and services to be accessed how they can be accessed and who will be given access to them Defining a security policy rather than just beginning to implement one without a plan is more likely to help you cover all areas Planning also makes it easy to remember what security to apply when you add to the network Passwords Passwords should be changed monthly Do not choose simple user names and passwords if you are trying to prevent malicious access Default passwords on all devices should be changed or disabled since default settings are often easy to find in user manuals Physical Access Preventing physical access to a network is crucial in implementing security against malicious attacks It is very easy to get SNMP or telnet passwords when you have physical access to the network Therefore preventing physical access to the network infrastructure is crucial in keeping control of the network layout The time spent organizing network traffic in an efficient way can be negated by users who make the network inoperable or prevent device communications 31006929 8 2007 149 Planning and Layout Firewalls Modbus Filtering and Firewalls Advanced Firewalls Setting Up a Firewall Access Control Lists A firewall is a device or pr
498. ueue 309 response times 337 using shared memory 308 with application protocol conversion 307 without application protocol conversion 306 gateway delay 337 gateway socket 310 gateway timeout 310 gigabit Ethernet 55 global data application synchronization 202 device support 201 limits 200 response times 203 service selection 158 standards 198 using multicast technology 202 when to use the service 201 global data service error handling 199 GMRP 136 graphical data editor in a FactoryCast Web server 233 ground connection for cable shielding 504 procedure 502 31006929 8 2007 547 Index ground connections recommendations 500 ground loops 508 group management over an Ethernet system 136 group membership in an IP multicast system 136 group of items in an OPC factory server operation 260 H health bit for I O scanning 173 heavy industrial environment crush requirements 70 degree of ingress protection 75 flexing requirements 70 humidity range 72 M12 circular connectors 89 operating temperature range 71 recommended levels of pollution 73 shock requirements 69 storage temperature range 71 tensile strength requirements 70 UV exposure requirements 72 vibration requirements 69 HMI client server model 276 standalone model 275 troubleshooting 364 HMI tag database in a FactoryCast HMI Web server operation 239 horizontal cabling 36 hot standby in a communication centric sy
499. uld be lost to critical devices 54 31006929 8 2007 Planning and Layout LAN Technologies and Network Design Summary Ethernet Advantages and Standards Fast Ethernet and Gigabit Ethernet Ethernet Frames Packets Avoiding disruptions in data transfer is an issue of paramount importance to an industrial network planner perhaps even more of a priority than throughput speed of information transfer Discussed below are issues of network design such as congestion collision management and broadcasting that can influence the smooth fast transfer of information along the network Suggestions are given for proper network design that can minimize the potential for disruptions Whereas several technologies can be used to build an IP network Ethernet has emerged as the preferred technology for both office and industrial environments Among the LAN technologies Ethernet has become the most popular because it offers the benefits of speed cost and ease of installation It can support virtually all popular network protocols and has gained wide acceptance in the computer marketplace as an excellent networking technology for most network environments The IEEE defines rules for configuring an Ethernet network and specifying how elements in an Ethernet network interact with one another in IEEE Standard 802 3 Adherence to IEEE 802 3 enables your network equipment and network protocols to communicate efficiently
500. ules the server service enables it to respond to requests from other PLCs SCADA HMls and other devices Devices that do not need to respond to data transfer requests should not need to implement a server service 31006929 8 2007 183 Services Overview Devices that Support Ethernet Modbus Services Device Modbus Client Modbus Server Unity Pro Quantum 140CPU65150 140CPU65160 140NOE77101 140NOE77111 140NWM10000 Unity Pro Premium TSXP571634M TSXP572634M TSXP573634M TSXP574634M TSXP575634M TSXETY4103 TSXETY110WS TSXETY5103 TSXWMY100 TSX Micro TSXETZ410 TSXETZ510 Momentum 171CCC96020 171CCC96030 171CCC98020 171CCC98030 X XK KK OK X OK OK X X X X X OK X Xx X Xx KI Xx 171ENT11001 171ENT11002 X X X X X X X X X X X X X X X X X X X x x Xx Twido 499TWD01100 a Advantys STB STBNIP2212 x Altivar ATV38 58 VW3A58310 x Power Logic Gateways Bridges EGX200 EGX400 ConneXium Cabling systems 174CEV30020 174CEV20030 174CEV20040 1 Device receives and sends Modbus messages as a gateway 184 31006929 8 2007 Services Overview Modbus Client Operations in Quantum Systems Limits Quantum Modbus Client Operations With Concept or Proworx programming softwar
501. umber of repeaters hubs within a network segment Check for loops in the Ethernet network that can be caused by e aConnexXium ring without a redundancy manager configured e incorrect spanning tree setups e a loop created by incorrect cabling among switches Logical Os Scan the OS for virus or memory resource issues applications Check applications for multiple instances of overloaded system resources Establish whether the problem is system wide by examining other network devices network hardware Check hub switch or router if applicable for e network traffic congestion e a possible network broadcast storm e large bandwidth usage large downloads streaming audio video etc A network traffic analyzer sniffer can help Note Specific tools are available to perform automatic testing of a cable These tools test for correct cable type selection pin connection etc For details on brands and models see Physical Layout chapter see p 27 31006929 8 2007 351 Troubleshooting Remote Access Troubleshooting Problem category Topic Cause and actions Physical check cables Check for proper physical cable connections from the end device to the wall patch panel hub or switch Also check for cable defects lacerations and causes of interference like electrical noise Replace questionable patch cables with new ones RuJ 11 for dial up With dial up connect
502. until all pending messages are sent before it can be processed This can create slow system response times The best response times are achieved when the queue is never empty and never longer than 1 or 2 messages request pending response response to client all requests move up in the queue a new request is placed at the end of the queue anhoOnN 31006929 8 2007 309 Services Overview Gateway Sockets Gateway Timeouts A gateway enables a large number of devices on one network to communicate with a large number of devices on another network When a large number of devices connects to an Ethernet network gateway a large number of TCP sockets must be opened For low cost gateways the number of sockets is limited by the low processing power and low memory of the components chosen Once the number of sockets is exceeded no additional devices can connect to the gateway Problems can be caused when e the requesting devices choose communications services that require a TCP socket for every device they communicate with e services hold a socket open after communications have finished Examples of these are the I O scanner service and the Modbus client service on older devices To reduce the number of sockets held open on a gateway use the enable disable function in the I O scanner or Modbus client requests When a ga
503. urements is at version 2 0 and CPU with a the TSXETY5103 Ethernet communications module is at version 3 1 TSXETY5103 Module 450 400 350 4 300 4 250 4 200 4 32 devices Time ms 150 4 100 4 1 16 devices 0 T T T T 0 50 100 150 200 PLC Scan Time ms The bottom curve shows that the response times for 1 to 8 devices are within 1 ms of each other The response times for 16 devices increase by 2 to 3 ms For 32 devices response times are approximately 12 to 16 ms longer The table below shows the data points used to generate the graph represented above Number of Devices to Scan Time from Scanned Device Input to Scanned Device Output ms TSXP575634 v2 0 ETY 10 ms 20 ms 50 ms 100 ms 200 ms 5103 v3 1 Scan Scan Scan Scan Scan 1 device 24 44 104 204 405 8 devices 25 45 105 205 406 16 devices 28 47 107 206 408 32 devices 40 60 118 218 417 31006929 8 2007 377 I O Scanner Performance TSXP57304M The TSXP57304M CPU used for the following measurements is at version 2 0 and CPU witha the TSXETY5103 Ethernet communications module is at version 3 1 TSXETY5103 Module 450 400 350 4 300 4 250 4 200 4 Time ms 150 4 100 50 4 0 t T T T 0 50 100 150 200 PLC Scan Time ms The bottom curve shows that the response times for 1 to 8 devices are within 2 ms of ea
504. us Client Operations in Quantum Systems 00000 eee 185 Modbus Client Operations in Premium Systems 000000 186 Modbus Client Operations in Momentum Systems 020000 188 Modbus Server Operations in Quantum Systems 000 0 eee 189 Modbus Server Operations in Premium Systems 0 0 005 192 Modbus Server Operations in Momentum Systems 0 00505 194 Modbus Servers and Socket Limits 2 0 0 0 e eee eee 195 Modbus Messaging Retry Times and Time outs 20 000 196 Global Data Service ser se e a 0 00 c cette 197 Global Data Considerations saaana cette 202 Faulty Device Replacement 0 0 c cece eee 204 Devices that Support the FDR Services 0000 c cece eee eee 207 Time Synchronization e a ete tees 208 Time Synchronization Service 0 0 0 cect tee 209 Time Synchronization Service Operation 0 00 cece eee eee 211 Time Synchronization Applications 0 0 0 0 cece ee 212 Schneider Devices Implementing Time Synchronization Service 216 Electronic Mail Notification Service 1 0 0 cee 217 Electronic Mail Notification Service Operation 0 00 eee eee 220 Devices that Support Email Notification 0 0 0 0 cece eee 222 Standard Web Server 00 0 cece ttt 223 Web Server Services 0 0 0 0 c eect tee tees 224 Web Server Operation 0 0 c cece eet eee
505. used because this is the scan time of the Premium PLC a Premium PLC is able to answer requests within one CPU scan The Quantum PLC triggers a read request which is immediately sent to the Premium PLC The Premium answers this within one CPU scan time 70 ms The Quantum receives this response and brings it into the PLC application the next time the request block is processed causing a delay of 1 CPU scan 50 ms The total time from when the block is triggered to when the response is available is 120 ms 334 31006929 8 2007 Services Overview Problem 5 Problem What is the response time for a Quantum PLC with a scan time of 50 ms to read 10 4x registers from each of 25 remote power meters that each has a response time of 100 ms Quantum PLC with 25 power meters having a single block of 10 registers in each power meter mim I e HH Answer The Quantum can send only 16 messaging requests at a time from a single NOE module There are two methods for evaluating using a graph from the appendix or performing system evaluation If 25 requests are triggered 16 are sent immediately The meters answer after 100 ms and the responses are taken into the PLC application the next time the request block is processed This causes a delay of 1 CPU scan 50 ms After 150 ms the PLC has the answers to 16 requests inside the PLC application The remaining 9 blocks are sent The meters answer 100
506. ust moisture and vibration possible 31006929 8 2007 17 Transparent Ready The Transparent Ready Strategy Office Ethernet Industrial Ethernet Minimum pulling requirements Risk of mechanical damage or problems with chemicals Required grounding and bonding of industrial equipment and cabling Layout Limited floor size in vertical Large manufacturing areas in only buildings one floor Star topology Star bus and daisy chain topologies may be used In accordance with office Self healing ring and redundant self standards healing ring to maximize up time Performance High network availability High network availability typically with reliable connections 24X7 with redundancy Large data packets Low bandwidth usage always recommended no higher than 40 at all times Acceptable level of predictability Small data packets Predictability is essential There are other areas of differentiation as well such as the Ethernet services required Transparent Ready offers a three stage strategy 1 Expose industrial control information via open or de facto standards OPC and embedded Web server products open Schneider Automation devices to several systems that can access information and knowledge buried in the devices Standard Web server technology allows any qualified personnel in the enterprise to interact with the automation system 2 Create interfaces and
507. ves the message 9 The Modbus server responds to the request 10 The response travels across the network and a network delay occurs 11 The Momentum receives the response 12 At the end of the next CPU scan the response is read into the Momentum and the socket is closed 13 The next time the Modbus client block is reached in the code the response and any new data is made available to the application 188 31006929 8 2007 Services Overview Modbus Server Operations in Quantum Systems Quantum Implementation Quantum Modbus Server Operation A Modbus server is implemented in either an NOE Ethernet communications module or an Ethernet port embedded in the Quantum PLC The data to be accessed by the Modbus server is held in the PLC CPU memory The interface between the NOE module or the embedded port and the CPU defines the Modbus server operation The Modbus server for Quantum systems operates as follows Sequence Event 1 A Modbus client establishes a TCP socket to the NOE module or the embedded Ethernet port The Modbus client sends a request along the TCP socket The NOE module or the embedded Ethernet port receives the request and may acknowledge it The request is placed in the queue inside the module to be passed to the CPU The CPU lets the NOE module embedded Ethernet port access its memory at the end of the next CPU scan In the case of the NOE module the NOE p
508. vice A device that implements the Modbus server service can respond to requests from any Modbus client The Modbus server service allows a device to make all its internal and I O data available to remote devices for both reading and control The Modbus protocol is a collection of function codes where each code defines a specific action for the server to perform The ability of a device to perform read and write functions is determined by the Modbus function codes that are implemented by the server The Modbus protocol is based on five memory areas inside the device Memory Area Description Ox or M Memory bits or output bits 1x or l Input bits 182 31006929 8 2007 Services Overview When to Use the Client When to Use the Server Memory Area Description 3x or IW Input words 4x or MW Memory words or output words 6x Extended memory area In addition to the function codes for reading and writing data within these areas there are codes for statistics programming device identification and exception responses The Modbus server can make data available based on the following limits e Read 125 words or registers e Write 100 words or registers A Modbus client should be used when data needs to be exchanged between two devices at irregular or infrequent intervals such as when an event occurs The client allows a request to be triggered by the application code i
509. vices that may be in different physical locations into a virtual network sharing resources servers and other devices among a workgroup Using a VLAN to segment traffic can increase network performance by reducing the size of collision domains and of traffic loads It offers a flexible and less expensive way to modify groups in an environment that could change The grouping also adds consistency to addressing and protocols an advantage to the administrator and needs less local server resources A VLAN adds security safeguards as well There are several ways of grouping devices into a VLAN Port based VLANS are end stations that are grouped by ports on a switch If they are plugged into certain end ports they belong to the same group VLAN ports can be configured using intelligent switches that support VLAN configurations Another type of VLAN configuration is protocol VLAN PVLAN in which the switch automatically looks at all ports and groups end stations by protocol End stations can also be grouped by IP network address Once an IP address is assigned to an end station it is placed in a specific VLAN 31006929 8 2007 57 Planning and Layout Wireless IP End stations can also be grouped on the basis of their IP addresses After the IP address is assigned to an end station it is placed into a specific VLAN VLANs can be implemented on layer 3 switches see p 60 to create multiple broadcast domains simi
510. way Performance Serial Devices with 50 ms Response Time Time ms 9000 4 8000 4 7000 4 6000 4 5000 4 4000 4 3000 2000 4 1000 4 20 40 60 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 50 Timeout EGX200 Time to Complete All Requests 1000 ms 1 Retry Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request 8 Requests 16 Requests Bridge Time Registers 1 2200 83 2644 163333 3150 83 2194 17 2590 836667 3044 17 187 5 16 2200 83 2994 163333 3900 83 2194 17 2765 836667 3419 17 187 5 32 2200 83 3367 496667 4700 83 2194 17 2952 50333 3819 17 187 5 64 2200 83 4114 163333 6300 83 2194 17 3325 836667 4619 17 187 5 100 2200 83 4954 163333 8100 83 2194 17 3745 83667 5519 17 187 5 31006929 8 2007 453 Gateway Performance Serial Devices with 100 ms Response Time Time ms 0 T T T T T 6 T 0 20 40 60 80 100 Number of Registers The table below shows the data points used to generate the graph represented above Device Serial Server Response Time 100 Timeout EGX200 Time to Complete All Requests 1000 ms 1 Retry Baud Rate 9600 19200 Number of 1 Request 8 Requests 16 Requests 1 Request
511. when the groups are polled continually or as required how the polling of groups is linked The groups of variables should be set up so they are polled at a rate no faster than that which the field device can answer To calculate this rate consult the system performance evaluation section see p 319 Remember to take into account all other devices including other SCADA systems that are communicating with the field device When creating groups try to group tags so that the polling of the groups can be turned on and off The variables are polled only when they are required You may code this behavior or use an automatic feature of the SCADA system In either case the alarm variables need to be placed into one group and trending variables into one or more groups separate from the display variables The group containing the display variables needs to be polled only when the tags are active on a screen 278 31006929 8 2007 Services Overview When SCADA systems use an OPC server to read data from a field device each I O server may create separate groups even though each I O server is polling the same variables The SCADA system may try to add remove variables from the groups on the OPC server This process is inefficient because of time delays The preferred alternative is for the SCADA system to create a larger number of groups with fewer variables in each group and enable disable the groups or variables within the groups However
512. while it is transmitting it aborts transmission and retries after a random period of time The channel service unit data service unit prevents electrical interference while it transmits receives signals to from the WAN T Technique for examining incoming packets whereby an Ethernet switch looks only at the first few bytes of a packet before forwarding or filtering it This process is faster than looking at the whole packet but it also allows some bad packets to be forwarded data link data link layer datagram DCF DCOM DHCP A logical connection between two nodes on the same circuit Layer 2 of the seven layer OSI reference model for communication between computers on networks This layer defines protocols for data packets and how they are transmitted to and from each network device It is a medium independent link level communications facility on top of the physical layer and is divided into two sub layers medium access control MAC and logical link control LLC A means of sending data in which parts of the message are sent in a random order and the recipient machine reassembles the parts in the correct order A system of precision time signals sent from a transmitter near Frankfurt Germany used for time synchronization distributed component object model An extension of COM Component Object Model mode DCOM mode is used for two remote machines to communicate with one another It replaces inter process commun
513. wledges the synchronize message from the client and opens the socket from the server back to the client 31006929 8 2007 537 Glossary synchronous The client application that calls a read or write service is blocked from further services requests for the time it takes to obtain a result from the original request T T connector tap connector TCP IP Telnet terminal server terminator TFTP thick wire thin wire time out A T shaped device with two female connectors and one male BNC connector Physical hardware that allows connection of a device or new section of cable to a trunk cable transmission control protocol Internet protocol A set of protocols developed by the U S Defense Department s Advanced Research Projects Agency ARPA during the early 1970s Its intent was to develop ways to connect different kinds of networks and computers TCP IP does not have the functionality that OSI provides TCP IP is a transport and Internet working protocol i e the de facto networking standard It is commonly used over X 25 and Ethernet wiring and is viewed as one of the few protocols available that is able to offer a true migration path towards OSI TCP IP is able to operate in most environments TCP IP operates at Layers Three and Four of the OSI model Network and Transport respectively TCP and IP are the standard network protocols in UNIX environments They are almost always implemented and used together
514. ximum length is 2 km It has been classified as the best type of cable to use between buildings multiprotocol label switching Integrates information on Layer 2 into Layer 3 thereby allowing routing of traffic around system problems A function block used for programming A new standard connector for optical cables maximum transmission unit The largest size packet a network can transmit measured in bytes The size is set by the network administrator and can be different for each network Larger packets are divided before they are sent but this slows transmission speed A repeater either stand alone or connected to standard Ethernet cable that interconnects up to 8 thin wire Ethernet segments A message sent out to multiple devices on the network by a host A special form of broadcast where copies of the packet are delivered to only a subset of all possible destinations name server Software that runs on network hosts charged with translating text based names into numeric IP addresses 31006929 8 2007 529 Glossary Nano network network address Small range PLC platform from Schneider An interconnected system of computers that can communicate with each other and share files data and resources Every node on a network has at least one address associated with it including at least a fixed hardware address assigned by the device s manufacturer Most nodes also have protocol specific addresses assigned by
515. y a shielded jacket Connectors are expected to be specially designed proprietary components TIA and ISO are cooperating on this category The two most widely installed categories are CAT 3 for 10Base T and CAT 5 for 100Base T While the two cables may look identical CAT 3 is tested to a lower set of specifications and can cause transmission errors if pushed to faster speeds CAT 3 cabling is near end crosstalk certified for only a 16 MHz signal CAT 5 cable must pass a 100 MHz test CAT 5E has recently replaced CAT 5 as the prevalent standard There are two main types of twisted pair shielded twisted pair STP and unshielded twisted pair UTP Usually STP and UTP cables have two pairs of cables 4 conductors Screened twisted pair ScTP is four pair 100 Q UTP with a single foil or braided screen surrounding all four pairs to minimize EMI radiation and susceptibility to outside noise ScTP is also called foil twisted pair FTP or screened UTP SUTP It can be thought of as a shielded version of the CAT 3 4 and 5 UTP cables It may be used in Ethernet applications in the same manner as the equivalent category of UTP cabling Note Transparent Ready s industrial Ethernet must use shielded CAT 5E cables UTP and STP cables comes in two forms solid and stranded Solid refers to the fact that each internal conductor is made up of a single solid wire Stranded means that each connection comprises multipl
516. y receives the request is dependent on the source network For an Ethernet network the delay is normally 0 05 ms For a Modbus Plus network the delay may be up to one token rotation time the time which it takes the token message packet to rotate around the ring and return to the sending device Refer to the Modbus Plus User s Guide for more information e The gateway passes the request to the destination network this is the gateway delay see p 377 If there is a queue this time can be significant Gateway delay is common if the two networks connected by the gateway have very different response times e The request is received by the destination device the delay is based on the ability of the destination network to transfer the message For Modbus Plus this is one token rotation time For serial networks it depends on the speed of the network e The request is processed by the destination device this is dependent on the actual device e An answer is sent back to the gateway the delay is based on the ability of the destination network to transfer the message For Modbus Plus it is one token rotation time for serial networks it depends on the speed of the network e The gateway passes the response back to the source network this is the gateway delay see p 377 If there is a queue this time can be significant This is common if the two networks connected by the gateway have very different response times e The response is received
517. ycles 70 ms 25 cycles 100 ms 35 cycles 410 31006929 8 2007 Modbus Client Performance at a CPU Scan Time of 10 ms bos 170 4 160 4 j 150 oA 140 4 et 130 4 120 4 110 4 100 4 90 4 80 4 70 4 60 4 50 4 40 4 30 4 20 1014 CPU Cycles 10 ms 0 5 10 15 20 25 30 35 40 45 50 55 60 65 Communications Completed A sampling of results in the chart follows Number of Requests Server Response Time CPU Cycles Needed To Complete 1 lt 1 10 ms 3 cycles 20 ms 5 cycles 50 70 ms 7 cycles 100 ms 8 cycles 3 lt 1 ms 5 cycles 10 ms 4 cycles 20 ms 6 cycles 50 ms 10 cycles 70 ms 12 cycles 100 ms 13 cycles 10 lt 1 ms 6 cycles 10 ms 7 cycles 20 ms 18 cycles 70 100 ms 22 ms 31006929 8 2007 411 Modbus Client Performance Number of Requests Server Response Time CPU Cycles Needed To Complete 16 10 ms 8 cycles 20 ms 18 cycles 50 ms 22 cycles 70 ms 27 cycles 100 ms 22 cycles 21 lt 1 ms 8 cycles 10 20 ms 19 cycles 50 ms 22 cycles 70 ms 27 cycles 100 ms 31 cycles 33 lt 1 ms 11 cycles 10 ms 19 cycles 20 ms 24 cycles 50 ms 25 cycles 70 ms 44 cycles 100 ms 54 cycles 39 lt 1 ms 4 cycles 100 ms 17 cycles 45 lt 1 ms 14 cycles 10 ms 21 cycles 50 ms 58 cycles
518. your installation documentation see p 112 31006929 8 2007 113 Planning and Layout 2 6 Verification of a Transparent Ready Industrial Ethernet At a Glance Overview What s in this Section This section focuses on the process of verifying your cable installation based on the requirements of the ISO IEC 11801 standard Verification is a critical step in making your installation conform to all applicable standards You should test the complete cable installation as well as the individual components of the network You can choose to test each section of the network as it is installed recommended and or plan a final verification stage when you can test everything Because testing is the only way to verify that your installation conforms to local and international standards Schneider Electric recommends that you become familiar with the recommen dations in this section At this time there is no international standard for planning and installing an industrial Ethernet network However there are recommendations from industrial Ethernet organizations and on going activities that have resulted in the creation of a draft for such a standard Plans are to publish this standard as ISO IEC 24702 by the end of 2006 This section contains the following topics Topic Page Transparent Ready Industrial Ethernet Verification Recommendations 115 Permanent Links 116 Channels 118 Testing a C
519. ystem 296 SCADA implementations 295 queue for messaging through a gateway 309 R rack viewer in a Web server operation 227 RAS systems 144 read operations for I O scanning 172 recycle power when troubleshooting an Ethernet system 343 redundancy and network communication services 288 redundancy levels ina SCADA system 292 redundant system for Quantum 297 fully implemented for Quantum 298 limitations in a Quantum system 297 552 31006929 8 2007 Index relational database connection to a FactoryCast HMI Web server 240 remote access to an Ethernet system 141 via dial up 142 remote access server layout 144 remote access to an Ethernet system troubleshooting 352 remote access VPN 146 remote configuration using a Web server 225 remote data transfer services for plant data 163 remote device I O scanning requirements 168 repeater in an Ethernet system 59 response time for a gateway 337 Premium I O scanning performance 178 Quantum I O scanning performance 177 response times for global data 203 Modbus server service summary 324 return loss ISO IEC 11801 performance parameter 512 ring topology 46 RJ45 connector color code for wires 80 pinouts 80 RJ45 copper connectors 87 RM12 circular connectors 89 router in an Ethernet system 60 in an Ethernet WAN 65 routing using IP addressing 139 routing cables between buildings 104 routing cables between cabinets 104 running cables

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