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1785-6.5.2, 1785-KE Data Highway Plus Communication Interface

1. Mounting the 1785 KE Module Making Connections to the 1785 KE Powering Up the 1785 KE Module Connecting Your RS 232 C Device to the 1785 KE Chapter The RS 232 C PORT Connector Electrical Characteristics of the RS 232 C Character Transmission Cabling for Your RS 232 C Direct Connection to a Connection to Another Communication Module Connection to Modem Choosing a Modem for Point to Point Full Duplex Applications Using the 1785 KE in an Auto Answer Application len leo le Ino In loo IN leo m len le 1 sees c I le ko loo ko leo lo la le m Table of Contents Choosing a Modem for Multidrop Half Duplex Applications Communicating Through the 1785 KE Module Chapter Application 1 Connecting a Computer to Data Highway Plus Computer to PLC 5 PLC 2 Normal Unprotected PLC 2 Normal Unprotected Read PLC 3 Normal Unprotected Write
2. a 10 0 07 032 011 010 044 04 027 4 Sl je 1 18 6 16 Mess 10 0 07 027 5 07 030 031 031 030 6 1 1 1 1 1 1 00 0 10 10 032 033 033 032 H gt lee en jee 00 00 10 10 040 040 8 TON 15 1 0 PRE 999 041 041 9 1 TON 15 1 0 PRE 999 042 042 10 1 TON 15 1 0 PRE 999 043 043 11 l TON 15 1 0 PRE 999 040 041 042 043 050 12 G G 6 G 044 045 046 047 050 13 6 6 6 6 PUT Rungs 8 through 11 are timer values to write to and then read from the PLC 5 Chapter 5 Communicating Through the 1785 KE Module The following table summarizes the purpose of each rung in the example For more information on 1771 KGM master programming refer to the 1771 KGM User s Manual publication 1771 6 5 39 Rung 1 10 11 12 13 What It Does communication one header rung the timeout preset code the third GET statement may need to be increased depending on your RS 232 C link characteristics configuration rung defines the nodes to be polled by the 1771
3. Figure 3 6 Setting Switch Assembly SW 3 DOWN UP ON OFF HBBBH LJ LJ RK LN Side View Local Remote Addressing RS 232 Link Baud Rate See Table Below Data Highway Plus Baud Rate Set both switches to DOWN ON position in You use switches 1 and 2 to set the Data Highway Plus communication rate Both switches must be DOWN for 57 6 Kbit communication rate You use switches 3 4 and 5 to set the communication rate for the RS 232 C link between your device and the 1785 KE figure 3 6 Use the following table to set these switches To Set this Rate Set These Switches in Bits Per Second 3 4 5 110 UP OFF UP OFF UP OFF 300 DWN ON UP OFF UP OFF 600 UP OFF DWN ON UP OFF 1200 DWN ON DWN ON UP OFF 2400 UP OFF UP OFF DWN ON 4800 DWN ON UP OFF DWN ON 9600 UP OFF DWN ON DWN ON 19200 DWN ON DWN ON DWN ON Chapter 3 Installing the 1785 KE You use switch 6 of SW 3 to set local remote operation Use the table below as a guide to setting this switch If You are Using the 1785 KE Set Switch 6 to to Connect computer or other intelligent RS 232 C local mode DOWN ON device to a Data Highway Plus network Data Highway Plus node such as aPLC 5 remote mode UP OFF as a slave on a multidrop link using a modem fig 2 5 two Data Highway Plus networks over a remote mode UP OFF point to point modem link fig 2 4 Communications to a 1785 KE Series A is the same
4. carries serialized data It is an output from the module is serialized data input to the module RXD and RXDRET are isolated from the rest of the circuitry on the modules is a request from the module to the modem to prepare to transmit RTS is always ON with full duplex protocol It typically turns the data carrier on With half duplex protocol RTS is turned ON when the module has a message to transmit Otherwise RTS is OFF is a signal from the modem to the module that indicates the carrier is stable and the modem is ready to transmit The module will not transmit until CTS is on If CTS is turned off during transmission the module will stop transmitting until CTS is restored is a signal from the 1785 KE module to the modem to indicate that the module is operational and ready for communication The module will continually assert DTR except during an auto answer application such as the one discussed in Chapter 4 In auto answer applications DTR is a signal from the module to the modem to connect to the phone line i e pick up the phone The module will assert DTR all the time except during the phone hangup sequence Modems built to American standards will not respond to DTR until the phone rings Some European modems will always pick up the phone whether it is ringing or not The 1785 KE module will not work with these types of European modems is a signal from the modem to the 1785 KE module to indicate that the mod
5. A done bit or a successful reply should cause the next command to be initiated If an error bit or a reply with non zero status is returned you must decide the appropriate action based on your application 2 7 Chapter 2 Overview ofthe 1785 KE and Data Highway Plus Applications Three typical applications of the 1785 KE are discussed in this manual connecting a computer or other intelligent device to Data Highway Plus via an RS 232 C point to point link local mode full or half duplex protocol option connecting two Data Highway Plus networks together over a point to point modem link remote mode full duplex protocol option a connecting a Data Highway Plus node such as a PLC 5 as a slave on a multidrop link with a modem remote mode half duplex slave protocol option These are discussed in more detail later in Chapter 5 Communicating through the 1785 KE Module A short discussion of each application follows Figure 2 3 shows an example of using a 1785 KE to attach a computer or other intelligent RS 232 C device to Data Highway Plus You attach the computer to Data Highway Plus using a point to point RS 232 C link Figure 2 3 shows the following three options using s a short 50 feet or less RS 232 C link a the AB longline RS 232 C option a point to point modem link Refer to Chapter 4 for more information on these RS 232 C options Figure 2 3 Point to Links to a Data Highway Plus Network
6. E Major Section File Element Sub Element A command of this format can be accepted by the PLC 5 because the address has only 4 levels Communicating From Computer to a PLC 5 Appendix D Interprocessor Addressing Make sure that a the PLC 5 file you will communicate with is created and large enough to handle the command a you specify the PLC 5 address in a message instruction as shown above If you were to enter a PLC 5 address in normal PLC 3 address format N1 0 the 1775 KA would format a six level address If the PLC 5 receives a six level address it will be unable to read it and will return an EITOT The following example shows a PLC 3 message instruction with a PLC 5 address Start Bit 032 MSG Message Type 1 CTL FB200 0000 0 te Channel E2 5 1 15 H040 E0 1000 N1 0 10 ER Destination Source remote local 17057 A computer can communicate with a PLC 5 on Data Highway Plus using the 1785 KE module The table below gives a summary of PLC 5 data table areas based on the type of commands your computer sends The extent to which your computer can access PLC 5 data table areas depends on the addressing capabilities of the computer s software Refer to the Data Highway Data Highway Plus Protocol and Command Set Reference Manual publication 1770 6 5 16 for information necessary to create a Data Highway of Data Highway Plus software driver for your computer A
7. Figure 6 1 The LED Indicators Receiving Ready Active Error 17055 Chapter 6 1785 KE Diagnostic Tools The following table contains the meaning of each LED on the front panel of the 1785 KE This LED Lights XMTG when the 1785 KE module is passing the token transmitting a command or transmitting a reply message on Data Highway Plus RCVG when the module is receiving a command or reply message from another node on Data Highway Plus RDY when the module has a message stored in its transmit buffer and it is waiting to acquire the token so it can transmit ACTV stays lit when the cable between the COMPUTER RS 232 C connector and the interfacing RS 232 C device is properly connected This light will appear to flicker whenever characters are being transmitted across the RS 232 C link If this light goes off check the cable and connectors for possible problems Note This ACTV LED is hardware not software driven ERROR At power up this light flashes if the power up tests integrity checks of internal memory timers and firmware fail After power up this light flashes for approximately half a second every time the module transmits or receives a DLE NAK protocol sequence on the RS 232 C link If this light flickers frequently or stays on the RS 232 C link might need better isolation or noise immunity flashes at approximately 1 Hz when a duplicate node two nodes with the same node number is detected on th
8. NU Allen Bradley 1785 KE Data Highway Plus Communication Interface Module Cat No 1785 KE User Manual Table of Contents Using This Chapter Objectives Purpose of This Manual Who Should Read This Series B Enhancements Frequently Used Terms Precautionary Notes Related Products Related publications Overview of the 1785 KE and Data Highway Plus Chapter Objectives What is the 1785 KE Module What is Data Highway Plus The Physical Link Layer Delivery Order of Commands 5 Installing the 1785 KE Chapter Setting the Communication Option Switches Switch Assembly SW 1 RS 232 C Link Features Switch Assembly SW 2 Data Highway Plus Node Address Switch Assembly SW 3 Communication Rates and Local Remote Option Switch Assembly SW 4
9. a mounting the module connecting the module to the Data Highway Plus link powering up your module Refer to Chapter 4 for information on how to connect your RS 232 C device to the 1785 KE module Read the first two chapters of this manual carefully before attempting to install the 1785 KE Important The Series B version of the 1785 KE module uses different communication option switches has a different front cover and has different Data Highway Plus connectors than the Series A version This chapter describes the Series B version Information on setting the Series A communication option switches and making connections to the Series is included in Appendix C for reference The 1785 KE module has 4 switch assemblies figure 3 1 that enables you to select various communication options The switch assemblies and their corresponding options are Select this For this Switch Assembly Communication Option SW 1 RS 232 C link features SW 2 Node number SW 3 Data Highway Plus and RS 232 C link communication rates Local remote option SW 4 Reserved Chapter 3 Installing the 1785 KE Figure 3 1 Location of the Switch Assemblies on the 1785 KE Module FULL A FULL FULL MT ERROR CHECK Fees even we ves ves wo IGNORE EXECUTE PASS THRU STATION NUMBER OCTAL DIGIT 0 STATION NUMBER OCTAL OIGIT 1 STATION NUMBER OCTAL DIGIT 2 RESERVED mm s RESERVED A Em RATE 68002 RATE LOC AEM ADOR
10. Modem 1785 KE Module Modem Link Asynchronous link 50 cable ft max 1785 KE Module 1785 KE Module Allen Bradley longline T RS 232 C link 7000 cable ft 1771 KG Module PLC 2 30 2 8 Chapter 2 Overview of the 1785 KE and Data Highway Plus You can use either full duplex or half duplex for the RS 232 C link Figure 2 4 shows an example of using a 1785 KE series B to connect two Data Highway Plus networks over a point to point modem link You must set the 1785 KE for full duplex protocol in this application Figure 2 4 Communication Between Two Remote Data Highway Plus Networks emt er Belden 9463 17037 2 9 Chapter 2 Overview ofthe 1785 KE and Data Highway Plus Figure 2 5 shows an example of using the 1785 KE series B to connect a Data Highway Plus node such as a PLC 5 to a multidrop network The PLC 5 acts as a slave on the multidrop link You must set the 1785 KE for half duplex protocol and use modems Figure 2 5 Multidrop Networking Using the 1785 KE Series B PLC 2 1771 KGM PLC 5 PLC 2 PLC 5 1785 KE 1771 KG 1785 KE 17038 Chapter Objectives Setting the Communication Option Switches Chapter 3 Installing the 1785 KE This chapter explains how to install the 1785 KE module There are four parts to installation setting the communication option switches
11. Press a key for desired function or lt ESC gt or RETURN to exit monitor RUN no forces decimal data decimal addr PLC 5 Addr 11 SIZE IN TOGGLE ELEMNTS BIT F3 F9 5 17 Chapter 5 Communicating Through the 1785 KE Module Program Verification Example 3 Slave to Slave Communication To verify that the example programs above are executing properly follow these steps 1 Look at the PLC 5 file contents of integer file 7 by typing DISPLAY MONITOR N7 0 2 Change any value in word locations 0 through 7 in this file 3 These values in word locations 10 through 17 should be the same as the values in word locations 0 through 7 Important These PLC 5 slave to PLC 2 master example is for testing only Toggling the continuous bit to ON generates high network traffic which in most cases is not necessary In this example we send a message from the PLC 5 with Data Highway Plus address 013 octal to the PLC 5 at Data Highway Plus address 011 octal In this case the PLC 5 sends the command to a local destination address 023 a remote destination address 011 The command remains in the 1785 KE address 023 buffer until the master polls address 013 The 1785 KE recognizes address 013 as an address on the Data Highway Plus link and sends the command to the master The master sees that the destination address 011 is not its own address and immediately retransmits the message onto the multidrop link The 1785 KE
12. Word Range Write PLC 3 Normal Unprotected Read Word Range Read Application 2 Communicating Between Two Data Highway Plus Networks PLC 5 Write Commands PLC 5 Read Commands Program Verification Application 3 Multidrop Applications With the 1785 KE Series Example 1 Master to Slave Communication Example 2 Slave to Master Communication PLC 2 Unprotected Write PLC 2 Unprotected Read Program Verification Example 3 Slave to Slave Communication PLC 2 Unprotected Write Head Program Polling More Than One PLC 5 on a Data Highway Plus Using the Multidrop Expansion 0 1785 KE Diagnostic Tools Chapter Using the LED Indicators The 1785 KE Diagnostic Counters What is a Diagnostic Counter How to Read Diagnostic Counters 1785 KE Data Highway Plus Diagnostic Counters Specifications Definiti
13. the command can only have a four level address In this example the address is in logical binary form The following paragraphs show line monitor examples for this command 1 Computer sends command to the 1785 KE DLE STX DST SRC CMD STS TNS TNS FNC PO TT TT ADDRESS IDLE 10 02 29 20 OF O0 4 01 00 00 00 04 00 OF 00 OA OF 00 22114433 66 55 88 7710 03 DI 2 1785 responds to computer DLE 10 06 3 1785 KE sends command to the PLC 5 The 1785 KE sends the command onto Data Highway Plus and the PLC 5 node at address 51 octal 4 PLC 5 sends the reply to the 1785 KE The PLC 5 receives the command executes the command formats a reply and sends the reply back to the 1785 KE 5 1785 KE sends the PLC 5 reply back to the computer DLE STX DST SRC CMD STS TNS TNS DLE BCC 10 02 20 29 4F 00 46 01 10 03 21 6 Computer responds to the 1785 KE DLE 10 D6 5 5 Chapter 5 Communicating Through the 1785 KE Module PLC 3 Normal Unprotected Read Word Range Read This example reads the 4 words 8 bytes of data that you sent with the PLC 3 Word Range Write command in the previous example When you send a PLC 3 command to a PLC 5 the command can only have a four level address In this example the address is in logical ASCII form The following paragraphs show line monitor examples for this command 1 Computer s
14. 1 EN Processor Type PLC 2 Destination Data Table Address N7 0 control bit N10 20 11 ERROR CODE 0 Press a key for desired function or lt ESC gt or RETURN to exit monitor RUN no forces decimal data decimal addr PLC 5 Addr 11 SIZE IN TOGGLE ELEMNTS BIT F3 F9 5 19 Chapter 5 Communicating Through the 1785 KE Module 5 20 Read Command This example reads the eight words that were written to the remote PLC 5 address 011 octal in the last example The instruction stores the data in the local PLC 5 address 013 octal integer file 7 word locations 10 through 17 Program a message MSG instruction with the parameters shown below Also you must set up the message instruction for continuous mode by toggling bit N30 20 11 to ON MESSAGE INSTRUCTION DATA MONITOR FOR CONTROL BLOCK N10 20 Read Write WRITE ignore if timed out PLC 5 Data Table Address N7 0 to be retried Size in Elements 8 awaiting execution Local Remote REMOTE continuous Remote Station 011 error Link ID 00 message done Remote Link Type DATA HIGHWAY message transmitting Local Node Address 23 message enabled Processor Type PLC 5 Destination Data Table Address N7 0 control bit addr ERROR CODE 0 Press a key for desired function or lt ESC gt or RETURN to exit monitor RUN no forces decimal data decimal addr PLC 5 SIZE IN TOGGLE ELEMNTS BIT F3 F9 0TO 0 NR 0 EW 1CO 0 ER 0 DN 15 N10 20 11 Ad
15. 1785 KE s RS 232 asynchronous link has a selectable communication rate from 110 bits per second to 19 200 bits per second It uses a selectable protocol of half duplex master slave polled or full duplex peer to peer unpolled You can select the half duplex protocol for a multidrop or point to point communication link You can select the full duplex protocol only for a point to point communication link 2 5 Chapter 2 Overview ofthe 1785 KE and Data Highway Plus 2 6 Full Duplex Protocol The full duplex protocol conforms closely to ANSI X3 28 combining features of subcategories D1 data transparency and F1 two way simultaneous transmission with embedded responses You can use full duplex protocol for a point to point link that allows two way simultaneous transmission It is relatively difficult to implement because it requires you to use interrupts and multi tasking programming techniques It is intended for high performance applications where you need to get the highest possible throughput from the available communication medium Half Duplex Protocol Half duplex protocol serves as an alternate to full duplex protocol Half duplex protocol is similar to full duplex in most respects Two major differences are a Half duplex protocol provides for polling of slave stations a Half duplex protocol does not allow embedded responses Half duplex protocol is used for a link between one master and one or more slaves You
16. 5 and the 1785 KE will hear the message and pass it through Therefore you can use the same network addressing for PLC5 1785 KE slave nodes as for PLC 2 1771 KG slave nodes Figure 5 3 below will be used for the examples of this section Note that a PLC 2 1771 KG 012 is shown as a slave in the figure to illustrate the fact that the 1785 KE Series B allows both PLC 5 s and PLC 2 s to be addressed identically on the multidrop Figure 5 3 Using the 1785 KE Series B on a Multidrop Un PLC 2 1771 KGM 014 Master PLC 5 011 PLC 2 PLC 5 013 1785 KE 021 1771 KG 012 1785 KE 023 Remote Mode Remote Mode Slaves 17050 Chapter 5 Communicating Through the 1785 KE Module Note When using the 1785 KE in this application you must set each slave 1785 KE to Remote Mode by correctly setting the Local Remote Option switch see Chapter 3 for details You may wish to refer to Appendix D Interprocessor Addressing for more background information on addressing PLC 5 s from PLC 2 s Setting the 1785 KE s Node Address When used in a RS 232 multidrop application the 1785 KE has each of the following a a Data Highway Plus address on the Data Highway Plus link aslave node address on the master slave multidrop network A single 1785 KE node address used on both links is selected by setting the appropriate switches on Switch Assembly SW 2 see Chapter 3 for details on setting option switches The valid range of
17. Addr 10 SIZE IN TOGGLE ELEMNTS BIT F3 F9 5 9 Chapter 5 Communicating Through the 1785 KE Module Program Verification To verify that the example programs above are executing properly follow these steps 1 Look at the local PLC 5 node 10 octal file contents of integer file 7 by typing DISPLAY MONITOR N7 0 2 Change any value in word locations 0 through 7 in this file 3 The values appearing in word locations 10 through 17 should be the same as the values in word locations 0 through 7 Important These PLC 5 to PLC 5 examples are for testing only Toggling the continuous bit to ON generates high network traffic which in most cases is not necessary Application 3 Multidrop Applications With the 1785_KE Series B Chapter 5 Communicating Through the 1785 KE Module This section focuses on examples that use a 1771 KGM PLC 2 master which interfaces over an RS 232 C multidrop to PLC 5s used as slaves If you are writing your own master driver or need more information on Allen Bradley half duplex protocol refer to the Data Highway Data Highway Plus Protocol and Command Set Reference Manual publication 1770 6 5 16 The examples in this section discuss message transfers as they occur with a PLC 5 using a 1785 KE Series B The 1785 KE acts as a slave on the multidrop and listens for messages addressed to a PLC 5 on its Data Highway Plus link Thus the master can send a message addressed directly to a PLC
18. Bradley Bulletin 1771 I O rack follow these steps 1 Perform an orderly power down of the I O rack and its controlling PLC processor WARNING Remove system power before removing or installing your module in the 1771 I O chassis Failure to observe this warning could result in a damage to module circuitry undesired operation and possible injury to personnel 2 Set the keying bands on the I O rack slot The 1785 KE is keyed to guard against installation in the wrong slot in your rack Prior to installing your module in the rack you may insert optional keying bands provided with your 17711 0 rack on the backplane If you elect to use keying bands two are required Insert the first between keying positions 6 and 8 Insert the second between keying positions 12 and 14 3 Slide the 1785 KE module into one of the slots in the I O rack Snap down the latch on the top of the module slot to secure the module in the I O rack Making Connections to the 1785 KE Chapter 3 Installing the 1785 KE The 1785 KE module has 3 connectors on its front edge figure 3 8 Figure 3 8 The Connectors on the 1785 KE Error DATA HIGHWAY PLUS 17045 Chapter 3 Installing the 1785 KE Connecting the 1785 KE to another Data Highway Plus Station Connecting the 1785 KE to another Data Highway Plus Station using a 15 pin connector Connecting the 1785 KE to a 1770 SC station connector To make con
19. Characteristics of the RS 232 C Port For information on how to construct a longline cable for connection to a a 1771 KG module refer to figure 4 3 a 1773 KA or 1775 K A module refer to figure 4 4 To construct the cable use a male connector at each end Use Belden 8723 or equivalent cable available from Allen Bradley under cat no 1778 CR Connect the cable shield at one end only Chapter 4 Connecting Your RS 232 C Device to the 1785 KE Figure 4 3 Connection to a 1771 KG Module User supplied Cable Belden 8723 7000 ft max RS 232 C PORT RS 232 C connector of cat no 1778 CR PORT connector 1785 KE module of 1771 KG module 15 pin Male Connect the shield 15 pin Male Connector at one end only Connector SHLD HR DEUS SHLD Txp 2 rxo crs 5 User supplied Cable 5 Jets Belden 8723 DSR gee 7000 ft max omg c3 DSR er User supplied male connectors 15235 Figure 4 4 Connection to a 1773 KA or 1775 KA Module User supplied Cable Belden 8723 7000 RS 232 C PORT RS 232 C PORT connector of connector of cat no 1778 CR 1773 KA or 1775 KA 1785 KE module module 15 pin Male Connect the shield 25 pin Male Connector at one end only Connector Es User supplied Cable 5 GTS DSR Belden 8723 DSR Eip 7000 ft max qi Ne User supplied male connectors 15236 Chapter 4 Connecting Your RS 232 C Device to the 1785 KE Connection to a Modem To connect th
20. E RS 222 C 15230 Appendix Using a Series A 1785 KE Module You use the top connector labeled PEER COMM INTEC to connect the Series 1785 KE to Data Highway Plus Plug the 15 pin connector of your Data Highway Plus dropline into this connector For details on how to construct the dropline refer to the Data Highway Cable Assembly and Installation Manual publication 1770 6 2 1 You can use the center connector labeled PEER COMM to connect your 1784 T50 terminal to Data Highway Plus You must use a cable with the pinouts shown in figure C 8 Figure C 8 Pinouts for Connecting the 1784 T50 to the Series A 1785 KE User supplied Cable Belden 9463 10 ft max 15 pin Female 15 pin Female Connector Connector Data Blue Blue Second Highway PEER COMM Plus Shid Shid INTFC Interface Module connector of Connector Clear Clear 1785 KE module of T50 x User supplied female connectors 15231 You use the bottom connector labeled RS 232 C PORT to connect an intelligent RS 232 C compatible device to the 1785 KE Series A module Refer to Chapter 4 for guidelines on how to connect RS 232 C devices to the 1785 KE Appendix Addressing How to Address a PLC 5 From a PLC 2 Appendix D Interprocessor Addressing This Appendix discusses the following a How to address a PLC 5 from a PLC 2 a How to address a PLC 5 from a PLC 3 Communicating from a computer to a PLC 5 The PLC 2 does not understand
21. KE on the multidrop This allows you to expand the total number of 1785 KE and PLC 5 addresses on the multidrop beyond the 00 77 octal limitation of DH The figure shows that all of the 1785 KE s have address 21 octal on their respective DH networks The PLC s have addresses of 11 and 12 on their DH networks By setting Digit 0 you change the address as seen by nodes on the multidrop as follows Value of Octal Address on DH Digit 0 0 1785 KE 21 PLC 5 11 PLC 5 12 1 1785 KE 21 PLC 5 11 PLC 5 12 2 1785 KE 21 PLC 5 11 PLC 5 12 3 1785 KE 21 PLC 5 11 PLC 5 12 Address on Multidrop 1785 KE 021 PLC 5 011 PLC 5 012 1785 KE 121 PLC 5 111 PLC 5 112 1785 KE 221 PLC 5 211 PLC 5 212 1785 KE 321 PLC 5 311 PLC 5 312 Chapter Objectives Using the LED Indicators Chapter 6 1785 KE Diagnostic Tools In this chapter we provide a descriptions of the LED indicators on the front panel of the 1785 KE a alist of 1785 KE diagnostic counters and a description of what they contain For information on error codes and and the diagnostic indicators of other Data Highway Plus and Data Highway modules refer to the Data Highway Data Highway Plus Protocol and Command Set Reference Manual publication 1770 6 5 16 There are 5 LED indicators on the front panel of the 1785 KE module figure 6 1 These indicators can help you in diagnosing problems with the module s installation and operation
22. RESERVED 17039 Important The 1785 KE Series B uses the convention DOWN ON Binary and UP OFF Binary 1 Switch Assembly SW 1 RS 232 C Link Features Chapter 3 Installing the 1785 KE Figure 3 2 shows the 1785 KE Series B set for full duplex a BCC error checking a even parity a embedded responses enabled detect and ignore duplicate messages ignore handshaking a execute diagnostic commands Figure 3 2 The Switches on Switch Assembly SW 1 11 2 34 5 6 DOWN UP ON OFF Side View Diagnostic Commands Handshaking Signals Duplicate Messages 17104 The following table shows you how to set switches 1 2 and 3 for the module options you require If You Want to Select Protocol as full duplex full duplex full duplex full duplex full duplex half duplex full duplex half duplex With Error Check as BCC BCC BCC BCC BCC BCC CRC CRC With Parity as none even none even none even none none With Set these Embedded SW 1 Switches Responses 1 2 3 no UP UP UP OFF OFF OFF no DWN UP UP ON OFF OFF yes UP DWN UP OFF ON OFF yes DWN DWN UP ON ON OFF no UP UP DWN OFF OFF ON no DWN UP DWN OFF ON ON yes UP DWN DWN OFF ON ON no DWN DWN DWN ON ON ON 3 3 Chapter 3 Installing the 1785 KE 3 4 Switch 4 determines whether or not the RS 23
23. SR5 Industrial Terminal System 1784 T50 PLC 5 Family Programmable Controllers Series 1785 Chapter 1 Using This Manual Related pu blications For more information on the 1785 KE and the Data Highway Plus network refer to the following documents Publication Publication Number Data Highway Plus Overview Product Data 1785 2 6 Data Highway Data Highway Plus Protocol and 1770 6 5 16 Command Set User s Manual Data Highway Cable Assembly and Installation Manual 1770 6 2 1 The publications in the table above are available from Allen Bradley Contact your local Allen Bradley sales office for more information 1 5 Chapter Objectives What is the 1785 KE Module Chapter 2 Overview of the 1785 KE and Data Highway Plus In this chapter we give you an overview of the 1785 KE module and how it interfaces with a Data Highway Plus network The 1785 KE module is a communication interface that links an intelligent RS 232 C asynchronous device to an Allen Bradley Data Highway Plus network The 1785 KE gives you a choice of full duplex unpolled or half duplex polled protocol on its asynchronous link Figure 2 1 shows the 1785 KE module s hardware features diagnostic indicators connector for the Data Highway Plus a connector for the T50 Industrial Terminal connector for an RS 232 C device Chapter 2 Overview ofthe 1785 KE and Data Highway Plus Figure 2 1 1785 KE Communication Interface Module 1
24. STS TNS TNS DLE BCC 10 02 20 29 48 00 44 01 10 03 2 6 Computer responds to the 1785 KE DLE 10 06 5 3 Chapter 5 Communicating Through the 1785 KE Module PLC 2 Normal Unprotected Read This example reads the 4 words 8 bytes of data that you sent with the PLC 2 Normal Unprotected Write command in the previous example The following paragraphs show line monitor examples for this command 1 Computer sends command to the 1785 KE DLE STX DST SRC CMD STS TNS TNS ADR ADR SIZE DLE ETX BCC 10 02 29 20 01 00 45 01 28 00 08 10 03 40 2 1785 KE responds to computer DLE 10 06 3 1785 KE sends command to the PLC 5 The 1785 KE sends the command onto Data Highway Plus and the PLC 5 node at address 51 octal 4 PLC 5 sends the reply to the 1785 KE The PLC 5 receives the command executes the command formats a reply and sends the reply back to the 1785 KE 5 1785 KE sends the PLC 5 reply back to the computer DLE STX DST SRC CMD STS TNS DATA DLE ETX BCC 10 02 20 29 41 00 45 01 22 11 44 33 66 55 88 77 10 03 cc 6 Computer responds to the 1785 KE DLE 10 06 5 4 Chapter 5 Communicating Through the 1785 KE Module PLC 3 Normal Unprotected Write Word Range Write This example writes 4 words 8 bytes of data to the PLC 5 address 51 octal integer file 10 word locations 15 through 18 When you send a PLC 3 command to a PLC 5
25. a Request to Send RTS sent from the Allen Bradley module to the modem to indicate the module has a message to send and wants a carrier to be established Clear to Send CTS sent from the modem to the Allen Bradley module to indicate that the carrier is established and that the module can send its message a Data Carrier Detect DCD sent from the modem to Allen Bradley module to indicate that a carrier has been detected and that a message is on the way The module uses this signal to enable its receiver Chapter 4 Connecting Your RS 232 C Device to the 1785 KE Figure 4 6 A Typical Packet Transmission Using RTS CTS and DCD Transmitting Tb Ts Tc Module NER E E Dos RTS I ee I OIM ceu DCD Receiving Module Ro yea ee ope RTS OTS me Dede nn en TD is the transmitted data RD is the received data Tb is the point at which the module has a packet buffered and ready to send Ts is the point at which the packet is sent is the point at which the packet transmission is completed 17047 Chapter 4 Connecting Your RS 232 C Device to the 1785 KE The modem you use to interface to an Allen Bradley RS 232 C communication module using half duplex protocol must be capable of supporting standard RS 232 C handshaking described in this section and in Appendix B supporting the baud rate of your module operating on a mu
26. at address 021 recognizes address 011 and passes the command through to the PLC 5 at that address The PLC 5 at address 011 then executes the command generates a reply and sends it to the 1785 KE at address 021 The 1785 KE buffers the message and awaits a poll for address 011 from the master The master then forwards the reply to the PLC 5 at address 013 Both 1785 KE modules are transparent to the master Chapter 5 Communicating Through the 1785 KE Module The following examples show the T50 message instructions necessary to send PLC 5 Read and Write commands from the PLC 5 address 013 octal to the PLC 5 address 011 octal through the 1785 KE modules PLC 2 Unprotected Write This example writes eight words from the local PLC 5 address 013 octal integer file 7 word locations 0 through 7 to the remote PLC 5 address 011 octal integer file 7 word locations 0 through 7 Program a message MSG instruction with the parameters shown below Also you must set up the message instruction for continuous mode be toggling bit N30 0 11 to ON MESSAGE INSTRUCTION DATA MONITOR FOR CONTROL BLOCK N10 20 Read Write WRITE ignore if timed out 0 TO PLC 5 Data Table Address N7 0 to be retried 0 NR Size in Elements 8 awaiting execution 0 EW Local Remote REMOTE continuous 1 CO Remote Station 011 error OER Link ID 00 message done 0 DN Remote Link Type DATA HIGHWAY message transmitting 1ST Local Node Address 23 message enabled
27. destination PLC 5 the same way that you would specify the address of another PLC 2 Appendix D Interprocessor Addressing The PLC 5 s address is specified in the command rung of the PLC 2 s command code specifications Start Command Bit Code 032 040 ozr AAA BBB CCC G G IG 10 00 PLC 5 Address Command Type Priority Indicator Used for Data Highway Only 17056 AAA beginning word addresses in octal of the remote node processor for read write operation BBB beginning word address in octal of the local node processor for read write operation CCC ending word address in octal of the local node processor for read write operation Appendix D Interprocessor Addressing Addressing a PLC 5 From a PLC 3 D 4 When sending a command to a PLC 5 from a PLC 3 use the following guidelines to program the message instruction The PLC 3 has six levels of addressing while the PLC 5 has only four levels Therefore if a PLC 5 received a full PLC 3 six level address it would return an error code The following table summarizes the addressing levels of the PLC 3 and PLC 5 Address Level PLC 3 Family PLC 5 Family 1 Major Section Major Section 8 data table 0 data table 2 Context File Number must be 1 15 3 Section Element 4 File Sub Element 5 Structure 6 Word To communicate from the PLC 3 to the PLC 5 you must enter the PLC 5 address in the following format
28. must use modems for this type of link unless there is only one slave The 1785 KE module has slave mode capability only You must provide the master function through a computer or the 1771 KGM module Half duplex protocol provides a lower effective utilization of resources compared to full duplex but it is easier to implement You should use half duplex protocol if a you are using multidrop modems to connect multiple slave stations to a single master computer a you are using moderns that have only half duplex capability a you are willing to sacrifice data throughput in exchange for ease of implementation Delivery Order of Commands Chapter 2 Overview of the 1785 KE and Data Highway Plus If any node on a Data Highway Plus network initiates multiple commands for example the initiating node sets multiple bits at any time the order in which those commands get executed at the remote node cannot be guaranteed The initiating node the network and the receiving node execute commands based on network conditions including but not limited to nodes buffering commands a retries due to noise on the network If your application requires that commands be delivered in a specific order your logic must control the initiation of one command at a time on the network and verify delivery before initiating additional commands This verification is completed by a adone bit or an error bit in a PLC areply message in a computer
29. slave addresses on the multidrop network is 001 376 octal 010 077 and 110 376 octal when a 1771 KGM is used as the master The valid range of addresses on Data Highway Plus is 00 77 octal Figure 5 4 below shows Switch Assembly SW 2 Figure 5 4 Octal Octal Octal Digit 0 Digit 1 Digit 2 KEY DOWN ON UP _ 1 Data Highway Plus Node Address OFF 2 Lower Two Digits of Multidrop Address Side View Multidrop Address Expansion Digit n Example 1 Master to Slave Communication Chapter 5 Communicating Through the 1785 KE Module Note from the figure that three octal digits are available Octal Digit 0 Octal Digit 1 and Octal Digit 2 Use Octal Digits 1 and 2 to set the 1785 KE s Data Highway Plus address from 00 77 These digits also set the lower two digits of the 1785 KE s address on the multidrop network Octal Digit 0 is an multidrop address expansion digit It sets the most significant highest digit of the 1785 KE multidrop address If your multidrop network only requires addresses 000 077 octal you can set this digit to 00 switch position DOWN DOWN If you need to use addresses higher than 000 077 you will need to set this digit to 1 2 or 3 See Using the Multidrop Address Expansion Digit later in this chapter for more information on setting this digit In this example we send a message from the master 1771 KGM PLC 2 at multidrop address 014 octal through the 1785 KE at address 021 octal to th
30. the file structure of the PLC 5 When a PLC 2 sends a message to a PLC 5 the data is either read from or written to a default file in the PLC 5 This default file is the file number that corresponds to the decimal equivalent of the PLC 2 s octal node address For example a PLC 2 with a node address of 012 octal will read data from and write data to file number 10 012 octal 2 10 decimal in each of the PLC 5s on Data Highway Plus The file type of this file is not pre defined but the file must look like a PLC 2 data table to the PLC 2 The following table shows the octal addresses their decimal equivalents and the PLC 5 reserved files The first 9 files 0 8 are reserved for the data type listed Appendix D Interprocessor Addressing Octal 000 001 002 003 004 005 006 007 010 011 to 376 Make sure that Decimal Equivalent 7 8 9 to 255 a PLC 5 may have a file number up to 999 PLC 5 Reserved File File Type output file input file status file bit file timer file counter file control file integer file floating point user defined files a if you use a communications module with a node address of 000 to 010 octal to communicate with a PLC 5 using PLC 2 commands the module must be able to properly communicate to the corresponding file type listed in the previous table a the file in the PLC 5 is created and is large enough to handle the command you specify the address of the
31. 1 and Digit 2 Octal Digit 0 Octal Digit 0 Switches 1 and 2 should be set to 0 DWN DWN Octal Digits 1 and 2 Data Highway Plus Node Address Octal Digits 1 and 2 are used to set a Data Highway Plus node address for the 1785 KE module The node address is an encoded 2 digit octal number that identifies the 1785 KE module as a unique node on Data Highway Plus Valid Data Highway Plus addresses for the 1785 KE module are 00 to 77 octal Octal Digit 1 switches 3 4 5 is used to set the most significant octal digit 0 7 of the Data Highway Plus node address Octal Digit 2 switches 6 7 8 is used to set the least significant octal digit 0 7 of the Data Highway Plus node address 3 5 Chapter 3 Installing the 1785 KE Figure 3 4 shows you how to set the Data Highway Plus node address with switch assembly SW 2 Figure 3 4 Setting the Data Highway Plus Node Address with Switch Assembly SW 2 Octal Octal Octal Digit1 Digit EN HBHHHBEH SLA Side View Data Highway Plus Node Address See Chart below Set both switches to DOWN ON position Octal Digit 1 most significant Octal Digit 2 least significant To set Set switches 3 5 To set Set switches 6 8 Octal Digit Octal Digit 1 to 2 to No 3 No 4 No 5 No 6 No 7 No 8 0 DWN DWN DWN 0 DWN DWN DWN ON ON ON ON ON ON 1 DWN DWN UP 1 DWN DWN UP ON ON OFF ON ON OFF 2 DWN UP DWN 2 DWN UP DWN ON OFF
32. 2 C port of the 1785 KE module can detect duplicate messages transmitted to it If You Want the Module to Set Switch 4 detect and ignore duplicate messages DOWN ON accept all messages regardless of UP OFF duplication Switch 5 determines whether the RS 232 C port on the 1785 KE module uses and recognizes the following handshaking signals a data set ready DSR request to send RTS a clear to send CTS a data carrier detect DCD a data terminal ready DTR If You Want the Port to Set Switch 5 use handshaking signals DOWN ON ignore handshaking signals UP OFF Important If you select half duplex the 1785 KE uses handshaking signals even if switch 5 is set UP To set diagnostic commands you use switch 6 on SW 1 Use the table below to set switch 6 If you want your module to Set switch 6 execute diagnostic commands DOWN ON pass through diagnostic commands UP OFF Switch Assembly SW 2 Data Highway Plus Node Address Chapter 3 Installing the 1785 KE Switch assembly SW 2 is for setting the Data Highway Plus node address of the 1785 KE figure 3 3 Figure 3 3 Setting Switch Assembly SW 2 Octal Octal Octal DigitO Digit 1 Digit 2 LIT I ues ON 0 OFF HBBBBHBB 1 Side View Data Highway Plus Node Address See Chart below Set both switches to DOWN ON position 17105 As seen in the figure SW 2 represents 3 octal digits Octal Digit 0 Digit
33. 4 you want Set switches to set Switch Assembly SW 3 SW 4 123 O2 ZO MD 15226 For example to set the node address to 37 octal you would set switch assemblies SW 3 and SW 4 as shown below To set To this Set these switches assembly number 1 2 3 SW 3 3 OFF ON ON SW 4 7 ON ON ON Appendix Using a Series A 1785 KE Module Switch Assembly SW 5 Network Link Communication Rate Switch assembly SW 5 lets you select the communication rate for the Data Highway Plus port on the Series A module Figure C 5 shows the switches on SW 5 Figure C 5 The Switches on Switch Assembly SW 5 012 N 0 Both switches ON for F 57 600 bits per second 15227 Important You must set both switches ON for SW 5 This is the setting for a communication rate of 57 600 bits per second on the Data Highway Plus Switch Assembly SW 6 RS 232 C Communication Rate and Diagnostic Commands You use switch assembly SW 6 to select the communication rate and diagnostic commands for the RS 232 C port on the Series A module Figure C 6 shows the switches on switch assembly SW 6 Figure C 6 The Switches on Switch Assembly SW 6 0 4 N F x Diagnostic commands Communication rate 15228 Mounting the 1785 Module Appendix C Using a Series A 1785 KE Module To set the communication rate you use switches 1 2 and 3 on SW 6 Use the table below to set these switches To set this
34. 7035 What is Data Highway Plus Data Highway Plus is a local area network LAN that allows peer to peer communication among up to 64 nodes You use Data Highway Plus when you want to connect a small number of nodes on a common link Data Highway Plus provides easy re configuration and expansion if you want to add more nodes later Typically you would use Data Highway Plus to connect PLC 5s that need to communicate with each other frequently For example you would use Data Highway Plus to connect a small group of PLC 5s approximately 10 nodes or less involved in a single integrated process Larger links or those in looser configurations could use a Data Highway as a common backbone network Communication on a Data Highway Plus involves a aphysical link layer software layers 2 2 The Physical Link Layer Chapter 2 Overview of the 1785 KE and Data Highway Plus The physical link layer is a set of cables and interface modules that work together to provide a channel for communication between the various points called nodes on the physical link A Data Highway Plus node consists of an interface to Data Highway Plus usually a module The PLC 5 processor has a Data Highway Plus connection built in so it does not need a separate interface module The Data Highway Plus cables consist of a trunkline that can be up to 10 000 feet long and droplines that can be up to 100 feet each You can use your Data Highway Plus
35. C on one of the Data Highway Plus networks to talk to any PLC on the other Data Highway Plus network This is made possible because the Series B module supports the Data Highway Plus remote addressing capability With remote addressing the local 1785 KE node address 013 on Data Highway Plus 1 can be addressed separately from the final destination PLC 5 node address 012 on Data Highway 2 There are no additional restrictions on what the addresses can be when using the Series B 1785 KE to connect two Data Highway Plus networks In the following examples we send PLC 5 read and write commands from a PLC 5 on Data Highway Plus 1 node address 010 to a PLC 5 on Data Highway Plus 2 node address 012 PLC 5 Write Commands This example message instruction writes eight words from the local PLC 5 node 010 integer file 7 word locations 0 through 7 to the remote PLC 5 node 012 integer file 7 word locations 0 to 7 Program a message MSG instruction with the parameters shown below Also you must set up the message instruction for continuous mode by toggling bit N 10 20 11 to ON MESSAGE INSTRUCTION DATA MONITOR FOR CONTROL BLOCK N10 20 Read Write WRITE ignore if timed out 0 TO PLC 5 Data Table Address N7 0 to be retried 0 NR Size in Elements 8 awaiting execution 0 EW Local Remote REMOTE continuous 1CO Remote Station 012 error OER Link ID 00 message done 0 DN Remote Link Type DATA HIGHWAY message transmitting 1ST Loc
36. KGM The 1771 KGM s address 014 must be included in the polling range Note that the PLC 5 s addresses are used in the polling range The 1785 KE s are transparent to the 1771 KGM and are not included in the polling range command rung normal PLC 2 Unprotected Write to PLC 5 node 011 octal The values in the timer accumulators 040 through 043 octal will be written into PLC 5 file 12 decimal element locations 8 through 11 decimal command rung normal PLC 2 Unprotected Read to PLC 5 node 11 octal The values from the timer accumulators that were written to the PLC 5 file 012 decimal element locations 8 through 11 decimal will be read into word locations 044 through 047 octal in the PLC 2 communication zone delimiter rung This rung continuously cycles the command start bit for the normal Unprotected Write command This rung continuously cycles the command start bit for the normal Unprotected Read command timer 040 octal timer 041 octal timer 042 octal timer 043 octal This rung displays the four timer accumulator values that are written to the PLC 5 This rung displays the four timer accumulator values that are read from the PLC 5 To verify that the PLC 2 test program is executing properly check the timer accumulator values in rungs 11 and 12 You should see the timer values in word locations 040 through 043 octal appear in word locations 044 through 047 octal Chapter 5 Communicating T
37. ON ON OFF ON 3 DWN UP UP 3 DWN UP UP ON OFF OFF ON OFF OFF 4 UP DWN DWN 4 UP DWN DWN OFF ON ON OFF ON ON 5 UP DWN UP 5 UP DWN UP OFF ON OFF OFF ON OFF 6 UP UP DWN 6 UP UP DWN OFF OFF ON OFF OFF ON 7 UP UP UP 7 UP UP UP OFF OFF OFF OFF OFF OFF Important The 1785 KE Series B uses the convention DWN ON Binary 0 and UP OFF Binary 1 3 6 3 Installing the 1785 KE Figure 3 5 shows you how to set the node number 37 using Octal Digits 1 and 2 as follows Figure 3 5 Setting the Data Highway Plus Node Address 37 Octal Octal Octal DigitO Digit 1 Digit 2 DOWN UP _ 0 OFF SLA Side View HHBHBBHHB Set both switches to DOWN ON position 17106 Octal Digit 0 Most Significant Digit To set Octal Set switches 3 5 Digit 1 to No 3 No 4 No 5 3 DWN UP UP ON OFF OFF Octal Digit 2 Least Significant Digit To set Octal Set switches 6 8 Digit 2 to No 6 No 7 No 8 7 UP UP UP OFF OFF OFF Important The 1785 KE Series B uses the convention DOWN ON Binary 0 and UP OFF Binary 1 3 7 Chapter 3 Installing the 1785 KE Switch Assembly SW 3 Communication Rates and Local Remote Option 3 8 Switch assembly SW 3 is for s setting the communication rate for the Data Highway Plus network and the RS 232 C link a setting the module for local or remote operation
38. R Size in Elements 8 awaiting execution 0 EW Local Remote REMOTE continuous 1 Remote Station 014 error OER Link ID 00 message done 0 DN Remote Link Type DATA HIGHWAY message transmitting 1ST Local Node Address 21 message enabled 1 EN Processor Type PLC 2 Destination Data Table Address 050 ERROR CODE 0 control bit addr N30 0 8 Press a key for desired function or lt ESC gt or RETURN to exit monitor RUN no forces decimal data decimal addr PLC 5 Addr 11 SIZE IN TOGGLE ELEMNTS BIT F3 F9 Chapter 5 Communicating Through the 1785 KE Module PLC 2 Unprotected Read This example reads the eight words that were written to the PLC 2 data table with the last example This example stores the data in integer file 7 word locations 10 to 17 Program a message MSG instruction with the parameters shown below Also you must set up the message instruction for continuous mode by toggling bit N30 20 11 to ON MESSAGE INSTRUCTION DATA MONITOR FOR CONTROL BLOCK N30 20 Read Write READ ignore if timed out 0 TO PLC 5 Data Table Address N7 10 to be retried 0 NR Size in Elements 8 awaiting execution 0 EW Local Remote REMOTE continuous 1 Remote Station 014 error OER Link ID 00 message done 0 DN Remote Link Type DATA HIGHWAY message transmitting 1 ST Local Node Address 21 message enabled 1 EN Processor Type PLC 2 Destination Data Table Address 050 control bit addr N30 20 11 ERROR CODE 0
39. SR 6 6 signal ground GND 7 7 data carrier detect DCD 8 8 data terminal ready DTR 20 11 transmitted data return TXDRET longline 14 only received data return RXDRET longline 13 only For definitions of each signal refer to Appendix B When communication option switch 5 of switch assembly SW 1 handshaking enable disable is set DOWN the RS 232 C port of the 1785 KE module can transmit or receive all of the above signals refer to Chapter 3 for switch setting information If this switch is UP then the RS 232 C port uses only TXD RXD and GND TXDRET and RXDRET for longlines Important If you select half duplex the 1785 KE uses handshaking signals even if switch 5 is set UP 4 3 Chapter 4 Connecting Your RS 232 C Device to the 1785 KE If you are connecting a 1785 KE module to a device not manufactured by Allen Bradley then you must mount the module within 50 cable feet of that device For such applications the module s GND must be connected to the GND of the modem or computer RXDRET must be jumpered to GND at the module TXDRET should be left open Note that this type of connection does not provide electrical isolation between the module and the connected device The following sections provide guidelines for cabling your 1785 KE to a acomputer a another Allen Bradley communication module amodem 44 Chapter 4 Connecting Your RS 232 C Device to the 1785 KE Direct Connection to a To connect the modul
40. al Node Address 13 message enabled 1 EN Processor Type PLC 5 Destination Data Table Address N7 0 control bit N10 20 11 ERROR CODE 0 Press a key for desired function or lt ESC gt or RETURN to exit monitor RUN no forces decimal data decimal addr PLC 5 Addr 10 SIZE IN TOGGLE ELEMNTS BIT F3 F9 5 8 Chapter 5 Communicating Through the 1785 KE Module PLC 5 Read Commands This example message instruction reads the eight words that were written to the remote PLC 5 node 012 in the last example The instruction stores these words in the integer file 7 word locations 10 through 17 of the local PLC 5 node 010 Program a message MSG instruction with the parameters shown below Also you must set up the message instruction for continuous mode by toggling bit N 10 0 11 to ON MESSAGE INSTRUCTION DATA MONITOR FOR CONTROL BLOCK N10 0 Read Write READ ignore iftimed out 0 TO PLC 5 Data Table Address N7 0 to be retried 0 NR Size in Elements 8 awaiting execution 0 EW Local Remote REMOTE continuous 1 Remote Station 012 error OER Link ID 00 message done 0 DN Remote Link Type DATA HIGHWAY message transmitting 1 ST Local Node Address 13 message enabled 1 EN Processor Type PLC 5 Destination Data Table Address N7 0 control bit addr N10 0 8 ERROR CODE 0 Press a key for desired function or lt ESC gt or lt RETURN gt to exit monitor RUN no forces decimal data decimal addr PLC 5
41. annel between nodes 2 4 Chapter 2 Overview of the 1785 KE and Data Highway Plus The 1785 KE module automatically takes care of the data link layers on the Data Highway Plus network This means that your application programs at the PLCs and computers do not need to bother with inter node protocol handshaking or control of the Data Highway Plus link You must program these layers however for the asynchronous link between your 1785 KE and its RS 232 C device This programming allows your computer to communicate with the Data Highway Plus network through the asynchronous link For more information on the commands protocols and diagnostics used on your Data Highway Plus network refer to the Data Highway Data Highway Plus Protocol and Command Set User s Manual publication 1770 6 5 16 This manual contains the information you need to program the software layers for your computer and troubleshoot your network The Data Highway Plus Protocol The Data Highway Plus link has a communication rate of 57 600 bits per second The Data Highway Plus implements peer to peer communication with a token passing scheme to rotate link mastership among its stations Since this method does not require polling it is time efficient The Data Highway Plus uses factory set timeouts to rebuild the token pass network if a token is lost because of a defective station This timeout is not adjustable The RS 232 C Asynchronous Link Protocols The
42. as that to a 1785 KE in local mode 1 when the 1785 KE Series B is in local mode it functions the same as a 1785 KE Series A As a result Important If you are replacing a 1785 KE Series A with a 1785 KE Series B and desire Series A compatible operation set the Local Remote option switch to Local See Chapter 5 for more information on selecting this option Switch Assembly SW 4 Switch assembly SW 4 is reserved for future use Set the switches in the UP position figure 3 7 Figure 3 7 Switch Assembly SW 4 DOWN UP ON OFF LP Set All switches Side View to UP OFF position 17108 3 9 Chapter 3 Installing the 1785 KE Mounting the 1785 KE Module The 1785 KE module mounts in an Allen Bradley Bulletin 1771 I O rack If you are using a dropline trunkline configuration you must mount the 1785 KE module within 100 cable feet of the Data Highway Plus trunkline When you are connecting the module directly to an RS 232 C device you must mount the 1785 KE module within 50 cable feet of that device If the RS 232 C device is another Allen Bradley communication module you can mount the 1785 KE module up to 7 000 cable feet away from it by using the longline connection discussed in Chapter 4 If you are using a modem link to connect the 1785 KE module to the RS 232 C device then the module and the device may be as far apart as the modem link will allow To install a 1785 KE module in an Allen
43. conjunction with a separate auto dialer Using the 1785 KE in an Auto Answer Application Chapter 4 Connecting Your RS 232 C Device to the 1785 KE The 1785 KE module continually asserts DTR when it is waiting for a call Under this condition a modem attached to the 1785 KE module will answer a call and assert DSR as soon as it detects ringing The 1785 KE module does not monitor the RING indicator signal in the RS 232 C interface Once it detects DSR the module starts a timer approximately 10 seconds and waits for the DCD signal When the module detects DCD communication can start If the module does not detect DCD within the timeout the module turns DTR off This causes the modem to hang up and break the connection When the hang up is complete the modem turns off DSR This causes the module to reassert the DTR line and wait for another call This feature protects access to the phone if someone calling a wrong number reaches the module After detecting DCD the module continues to monitor the DCD line If DCD goes off the module restarts the timeout If DCD is not restored within the timeout the module initiates the hangup sequence This feature allows the remote station to re dial in the event that the connection is lost through a fault in the phone network This handshaking is necessary to guarantee access to the phone line If you defeat this handshaking protocol by improper selection of your modem options or by jumpers a
44. dr 11 Program Verification Chapter 5 Communicating Through the 1785 KE Module To verify that the example programs above are executing properly follow these steps 1 Look at the PLC 5 node 51 octal file contents of integer file 7 by typing DISPLAY MONITOR N7 0 2 Change any value in word locations 0 through 7 in this file 3 These values in word locations 10 through 17 should be the same as the values in word locations 0 through 7 Important These PLCS to PLC5 examples are for testing only Toggling the continuous bit to ON generates high network traffic which in most cases is not necessary Polling More Than One PLC 5 on a Data Highway Plus Since the 1785 KE Series B is transparent to the master remote PLC 5 s can be polled as individual slaves whether there is one or multiple PLC 5 s attached to a given 1785 KE As a result PLC 5 s on a remote DH can be polled as though they were individual slave stations Figure 5 5 illustrates this application Figure 5 5 PLC 24771 KGM 1785 KE 5 21 Chapter 5 Communicating Through the 1785 KE Module Using the Multidrop Expansion Digit As mentioned earlier the valid range of slave addresses on the multidrop network is 001 376 octal 010 077 and 110 376 octal when a 1771 KGM is used as the master The valid range of addresses on Data Highway Plus is 00 77 octal Figure 5 6 Switch Assembly SW 2 Octal Octal Octal Digit 0 Digiti Dig
45. dule Based on the address returned you can use the number of the counters which follow as an offset to calculate a the location of a particular counter how many counter values you want returned 6 3 Chapter 6 1785 KE Diagnostic Tools You can then use this information to format a Diagnostic Read command The reply from the Diagnostic Read command will contain the data stored in the counters For more information on the Diagnostic Status and Diagnostic Read commands refer to the Data Highway Data Highway Plus Protocol and Command Set Reference Manual publication 1770 6 5 16 1785 KE Data Highway Plus Diagnostic Counters The 1785 KE stores 29 diagnostic counters in a total of 35 bytes The following table contains a list of 1785 KE Data Highway Plus diagnostic counter bytes and what they contain Counter Byte What the Counter Contains 0 received ACK with bad CRC 1 timeout expired with no ACK received 2 transmit retries exhausted 3 NAK illegal protocol operation received 4 NAK bad LSAP received 5 NAK no memory received 6 received ACK NAK too short 7 received ACK NAK too long 8 something other than an ACK NAK received 9 token pass timeout 10 token pass retries exhausted 11 claim token sequence entered 12 token claimed 13 bad CRC in received frame 14 illegal protocol operation sent 15 NAK bad LSAP sent 16 NAK no memory sent 17 received frame too small 18 received frame too long 19 rece
46. e Data Highway Plus link comes on and stays lit when an internal hardware fault is detected If the RCVG LED remains lit and the XMIT LED appears to flicker then the module is passing the token or sending messages 6 2 The 1785 Diagnostic Counters Chapter 6 1785 KE Diagnostic Tools The following sections tell you a what a diagnostic counter is a how to read diagnostic counters a what types of information the 1785 KE counters contain What is a Diagnostic Counter A diagnostic counter records an event of interest for debugging the module and for longer term reliability analysis The diagnostic counters occupy a block of the module s internal scratch RAM Most are single byte counters that wrap around to zero when they overflow These counters provide a useful tool for diagnosing problems How to Read Diagnostic Counters To read diagnostic counters you must issue a Diagnostic Read command This command can only be sent from a device connected to a Data Highway Plus module that supports an asynchronous port a that can format the diagnostic commands Therefore a PLC user program is unable to initiate a Diagnostic Read command Important The location of the diagnostic counters in a Data Highway Plus module varies a from module to module a between revision levels of the same type module You must first request the location of these counters by transmitting a Diagnostic Status command to the mo
47. e Length in Feet Maximum Communication Rate in Bits Per Second Up to 2 000 19 200 2 000 to 4 000 9 600 4 000 to 6 000 4 800 6 000 to 7 000 2 400 The receiver can sense the signals generated by a similar transmitter and it is electrically isolated from all other circuitry on the module It consists of an opto isolater circuit with an input and return line at the RS 232 C port other signals on the RS 232 C port are driven and received by standard RS 232 C interface circuits which have maximum drive capability of 50 feet The 1785 KE module sends data serially over the RS 232 C interface one 8 bit byte at a time The transmission format conforms to ANSI X3 16 CCITT VA and ISO 1177 with the exception that the parity bit is retained while the data length is extended to eight bits The transmission format may be summarized as start bit data bit 0 data bit 1 data bit 2 data bit 3 data bit 4 data bit 5 data bit 6 data bit 7 even parity bit optional one stop bit Chapter 4 Connecting Your RS 232 C Device to the 1785 KE Cabling for Your RS 232 C Cabling for the RS 232 C port of the 1785 KE module will vary Device depending on your application In general the pinouts for this cabling are as follows Standard RS 232 1785 KE 15 pin Signal Mnemonic 25 pin Connector Connector chassis shield drain 1 1 transmitted data TXD 2 2 received data RXD 3 3 request to send RTS 4 4 clear to send CTS 5 5 data set ready D
48. e PLC 5 with Data Highway Plus address 011 octal The master sends the message to the PLC 5 address 011 octal The 1785 KE recognizes the address as one of the addresses on the Data Highway Plus link and passes the message through to address 011 The PLC 5 executes the command processes a reply to the master and returns the reply to the 1785 KE Later when the master polls for address 011 the 1785 KE returns the response from address 011 In this communication the 1785 KE is transparent to the master The master is polling and sending messages only to the PLC 5 at address 011 The following example shows the PLC 2 program to send a command from the PLC 2 1771 KGM master at address 014 octal through the 1785 KE to the PLC 5 at Data Highway Plus address 011 octal Important Since the PLC 5 is communicating with a PLC 2 the PLC 5 must have a file set up to look like a PLC 2 data table The PLC 5 file must be the decimal equivalent of the PLC 2 1771 KGM node address Since the PLC 2 1771 KGM is at address 014 octal the PLC 5 must create file 012 014g 01210 to communicate with the PLC 2 5 13 Chapter 5 Communicating Through the 1785 KE Module PLC 2 Program Example 014 077 030 027 1 161 18 8 L 07 014 011 014 027 2 1 1 68 6 00 07 030 011 010 040 043 027 1 1 1 181 81 61
49. e directly to acomputer you can use a data terminal Computer interface cable cat no 1770 CG This cable plugs into the RS 232 C PORT connector on the module and the RS 232 C compatible connector on the computer Connect the cable shield at one end only The 1770 CG cable is 16 5 feet long If you need a longer cable or a male female adapter cable you can construct your own according to the wiring diagram in Figure 4 2 Make sure that the cable length does not exceed 50 feet Figure 4 2 Wiring Diagram RS 232 C PORT Connector to Computer RS 232 C PORT connector of RS 232 C compatible PORT 1785 KE module connector of compute 1770 CG Cable 16 5 ft porer SHLD SHLD GND GND TXD RXD RXD B TXD DSR DTR pco et pcp DTR 6 DSR GND GND RTS RTS tue EL 15 pin Male 25 pin Male Connector Connector 15233 This type of connection includes the DTR signal to allow each end to detect the loss of the other end s ability to communicate If your computer does not provide the DTR signal jumper pins 6 and 8 at the module to pin 11 4 5 Chapter 4 Connecting Your RS 232 C Device to the 1785 KE Connection to Another Communication Module 4 6 You can connect the 1785 KE to another Data Highway interface module with a longline cable This cable can be up to 7 000 feet long However remember that the cable length can limit the communication rate refer to the section earlier in this chapter entitled Electrical
50. e module to a modem you can use the modem interface cable cat no 1770 CP This cable plugs into the RS 232 C PORT connector on the module and the RS 232 C compatible connector on the modem Connect the cable shield at one end only The 1770 CP cable is 16 5 feet long If you need a longer cable or a male female adapter cable you can construct your own according to the wiring diagram in Figure 4 5 Be sure that the cable length does not exceed the RS 232 C limit of 50 feet Figure 4 5 Wiring Diagram RS 232 C PORT Connector to a Modem RS 232 C PORT connector of RS 232 C commpatible PORT 1785 KE module connector of modem 15 pin Male 25 pin Male Connector Connector 15234 4 8 Choosing a Modem for Point to Point Full Duplex Applications Chapter 4 Connecting Your RS 232 C Device to the 1785 KE This section provides guidelines for selecting the modems you use with the 1785 KE in point to point applications using full duplex protocol The modem you use to interface to an Allen Bradley RS 232 C communication module using full duplex protocol must be capable of a supporting the standard RS 232 C handshaking described in Appendix B supporting the baud rate of your module operating on a full duplex link a interfacing to an asynchronous device a operating in a transparent mode data is passed over the link without being modified Note If handshaking is enabled via the SW 1 switch selection discus
51. em is operational and ready for communication If the 1785 KE module is in half duplex mode or in full duplex mode with handshaking enabled via the SW 1 switch selection discussed in Chapter 3 the 1785 KE requires the DSR signal to communicate The module will not transmit or receive unless DSR is on This signal is typically continually asserted by the modem except during an auto answer application such as the one discussed in Chapter 4 If the modem does not properly control DSR or if no modem is used DSR must be jumpered to a high signal at the module s RS 232 C connector Since DTR is held high by the module DSR can be jumpered to DTR In auto answer applications DSR is a signal from the modem to the module that the phone is off hook It is the modems answer to Appendix Definitions of RS 232 C Handshaking Signals Signal DCD data carrier detect TXDRET transmifted data return RXDRET received data return What it Does is a signal from the modem to the module to indicate that the carrier from another modem is being sensed on the link If the 1785 KE module is in half duplex mode or in full duplex mode with handshaking enabled via the SW 1 switch selection discussed in Chapter 3 the 1785 KE requires the DCD signal to communicate modem does not properly control DCd or if a modem is not being used DCD can be jumpered to DTR at the module In auto answer applications DCD should not be ass
52. ends command to the 1785 KE M ADDRESS DLE STX DST SRC CMDSTS TNS TNS FNC PO TT TT NL N 1 0 1 5 NL SIZE DLE ETX BCC 10 02 29 20 OF 00 47 OL 00 00 04 00 00 24 4E 31 30 31 35 00 08 10 03 2 1785 KE responds to computer DLE ACK 10 06 3 1785 KE sends command to the PLC 5 The 1785 KE sends the command onto Data Highway Plus and the PLC 5 node at address 51 octal 4 PLC 5 sends the reply to the 1785 KE The PLC 5 receives the command executes the command formats a reply and sends the reply back to the 1785 KE 5 1785 KE sends the PLC 5 reply back to the computer DLE STX DST SRC CMD STS TNS DATA DLE ETX BCC 10 02 20 29 4F 00 47 01 22 11 44 33 66 55 8877 10 03 BC 6 Computer responds to the 1785 KE OLE ACK 10 06 5 6 Application 2 Communicating Between Two Data Highway Plus Networks Chapter 5 Communicating Through the 1785 KE Module Figure 5 2 shows application involving communication between two Data Highway Plus networks through a full duplex link between two Series B 1785 KE modules Figure 5 2 Connecting Two Data Highway Plus Networks PLC 5 011 PLC 5 010 17049 5 7 Chapter 5 Communicating Through the 1785 KE Module When using a 1785 KE in this application it should be set for Remote mode by setting the Remote Local option switch refer to Chapter 3 When in Remote mode the Series B 1785 KE module allows any PL
53. er is attached to the Data Highway Plus via the RS 232 C connection to the 1785 KE In this configuration the computer assumes the address of the 1785 KE on the Data Highway Plus i e the computer and 1785 KE are addressed as a single node on the Data Highway Plus As a result messages sent from other nodes on the Data Highway Plus to the computer will use the address of the 1785 KE as the destination address Messages sent from the computer to other nodes on the Data Highway Plus will use the address of the 1785 KE as the source node address The following example will use the system of figure 5 1 to illustrate commandis initiated by the computer to PLC 5 051 The full duplex protocol is used in the examples You may wish to refer to Appendix D Interprocessor Addressing for further background information on communicating from a computer to a PLC 5 Computer to PLC 5 In this example we show the computer sending the following commands to the PLC 5 a PLC 2 read and write commands a PLC 3 read and write commands We display the command formats that are sent over the RS 232 C link as they would appear on a line monitor placed between the computer and its 1785 KE Data Highway Plus module all line monitor printouts are shown in hex Full duplex protocol is used In this example a computer 1785 KE node address 040 octal 020 hex PLC 5 node address 051 octal 029 hex Important If the computer sends PLC 2 type co
54. erted unless the phone is off hook is the return signal for TXD It is connected to module logic ground through a resistor It does not conform to RS 232 C specifications is the return signal for RXD It is connected to the isolated receiver and is isolated from all other circuitry on the module It does not conform to RS 232 C specifications Appendix Objectives Replacing a Series A Module with a Series B Module Appendix C Using a Series A 1785 KE Module The Series A version of the 1785 KE has the following differences from Series B a limited communication applications different option switches a different front cover and connectors The following sections describe the differences for each of these areas The Series A module operates like a Series B module in local mode If you are replacing a Series A 1785 KE with a Series B and want the operation to be compatible with your Series A module set the Local Remote switch on the Series B module to Local Refer to Chapter 3 for more information Appendix Using a Series A 1785 KE Module Setting the Communication Option Switch Select this switch assembly SW 1 SW 2 SW 3 SW 4 SW 5 SW 6 Figure C 1 The Series module has 6 switch assemblies figure C 1 that enable you to select various communication options The switch assemblies and their corresponding options are For this communication option RS 232 C link features not used switches m
55. hrough the 1785 KE Module Example 2 Slave to Master Communication In this example we send a message from the PLC 5 with Data Highway Plus address 011 octal through the 1785 KE at address 021 octal to the master 1771 KGM PLC 2 at multidrop address 014 octal In this case the PLC 5 sends the command to local destination address 021 remote destination address 014 The command remains in the 1785 KE address 021 buffer until the master polls address 011 The 1785 KE recognizes address 011 as a PLC 5 on its Data Highway Plus link and sends the command to the master When the master finishes processing the reply it sends it to the PLC 5 through the 1785 KE The 1785 KE 15 transparent to the master The following examples show the T50 message instructions necessary to send PLC 2 Unprotected Read and Unprotected Write commands from the PLC 5 address 011 octal to the master address 014 octal through the 1785 KE PLC 2 Unprotected Write This example writes eight words from integer file 7 word locations 0 through 7 to the PLC 2 1771 KGM master node 014 octal data table words 050 through 057 octal Program a message MSG instruction with the parameters shown below Also you must set up the message instruction for continuous mode by toggling N30 0 11 to ON MESSAGE INSTRUCTION DATA MONITOR FOR CONTROL BLOCK N30 0 Read Write WRITE ignore if timed out 0 TO PLC 5 Data Table Address N7 0 to be retried 0 N
56. ia e Cyprus e Czech Republic e Denmark e Ecuador e Egypt El Salvador Finland e France e Germany Greece e Guatemala e Honduras e Hong Kong Hungary e Iceland e India Indonesia e Ireland e Israel Italy e Jamaica Japan e Jordan Korea e Kuwait e Lebanon e Malaysia e Mexico e Netherlands e New Zealand e Norway Pakistan e Peru e Philippines e Poland e Portugal e Puerto Rico e Qatar e Romania Russia CIS e Saudi Arabia e Singapore Slovakia Slovenia e South Africa Republic e Spain e Sweden Switzerland e Taiwan e Thailand Turkey e United Arab Emirates e United Kingdom e United States e Uruguay Venezuela e Yugoslavia Allen Bradley Headquarters 1201 South Second Street Milwaukee WI 53204 USA Tel 1 414 382 2000 Fax 1 414 382 4444 Publication 1785 6 5 2 May 1989 PN 404611004 Supersedes Publication 1785 6 5 2 February 1989 Copyright 1989 Allen Bradley Company Inc Printed in USA
57. it 2 KEY DOWN _ ON _ FD 1 Data Highway Plus OFF Node Address 2 Lower Two Digits of Multidrop Address Side View Multidrop Em Address Expansion Digit Octal Digit 0 Multidrop Address Expansion Digit To set Octal Set switches 1 2 Digit 1 to No 1 No 2 0 DWN ON DWN ON 1 DWN ON UP OFF 2 UP OFF DWN ON 3 UP FF UP Q0FF Important The 1785 KE Series B uses the convention DOWN ON Binary 0 and UP OFF Binary 1 Note from the figure that three octal digits are available Octal Digit 0 Octal Digit 1 and Octal Digit 2 5 22 5 Communicating Through the 1785 KE Module Use Octal Digits 1 and 2 to set the 1785 KE s Data Highway Plus address from 00 77 These digits also set the lower two digits of the 1785 KE s address on the multidrop network Octal Digit 0 is a multidrop address expansion digit It sets the most significant highest digit of the 1785 KE multidrop address If you need to use multidrop addresses higher than 000 077 you will need to set this digit to 1 2 or 3 Figure 5 7 below shows an example of using this digit Figure 5 7 Multidrop Network PLC 5 3 12 Key x xx Address on RS 232 Multidrop xx Address on local Data Highway Plus 5 23 Chapter 5 Communicating Through the 1785 KE Module 5 24 As you can see from the figure the value of Digit 0 determines both the address of the 1785
58. ived a retransmission of a frame 20 received frame aborted line noise 21 22 message successfully sent low byte first 23 24 message successfully received low byte first 25 26 command successfully sent low byte first 27 28 reply successfully received low byte first 29 30 command successfully received low byte first 31 32 reply successfully sent low byte first 33 reply could not be sent 34 number of active nodes 6 4 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 Chapter 6 1785 KE Diagnostic Tools What the Counter Contains count of messages attempted count of messages sent and ACKed count of ACKs received count of ACKs passed from RX to TX count of NAKs received count of NAKs passed from RX to TX count of timeouts waiting for a response count of ENQ s sent count of messages that could not be sent count of replies that could not be forwarded count of messages received count of ACKs sent count of NAKs sent count of ENQs received count of retransmissions received and ACKed count of STX or SOH received count of messages ignored count of messages aborted by DLE ENQ count of messages aborted by control code other than ENQ count of ACKs but no memory for next message count of NAKs sent because of no memory count of broadcasts received count of broadcasts received successfully coun
59. ltidrop link operating in switched carrier mode under handshake control a interfacing to an asynchronous device operating in a transparent mode data is passed over the link without being modified a minimal RTS CTS delay time for optimum performance This time is typically determined by the time it takes the modem to turn the carrier on Chapter Objectives Application 1 Connecting a Computer to Data Highway Plus Chapter 5 Communicating Through the 1785 KE Module In this chapter we discuss three typical applications of the 1785 KE module a connecting an intelligent RS 232 C device such as a computer to Data Highway Plus through a point to point RS 232 C link local mode full or half duplex protocol connecting two Data Highway Plus networks together over a point to point modern link remote mode full duplex protocol a connecting a Data Highway Plus node such as a PLC 5 as a slave on a multidrop link through a modem remote mode half duplex slave protocol When you connect a computer or other intelligent RS 232 C device to Data Highway Plus figure 5 1 you select the local mode option and either full or half duplex protocol Refer to Chapter 3 for more information on setting the 1785 KE option switches Figure 5 1 Connecting a Computer to Data Highway Plus Computer iis PLC 5 1052 2 HEX Chapter 5 Communicating Through the 1785 KE Module 5 2 The comput
60. mmand to the PLC 5 then the PLC 5 must create a PLC 2 compatibility file number 32 computer node address 040 octal 2 032 decimal This file must look like a PLC 2 data table to the computer If the computer sends a PLC 3 type command with a four level extended address to the PLC 5 the command will be able to access any file in the PLC 5 data table Chapter 5 Communicating Through the 1785 KE Module For information on creating an RS 232 C asynchronous link driver for your computer refer to the Data Highway Data Highway Plus Protocol and Command Set Reference Manual publication 1770 6 5 16 PLC 2 Normal Unprotected Write This example writes 4 words 8 bytes of data to the PLC 5 s PLC 2 compatibility file file 32 word locations 20 through 23 The following paragraphs show line monitor examples for this command 1 Computer sends command to the 1785 KE DLE STX DST SRC CMD STS TNS TNS ADR ADR DATA DLE ETX BCC 10 02 29 20 08 00 4 01 28 00 22 11 44 33 66 55 88 77 10 03 DE 2 1785 KE responds to computer DLE ACK 10 06 3 1785 KE sends command to the PLC 5 The 1785 KE sends the command onto Data Highway Plus and the PLC 5 node at address 51 octal 4 PLC 5 sends the reply to the 1785 KE The PLC 5 receives the command executes the command formats a reply and sends the reply back to the 1785 KE 5 1785 KE sends the PLC 5 reply back to the computer DLE STX DST SRC CMD
61. nections to the 1785 KE connect the 1770 CD cable to the screw terminals on the top 3 pin connector figure 3 9 If you are using a trunk drop configuration for details on how to construct the dropline refer to the Data Highway Cable Assembly and Installation Manual publication 1770 6 2 1 Figure 3 9 Connecting the 1785 KE to a Data Highway Plus Network Terminals on 3 pin terminal block 2 2 Twinaxial cable cat no 1770 CD Shield 15 pin connector ona communication Interface Module Shield Clear 1770 SC 17046 If the 1785 KE is an end device in the Data Highway Plus Network you must install a 150 ohm resistor on the 3 position terminal block or in the station connector cat no 1770 SC Powering Up the 1785 KE Module Chapter 3 Installing the 1785 KE When you have successfully a set the switch assemblies on the 1785 KE to the setting suited to your application a mounted your 1785 KE module in a 1771 VO rack following the procedure earlier in this chapter a connected your module to the Data Highway Plus a connected your RS 232 C device to your 1785 KE refer to Chapter 4 you are ready to power up your 1785 KE module To power up your module perform an orderly power up of the 1 0 rack and system PLC At power up the 1785 KE module runs tests to check the integrity of its internal memory timers and firmware Any failure causes the red ERR indicator on the f
62. nual a where to locate information on related products This manual describes the 1785 KE Data Highway Plus RS 232 C Interface Module It gives you procedures for a installing the 1785 KE a troubleshooting your 1785 KE For more information on programming and troubleshooting Data Highway Plus and Data Highway interface modules refer to the Data Highway Data Highway Plus Protocol and Command Set Reference Manual publication 1770 6 5 16 You should read this manual before attempting to install or use the 1785 KE We assume that you are already familiar with a RS 232 C standards and practices a your RS 232 C device or modem Allen Bradley Programmable Logic Controllers PLCs Series Enhancements Frequently Used Terms Chapter 1 Using This Manual This manual describes both Series A and Series B versions of the 1785 KE module Table 1 A lists the Series B enhancements to the module These features were not available on the Series version of the module Where we describe these features later in the manual we note that they are only available on the Series B version of the module You can see the catalog number and the series level of the module on the name plate on the side of the module Table 1 A Series B Enhancements Feature Benefit Enhanced communications capability for applications involving point to point modem links Remote Addressing Capability Full Duplex Operation Enhanced communications ca
63. ons of RS 232 C Handshaking Signals le len leo m I ko loo N NKEBRBEEBSBBERESE i S ko A lO amp lo le le loo Table of Contents Using a Series A 1785 KE Module Appendix Objectives Replacing a Series A Module with Module Setting the Communication Option Switch Switch Assembly SW 1 RS 232 C Link Features Switch Assembly SW 2 For Future Use Switch Assemblies SW 3 and SW Node Number Switch Assembly SW 5 Network Link Communication Rate Switch Assembly SW 6 RS 232 C Communication Rate and Diagnostic Commands Mounting the 1785 KE Module Making Connections to the Series A 1785 KE Interprocessor Addressing Appendix Addressing How to Address a PLC 5 From 2 Addressing a PLC 5 From a PLC 3 Communicating From a Computer to 5 lo le le In loo N lo len 1 Chapter Objectives Purpose of This Manual Who Should Read This Manual Chapter 1 Using This Manual After reading this chapter you should know a if this manual contains the information you need a where to locate information in this ma
64. or not the RS 232 C port of the Series A module can delete duplicate messages transmitted to it If you want the module to Set switch 3 detect and ignore duplicate messages ON accept all messages regardless of OFF duplication Switch 4 determines whether the RS 232 C port on the Series A module uses and recognizes the following handshaking signals a data set ready DSR requests to send RTS a clear to send CTS s data carrier detect DCD a data terminal ready DTR If you want the port to Set switch 4 use handshaking signals ON ignore handshaking signals OFF Switch Assembly SW 2 For Future Use Switch assembly SW 2 is for future use You must set both switches on switch assembly SW 2 to OFF figure C 3 Figure C 3 Setting Switch Assembly SW 2 012 N Set both 0 switches OFF F 15225 Appendix Using a Series A 1785 KE Module Switch Assemblies SW 3 and SW Node Number Switch assemblies SW 3 and SW 4 are for setting the node number of the 1785 KE module The node number is an encoded 2 digit octal number that identifies the Series A module as a unique node on Data Highway Plus Valid node numbers for the Series A module are 00 to 77 octal Figure C 4 shows you how to set the node number using switch assemblies SW 3 and SW 4 Use the switches in assembly SW 3 to set the first left most digit a SW 4 to set the second right most digit Figure C 4 Setting Switch Assemblies SW 3 and SW
65. pability for applications involving multidrop modem links Remote Addressing Capability Half Duplex Operation The Series B version of the 1785 K module uses different communication option switches and has a different front cover and Data Highway Plus connectors than the Series A version Information on setting the Series A is included in Appendix C for reference In this manual we use the following terms This Term Means Data Highway Plus formerly Peer Communications Link PCL link a Data Highway or Data Highway Plus network local node node on local link remote node node on remote link 1 3 Chapter 1 Using This Manual Precautionary Notes In this manual you will see WARNINGS to tell you where you may be injured if you do not follow procedures properly a CAUTIONS to tell where equipment may be damaged if you do not follow procedures properly a Important notes that stress information that is critical to your understanding and use of the product Related Products The 1785 KE Data Highway Plus RS 232 C Interface Module is part of the Data Highway Plus product family Related products include Product Catalog Number Data Highway or Data Highway Plus Asynchronous 1770 KF2 RS 232 C or RS 422 A Interface Module Data Highway Plus to Data Highway 1785 KA Interface 1785 KA Module Data Highway Plus PLC 2 Family Communication 1785 KA3 Adapter Module PLC 3 I O Scanner Communication Adapter Module 1775 85
66. ppendix D Interprocessor Addressing If your computer executes the basic Command Set CMD 01 CMD 08 PLC 5 Commands or PLC 3 Word Range Read or Write CMD OF and Then your computer access data from a single file in the PLC 5 data table This file automatically defaults to the file number that is the decimal equivalent of the octal node address of the computer s interface module For example if the computer the computer s octal node address is 20 the computer would read from and write to PLC 5 file 16 20 octal 16 decimal You can change the default file to any file in a PLC 5 by issuing a Modify PLC 2 Compatibility File command all files in the PLC 5 data table The computer must have the capability to format the appropriate packet in logical ASCII or logical binary format Oe Rockwell Automation Allen Bradley a Rockwell Automation Business has been helping its customers improve pro ductivity and quality for more than 90 years We design manufacture and support a broad range Allen Bradley of automation products worldwide They include logic processors power and motion control devices operator interfaces sensors and a variety of software Rockwell is one of the worlds leading technology companies Worldwide representation Argentina e Australia e Austria e Bahrain e Belgium Brazil e Bulgaria e Canada Chile e China Colombia e Costa Rica Croat
67. rate in Set these switches bits per second 1 2 3 110 OFF OFF OFF 300 ON OFF OFF 600 OFF ON OFF 1200 ON ON OFF 2400 OFF OFF ON 4800 ON OFF ON 9600 OFF ON ON 19200 ON ON ON To set diagnostic commands you use switch 4 on SW 6 Use the table below to set switch 4 If you want your module to Set switch 4 execute diagnostic commands ON pass through diagnostic commands OFF The 1785 KE module mounts in an Allen Bradley Bulletin 1771 I O rack If you are using a dropline trunkline configuration you must mount the 1785 KE module within 100 cable feet of the Data Highway Plus trunkline When you are connecting the module directly to an RS 232 C device you must mount the 1785 KE module within 50 cable feet of that device If the RS 232 C device is another Allen Bradley communication module you can mount the 1785 KE module up to 7 000 cable feet away from it by using the longline connection discussed in Chapter 4 If you are using a modem link to connect the 1785 KE module to the RS 232 C device then the module and the device may be as far apart as the modem link will allow Appendix Using a Series A 1785 KE Module Making Connections to the The 1785 KE module has 3 connectors on its front edge figure C 7 Series A 1785 KE Figure C 7 The Connectors on the Series A 1785 KE Connector for Data Highway Plus Connector for the 1784 T50 Industrial Terminal Connector for an RS 232 C device 2
68. ront panel to flash Important The test cycle during power up takes approximately 10 seconds This delay is normal operation for the module For troubleshooting information refer to the Data Highway Data Highway Plus Protocol and Command Set Reference Manual publication 1770 6 5 16 3 13 Chapter Objectives The RS 232 C PORT Connector Chapter 4 Connecting Your RS 232 C Device to the 1785 KE In this chapter we give you guidelines for connecting your RS 232 C device to the 1785 KE For definitions of handshaking signals refer to Appendix B You connect your RS 232 C device to the RS 232 C PORT connector figure 4 1 on your 1785 KE module The RS 232 C PORT connector a female 15 pin D shell does not conform strictly to the RS 232 C standard which specifies a 25 pin male connector However you can use an RS 232 C adapter cable cat no 1770 CG or 1770 CP to interface between this connector and a standard 25 pin connector Figure 4 1 The RS 232 C PORT Connector on the 1785 KE RS 232 C PORT 17047 Chapter 4 Connecting Your RS 232 C Device to the 1785 KE Electrical Characteristics of the RS 232 C Port Character Transmission 4 2 Input and output levels on the RS 232 port conform to the RS 232 C standard The transmitter has increased capability to drive an isolated line that is up to 7 000 feet long The length of this line determines the maximum communication rate on the RS 232 C link Lin
69. sed in Chapter 3 and the DCD signal is lost for more than approximately 10 seconds the 1785 KE follows the handshaking sequence described in the section Using the 1785 KE in an Auto Answer Application later in this chapter If your modem does not support this sequence you can either disable handshaking or with handshaking enabled jumper DTR to DSR at the module to insure the module will recover after DCD is restored The 1785 KE can communicate via modems over either a dedicated link such as a leased phone line a dial up link 4 9 Chapter 4 Connecting Your RS 232 C Device to the 1785 KE The types of dial up network modems that you can use are s Manual These are typically acoustically coupled modems The connection is established when human operators at both ends insert the telephone handsets into couplers to complete the connection a DTE controlled answer These unattended moderns are directly connected to the phone lines The module serving as the data terminal equipment DTE controls the modem through the DTR DSR and DCD signals The module incorporates timeouts and tests to properly operate these types of modems See the section Using the 1785 KE in an Auto Answer Application below for details Auto answer These modems have self contained timeouts and tests and can answer and hangup the phone automatically The module has no means of controlling an auto dial modem but it can be used in
70. t of messages not for this station count of EOTs sent count of calls received count of times before phone hung up count of times DCD lost count of hang ups due to DCD time out 6 5 Appendix Specifications Communication Rates a Data Highway Plus 57 600 bits per second RS 232 C Port Switch selectable from 110 to 19200 bits sec Functions Interface a programmable RS 232 C compatible device with an Allen Bradley Data Highway Plus network Location 1771 I O Rack Communicating Ports a Data Highway Plus 3 screw terminal block a 1784 T50 Terminal 9 pin male D shell connector Asynchronous RS 232 C 15 pin female EIA D shell connector Cabling a Asynchronous RS 232 C Data Terminal Interface Cable cat no 1770 CG or equivalent or Modem Interface Cable cat no 1770 CP or equivalent a Data Highway Plus User supplied Data Highway Plus dropline cable Belden 9463 Power Requirements a 12A 5VDC Ambient Temperature Rating a 32 F to 140 F 0 C to 60 C operational a 40 F to 185 F 40 C to 85 C storage Ambient Humidity Rating Ambient Humidity Rating wm 5 to 95 noncondensing Definitions of RS 232 C Handshaking Signals The table below gives definitions for each signal Signal TXD transmitted data RXD received data RTS request to send CTS clear to send DTR data terminal ready DSR data set ready What it Does
71. t the connectors the modem may still answer a call but if the connection is lost the modem will not hang up It will then be impossible for the remote station to re establish the connection because it will get a busy signal You can connect the module to standard American dialup modems and some European modems Other European standards specify that the DTR signal will make the modem answer the phone whether it is ringing or not This causes the phone to always be busy Since the 1785 KE module asserts signal while waiting for a call you cannot use the 1785 KE with such modems 4 11 Chapter 4 Connecting Your RS 232 C Device to the 1785 KE Choosing a Modem for Multidrop Half Duplex Applications This section provides guidelines for selecting the modems you use with the 1785 KE in multidrop applications using half duplex protocol The multidrop link may either be a two circuit system master sends and slaves receive on one circuit slaves send and master receives on the other or a one circuit system master and slaves send and receive on the same circuit The half duplex protocol is a polled protocol that only allows one node to transmit at a time Because of this the modems must operate in switched carrier mode they only switch their carriers on when they transmit data The RS 232 C handshaking lines are used to control the switching of the carrier for a message transmission as follows figure 4 6
72. to connect such nodes as RS 232 C devices attached to a 1785 KE or a 1770 KF2 Data Highway modules attached via their RS 232 C port to a 1785 KE or a 1770 KF2 a PLC 3 or PLC 3 10 attached to a 1775 S5 SR5 a PLC 2 family device attached to a 1785 K A3 PLC 5s direct connection a T50 industrial terminal a 1785 KA connected to a Data Highway network Figure 2 2 illustrates a typical Data Highway Plus network 2 3 Chapter 2 Overview ofthe 1785 KE and Data Highway Plus Figure 2 2 A Typical Data Highway Plus Configuration PLC 5 PLC 5 PLC 5 1785 KE Module PLC 3 PLC 2 30 775 KA 1771 KG 1785 KE 1785 KE 1785 KE 1785 KE 1704 0 Module Module Module Module Terminal Data Highway Plus 1770 KF2 PLC 5 PLC 5 PLC 5 1785 KA To Data Highway 17036 Important A computer connected to a 1785 KE module cannot access a node on a Data Highway through a 1785 KA module Also nodes on Data Highway cannot access a computer connected to a 1785 KE on Data Highway Plus The Software Layers Both Data Highway Plus and the 1785 KE s RS 232 asynchronous link require two layers of software to enable communication to take place The layers are defined as follows Application layer controls and executes the actual tasks or commands specified in the communication between nodes a Data link layer controls the flow of communication over the physical link by establishing maintaining and releasing the communication ch
73. ust be OFF node number network link communication rate RS 232 C link communication rate and parity Location of the Assemblies on the Series A 1785 KE Module Station number SW 3 and SW 4 For future use SW 2 RS 232 C link features SW 1 4 di Network link communication rate SW 5 RS 232 C link communication rate and parity SW 6 o t EL ANS ZO Front view ON ON OFF OFF OFF Side view 15223 Appendix Using a Series A 1785 KE Module Switch Assembly SW 1 RS 232 C Link Features Figure C 2 shows you the five switches in Switch Assembly SW 1 Figure C 2 The Switches on Switch Assembly SW 1 t See table below RS 232 C handshaking signal lines Duplicate message detection See table below See table below 15224 The following table shows you how to set switches 1 2 and 5 for the module options you require If you want to With error check with parity as With embedded Set these SW 1 switches select protocol as responses as 1 2 5 fullduplex BCC none no OFF OFF OFF fuldlx BCC een no ON OFF OFF fullduplex BCC mme OF ON ON fullduplex BCC even yes ON ON OFF hafduhx BCC mm nm OF OFF hafdulx BCC een no ON OFF OFF fuldpex CRC nme ys OF ON 0O0N 7 hafdpex CRC ne no ON ON ON Appendix Using a Series A 1785 KE Module C4 Switch 3 determines whether

1785-6.5.2, 1785-KE Data Highway Plus Communication Interface

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