1779-6.5.3,Data Highway II PLC-2 Family Interface User Manual
Contents
1.2. 1772 TC Cable Industrial 10 ft 8 Terminal Compatible es with the PLC Processor o Bl at s P Rod 22 IER ee rel 2 ae PLC Processor ee nee d 4 11 Chapter 4 Installing the PLC 2 DHII Interface To 1770 RG Module To use a PLC 2 Family Report Generation Module Cat No 1770 RG with the processor connect a 1771 CN CO or CR cable from the PROGRAM INTERFACE connector on the interface to the PROCESSOR connector on the 1770 RG module Figure 4 9 Figure 4 9 Connection to a 1770 RG Module 1770 RG Module o E 6 Li 8 Interconnect Cable cat no 1771 CN 1 5 ft cat no 1771 CO 3 5 ft cat no 1771 CR 10 ft oO Qr poy o e p m S PLC Processor hon se ng cie ge 24 4 12 Chapter 4 Installing the PLC 2 DHII Interface To Second PLC 2 DHII Interface To use two PLC 2 DHII interfaces for a second Data Highway II link connect a 1771 CN CO or CR cable from the PROGRAM INTERFACE connector on the first interface to the PROCESSOR connector on the second interface Figure 4 10 Figure 4 10 C
3. 2 O e e c Local Node i o 31 B i m Processor f f Gl a 9 c d PLC d 2 20 Remote Fault e Possible Sources e Remote Node Processor Program Load i or PROG Mode 8 e Command Not Executed due to Switch 8 Setting at Remote Node e Fault at Remote Node Processor p8q peo e Power Off at Remote Node Processor F CEDENS Error Detected in Communication Zone of Program at Remote Node Processor APER 22 SAE Pl EET ee een NEE ETETE Chapter 5 Programming the Local Host Immediately before it sets a remote or local fault bit ON the PLC 2 DHII interface enters a four digit error code into the error code storage word The error code storage word is described in the discussion on Error Word By monitoring fault bits in the program operator personnel can be alerted to hardware conditions which prevent normal transmission and execution of commands Programming techniques for monitoring fault bits are described in the discussion about Initiating and Monitoring Commands Error Word When the PLC 2 DHII interface cannot carry out a command due to a programming error or a discrepancy in data it writes an error code into the error word you select in the header rung of the communication zone This word stores the mos
4. 4 6 4 Y 6 51 2 e fo 6 4 86 di 2 ie TOO OU OO OO OO OT TE ip 41 oll C TEEEEEEEEEEEEEER RN 6 4 e 3 AT OD Oy Oo Oe Or SO o gro a o Uo 0 C PROELELEOEDEUCELEOR ECE C ELECBCEL C EO CELLS RS 6 e Y Y The temperature of the air must not excceed 60 C 140 F at any point immediately below any chassis This may limit how high chassis can be mounted an enclosure 10913 1 4 3 Chapter 4 Installing the PLC 2 DHII Interface Mounting the PLC 2 DHII Figure 4 2 shows the mounting dimensions for the PLC 2 DHII interface Interface After drilling and tapping Interface the three holes in the enclosure backpanel start the mounting bolt into the bottom hole You can then hold the interface in place resting it on the bottom bolt while you start the top mounting bolts Figure 4 2 Mounting Dimensions 3 8 in 97mm 7 1 9 in Use 0 25 in mounting bolts 48mm 3 Places E k O L9 9 14 25 in 15 25 in 362 mm 387 mm lejejelsisle eoo 3 6 5 Fr 165 gt Clearance depth including cable connectors is 11 inches 280 mm 4 4 Settin
5. The ladder diagram program must monitor the remote and local fault bits for each command The recommendations that follow concern two methods for monitoring fault bits and using these bits to signal a fault condition Diagnostic Fault Rungs The purpose of remote local fault bit monitoring is to control one or more output indicators to signal a fault condition Fault indicators controlled for this purpose may be as simple as an annunciator or as complex as a printer or CRT terminal used to display a fault message By controlling the fault indicator device the user program can alert personnel to the nature and location of a fault condition To monitor the remote and local fault bits the programmer must understand their timing relationship to the corresponding start bit Figure 5 15 summarizes this relationship The discussion Controlling the Start Bit showed how you can program the fault bits to unlatch the start bit in a fault situation and thus provide automatic retries through the program When used in this manner however a fault bit will be rapidly cycled ON and OFF if a fault is detected Because the fault bit can be constantly changing state at a rapid rate the program must use some method of detecting this transient state of any fault bit and controlling the output device based on this state Figure 5 21 shows a simple method for the control of a fault indicator Here either the remote or local fault bit can turn on the ou
6. 5 12 The link designation tells what link the remote node is on It allows you to send messages off the local link via bridges when you have bridging capability The node designation is the address of the remote node within its local link The node designation must match the three digit number you select on the link address thumbwheel on the remote interface The user designation specifies the user of the node There is only one user of a PLC 2 DHII interface the PLC 2 processor On the 1779 KFL foreign device interface there are two users the devices connected to Channels 1 and 2 The user designation can be set from 11 30 octal which selects Users 1 16 decimal Pick a user number from 1 16 add 8 to it then convert to octal and enter it When you are sending to the KFL User Designation 1 or 2 selects Channel 1 or 2 For example if you want to write to the second channel of a KFL you d put a 012 2 Very often you will be sending messages to another PLC on your own link In this case the link designation 1s that of the local link and the user designation is 1 To ease the coding of communication zone rungs you can leave the link and user portions off of the rung in this case In fact whenever you send messages to a node on your own link you may leave the link portion off the rung Likewise whenever you send to a node with only one possible user as in the PLC 2 and PLC 3 you can leave the user portion off th
7. With the removable frame pulled out the host board switches are exposed on the left side of the removable frame assembly On the left side of the stationary frame is a label that indicates the function of each host board switch Figure 4 4 4 5 Chapter 4 Installing the PLC 2 DHII Interface Figure 4 4 Host Board Switches 1779 KP2 KP2R LEGEND ON w Option Enabled MEN ON OFF OFF Option Disabled MES ON White Is Depressed PROTECTION OPTIONS 2 Accepts Writes to Program Area Accepts Writes to Data Table Accepts Network Parameter Changes Accepts Third Party Requests t e N 02 ouw Reserved Reserved ERU OPEN OFF e KP2 SPECIFIC OPTIONS Reserved 54 Reserved m 4 Reserved a Reserved MEM 7 02 OPEN OFF COMMUNICATION PARAMETERS First Position from Processor _ Reserved N tt ht 02 oru The switches are in four switch assemblies In this publication we show and describe switches as being ON or OFF Printed on the actual switch assemblies are the words ON and OFF or the word OPEN OPEN corresponds to OFF These switch assemblies are identified by the nomenclature S2 through S5 This designation is printed o
8. NU Allen Bradley Data Highway Il PLC 2 Family Interface Cat No 1779 KP2 KP2R User Manual Table of Contents Using This 1 1 Chapter 21 1 Manual s Purpose 21 1 PUCIGNCE 1 1 Vocabulary tan oe Re exe dee DERE 21 1 Manual Organization 1 2 Chapter Summary 1 2 Introducing the PLC 2 DHII Interface 2 1 Chapter 2 1 What Is the PLC 2 DHII Interface 2 1 What Is Its Function 2 3 Compatible Processors 2 4 Communication 5 2 4 Node ed darc beds 2 5 Data Highway Il 25 Media Access Method 2 9 Bridges to Other Data Highway Il Links 2 10 Command Reply 2 10 Message Priority 2 14 Redundant Cabling 2 17 Second Link 2 18 Chapter Summary 2 18 Installing Data Highway Il L
9. Remote Station Local Host Data Start Bit Table Boundaries m d z AAA CCC DDD 027 a BB 07 Fag ne eRe TUN me zl Immediate Access Block Number Legend AAA Link address of remote node BB Number of immediate access blocks at remote node CCC Beginning local word address where block is placed after being read from remote node DDD Ending local word address where block is placed after being read from remote node Chapter 5 Programming the Local Host Status Words 5 16 Notice the format used in the read and update immediate ee eae i The formatis the data and put it here Read 9 6 Ve aal Examine Start Bit Assign a unique start bit to each command rung The start bits are examined by the PLC 2 DHII interface When you turn on the start bit the PLC 2 DHII interface carries out the programmed command Assign a unique start bit to each immediate access update rung and each command rung Use the ladder diagram program to turn on the start bit whenever and as often as your application requires Control the start bit through your ladder diagram program Turn it on when you want to send the command message to the remote node Programming methods for start bit control are covered in the discussion on Controlling the Start Bit following Figure 5 15 The module controls certain data table words specified by the programmer in the local station processor
10. 3 3 Chapter 3 Installing Data Highway II Link Cabling Hardware Planning Cabling Configuration Taps and Length of Trunkline 3 4 Terminator At each end of the trunkline you will need a terminator to connect to a trunkline jack of the tap Figure 3 4 Figure 3 4 Terminator Before you install any hardware carefully plan your cabling configuration The general cabling configuration of a Data Highway II link is shown in Figure 3 5 A dropline connects each node interface with its tap Trunkline segments connect between taps A terminator connects to a tap at each end of the link to provide the proper terminating impedance 75 ohms at each end of the link You require a tap for each node of the link Also if you plan to add nodes later provide a tap for each future node during initial installation This will avoid the disruption of adding taps and rerouting the trunkline see Figure 3 5 A trunkline segment between two taps must be a minimum of 30 cable feet For example if your link requires 24 taps the trunkline length is limited to 6 200 cable feet If your link requires only 5 taps the trunkline length can be up to 7 625 cable feet Figure 3 6 shows the relationship of trunkline length to the number of nodes using local taps You can calculate the trunkline length limit for cable with the formula Trunkline Limit Cable Feet 8 000 No of Local Taps x 75 Chapter 3 Installing Data Highway
11. To turn on the start bit the program examines application conditions These may include input output device data values or other information from the controlled process For the most part an application condition used to initiate a command is one of these general types ON or OFF Status of a Bit Transition of a Bit Timed Condition 5 26 Chapter 5 Programming the Local Host To turn off the start bit the program examines the response from the PLC 2 DHII interface This response may be one of the following Done Bit Remote Fault Bit Local Fault Bit Next we describe commonly used forms of start bit control Each discussion concerns a different method for initiating command execution All examples show how the program uses both done and fault bits to turn off the start bit An important assumption underlies the examples outlined in the ensuing discussions and shown in Figure 5 16 through Figure 5 19 The assumption is that the program should automatically retry transmission of a command in the event of a fault Only the done bit terminates attempts at command execution A local or remote fault bit response causes the program to re initiate command execution Do not confuse this type of programmed retry with the retry procedure of the PLC 2 DHII interface Transparent to your programming the PLC 2 DHII interface automatically attempts three retries of a message before it sets a fault bit Programmed retry has dis
12. Where necessary branch start and a branch end may be used to fit these elements into the display area of the programming terminal For practical reasons do not exceed this display area Multiple rungs of this type can be used as necessary but each rung needs its own start bit 5 10 Chapter 5 Programming the Local Host Figure 5 7 Bit Command Format Remote Station Start Bit Area may contain any legal combination of these instructions EEE FFF GGG 027 4E uod E de iit EE FF GG NS 07 Branch End Command HHH M JJJ Code If Needed d Branch Start l M If Needed Legend J E Turn ON the Addressed Bit at the Remote Station Turn OFF the Addressed Bit at the Remote Station Remote Station Addresses In the preceding figures Figure 5 1 and Figure 5 3 through Figure 5 7 to specify the remote station we showed you EXAMINE ON elements where the word address designated the node However in some cases you may need to specify not only the node but the link as well In other cases you may need to specify the user also A case in point is the asynchronous device DHII interface that has two channels to support two users of the highway The full remote station address is shown below You can use it wherever you use a station address in any of the rungs Remote Station Address LLL NNN UUU al Link Node User 5 11 Chapter 5 Programming the Local Host
13. grouped according to the error code type Link Layer Error Codes Time Critical Error Codes Local Errors Remote Errors KP2 Prescan Error Codes Link Layer 11 MAC board memory buffer is full at remote interface 12 Remote interface is off line 13 Remote interface cannot accept message possibly wrong mode 15 Memory buffer is full on host board at remote interface 1A Local interface not in logical ring 1C Two node interfaces identified by same node address 1D Ring has a second token 1F Destination node specified is not on the link 22 Address for destination node is illegal 26 Data path between MAC and host boards temporarily blocked at local interface 2E Message buffer is full in local interface 2F Too many messages being sent to the local interface FF Reset of application layer FE TNS value in reply does not match value in command FD Reply came from wrong node FC Remote reply timer or remote TC reply timer in the local interface timed out FB Link field value not legal FA Link field value not legal F9 Illegal SEL field value F8 Remote interface set to wrong communication mode for this type of message F7 User field value not proper 1 or 2 for selecting a KFL channel B 1 Appendix B Error Codes Time Critical B1 Host device at remote node has faulted B2 Memory address specified doesn t exist in host device at remote node B3 Data in write co
14. B must not touch t IB o a conducti BU Gr surface Esq S Bon S Dropline Chapter Summary Once you have installed the Data Highway II link cabling hardware you are ready to install the node interfaces 3 16 Chapter Objectives Planning the Layout Installing the PLC 2 DHII Interface This chapter presents procedures for Planning the Layout Mounting the PLC 2 DHII Interface Setting Switches Connecting Communication Cables Connecting Power Read this chapter before you install the KP2 interface module We provide steps for you to follow for proper installation Failure to follow the steps provided may result in equipment damage The maximum distance between components is limited by cable length You must plan the layout so that the PLC 2 DHII interface is within 10 cable feet of the PLC 2 family processor The minimum component spacing is limited by heat dissipation considerations The temperature of the air must not exceed 609C 1409F at any point immediately below any chassis PLC 2 DHII Interface processor chassis I O chassis power supply The failure rate of the semiconductor devices may increase significantly if the temperature is raised above 60 C Furthermore a significant decrease in the failure rate of the semiconductor devices can be expected for every degree below 609C that
15. Cables within the conduit should be loosely arranged The tap has a metal shell which electrically connects to the outer conductor of the coaxial cable Therefore the mounting base of the tap is made of plastic to insulate the metal shell from ground However the cap for the dropline jack hangs down on a chain Be sure to mount the tap so that the cap and its chain hang freely without touching a conductive surface If the metal shell cap or chain touches a conductive surface the reliability of the link could be significantly reduced If you do not have a node interface to connect to the tap place the cap over the dropline jack on the front of the tap Figure 3 12 In that case store the dropline so that it will be available later when you install a node interface Installing the Trunkline Chapter 3 Installing Data Highway II Link Cabling Hardware Figure 3 12 Cap on Dropline Jack of Tap without a Node Interface 1 Put cap on dropline jack Because the trunkline can vary greatly from one Data Highway II configuration to the next you have to construct your own trunkline The trunkline actually consists of a number of cable segments Each segment connects between the taps of two neighboring nodes on the trunkline Figure 3 5 Three major tasks are required in constructing the trunkline Cutting the cable into segments of appropriate length A
16. Purpose audience vocabulary and organization for manual Introducing the PLC 2 DHII Interface Overview of PLC 2 DHII interface its function application and messages it sends and receives 3 Installing Data Highway II Link Cabling Installing taps droplines and Hardware trunklines for Data Highway II link Installing PLC 2 DHII Interface Installing PLC 2 DHII interface and connecting it to a PLC 2 family processor Programming Local Host Programming communication zone rungs needed in PLC 2 family processor Operation and Troubleshooting Operating and troubleshooting your KP2 interface This chapter told you about this manual In the next chapter we introduce the Data Highway II PLC 2 Family Interface Cat No 1779 KP2 KP2R Chapter Objectives What Is the PLC 2 DHII Interface Introducing the PLC 2 DHII Interface This chapter gives you an overview of the 1779 KP2 interface its function its application in a communication network and the types of messages it sends and receives The PLC 2 DHII interface is a standalone unit consisting of One Stationary Frame One Removable Frame One Power Supply Board Cat No 1779 PH2 One PLC 2 Host Board Cat No 1779 JP2 One Media Access Controller Board Cat No 1779 JMA A redundant PLC 2 DHII interface has a redundant media access controller board Cat No 1779 JMAR instead of a Media Access Controller board The stationary frame mounts
17. Tel 1 414 382 2000 Fax 1 414 382 4444 Publication 1779 6 5 3 January 1987 PN 955100 47 Copyright 1987 Allen Bradley Company Inc Printed in USA
18. a cable being pulled out of its plug secure each cable in place with some form of strain relief device Installing Droplines Chapter 3 Installing Data Highway II Link Cabling Hardware Figure 3 15 Trunkline Segments Connected to a Tap that Is Not at an End of the Link Trunkline Trunkline Segment Segment d Tap After mounting the node interface Chapter 4 pull the node interface out to the switch setting position before connecting the tap to the node interface This is the only way to be sure that the dropline will have enough slack in the switch setting position Remember the 3 inch minimum bend radius Plug the right angle plug of the dropline into the jack labeled DATA HWY II PORT on the node interface Then plug the other end of the dropline into the jack on the front of the tap Figure 3 16 Chapter 3 Installing Data Highway II Link Cabling Hardware Figure 3 16 Connecting the Dropline from the Node Interface to the Tap o 20 p L o H a Interface 8 Tap 5 8 Cap and m Chain
19. be sure that the dropline will have enough slack in the switch setting position Remember the 3 inch minimum bend radius Plug the right angle plug of the dropline into the jack labeled DATA HWY II PORT on the PLC 2 DHII interface Then plug the other end of the dropline into the jack on the front of the tap Figure 4 11 Figure 4 11 Connection to a Tap OQ RIO A 2 lol s a ee rp iz Industrial k Terminal EU e a ee E d me N 5 o S 8 o m MNA pon 2 7 S E Bon pce Pr PLC Processor g S E Dropline Tap Connecting Power and Ground Chapter 4 Installing the PLC 2 DHII Interface To connect the PLC 2 DHII interface to power and ground follow these steps 1 Pull the removable frame out to the switch setting position This exposes the power selection switch on the right side of the removable frame assembly Figure 4 12 Figure 4 12 Power Selection Switch 115V Y If you connect iibV AC input power slide the switch up If you connect 230V AC input power slide the switch down 10912 1 2 Set the power selection switch to correspond to the l
20. by the PLC 2 DHII interface to indicate that a command has been completed Start Bit turned OFF by the program Done Bit set OFF by the PLC 2 DHII interface after it senses that the Start Bit has been set OFF OOG Chapter 5 Programming the Local Host Table 5 A Start Done Bit Status 0 0 Idle 1 0 Command initiated or in progress 1 1 Command reply operation complete 0 1 The processor based on the program acknowledges completion of the command reply operation transient condition since the KP2 interface turns the done bit OFF in its next scan Faulted Operation Certain fault conditions can prevent normal reception and execution of commands by the remote nodes To indicate the source of such fault conditions the PLC 2 DHII interface controls remote and local fault bits at the host processor In general the local fault bit indicates that the intended receiving station is unable to receive and acknowledge a command message addressed to it The remote fault bit on the other hand indicates that the intended remote node interface has received the command message but is unable to execute the command at the host processor of the remote node For a summary of the distinction between these fault types refer to Figure 5 12 The timing relationship of these fault bits in command execution is shown in Figure 5 15 In this example the command initiated at the setting of the start bit cannot be
21. command each time a condition changes state Figure 5 18 shows example rungs for this type of command initiation In this example a storage bit called the transition bit is manipulated to control the sending of the command This bit is latched whenever a transition of Input 11111 is detected unlatched only when the done bit is set ON A compare bit 01111 in this example is used to manipulate the transition bit In Rung 2 the compare bit is controlled to match the ON OFF status of the input Because the input and the compare bits are programmed to have matching states both ON or both OFF the conditions of Rung 1 can be true only when the input has just changed from ON to OFF or from OFF to ON Thus Rung 1 conditions set up a one shot true only long enough to latch the transition bit Note that these rung conditions are false as soon as the processor scans Rung 2 The order of these rungs is important for this reason With the transition bit latched the start bit in turn is turned on in Rung 3 This initiates the command In normal operation the done bit unlatches the transition bit in Rung 4 In faulted operation however Rung 3 repeatedly retries the command in much the same manner as in the example of Figure 5 16 The start bit and done bit handshaking is accomplished by the EXAMINE OFF done bit in Rung 3 5 29 Chapter 5 Programming the Local Host Figure 5 18 Transition Initiated Com
22. executed due to some fault condition The module detecting this fault condition sets either a local or remote fault bit Recall that the start bit is program controlled The remote local fault bits meanwhile are controlled by the KP2 interface You must keep this relationship in mind when planning start bit control and fault bit monitoring in the ladder diagram program Note from Figure 5 15 that the fault bit once on remains on until your program turns off the start bit Only after it has detected that the program controlled start bit is off does the PLC 2 DHII interface then turn off the fault bit Note also that the done bit is not set on in the event of a fault condition 5 25 Chapter 5 Programming the Local Host Figure 5 15 Start Fault Bit Timing Faulted Operation x e Start Bit ore Z Command PLC 2 DHII Response Interface Scan or Loci ON D YY TTL Fault Bit OFF VIALLA Done Bit ON OFF LEGEND Start Bit turned ON by the program Done Bit set ON by the PLC 2 DHII interface to indicate that a command has been completed Start Bit turned OFF by the program Done Bit set OFF by the PLC 2 DHII interface after it senses that the Start Bit has been set OFF 9 9 9 Controlling the Start Bit Your program controls the start bit setting it on to initiate command execution turning it off after command completion or after a fault is detected
23. first goes through a reset cycle and a 15 second self diagnostic test cycle before seeking membership in a logical ring on the Data Highway II link Because each of the other switch positions causes the interface to reset the node seeks membership in a logical ring when you switch into the RUN position In the momentary RESET position the interface goes through a reset cycle and a 15 second self diagnostic test cycle If this node is not in a logical ring because you pressed the EXIT REQUEST switch resetting the interface causes it to seek membership in the logical ring again Operating the KP2 Interface After installing the 1779 KP2 interface as we described in Chapter 4 switch to the TEST position before you power up the interface for the first time This provides the most extensive test cycle to ensure that the interface is operating properly before you attempt to communicate through it Each test cycle takes approximately 50 seconds If you leave the switch in the TEST position the interface will continuously execute the test cycle Leave the switch in the TEST position at least 15 seconds When you switch to the RUN position the interface will continue through the end of the current test cycle if no faults are detected the NODE PASS indicator turns on green At this point the interface is in the RUN position In the RUN position Initially the PORT READY indicator turns green and the IN RING SEEKING MEM indicator turns yellow to i
24. have bridges to join Data Highway II links However we have designed the Data Highway II network with the flexibility to accommodate bridges at a later date Any discussion of bridges in this manual is only in regard to future product development You can join two Data Highway II links with a bridge The bridge becomes a node on each of the two links The two Data Highway II links and their host interface links combine to form a single Data Highway II network Figure 2 5 Actually you can configure a Data Highway II network of many Data Highway II links joined together with bridges A node can address up to 254 links The advantage of configuring a network of several small links instead of one large link is that separate message transmission can take place within each of the links all at the same time Each link has its own token which it passes around to its nodes For example in Figure 2 5 the computer could send a message to the PLC 3 processor at the same time that the PLC 2 30 processor is sending a message to the PLC 2 15 processor However a message from a node on one link to a node on another link would use up message transmission time in both links By configuring links within a network so that most messages do not cross from one link to another you can improve the performance of the network Communication is always initiated by a node transmitting a command message Only the node holding the token can initiate communication b
25. in node start up when program errors are detected in the communication zone By viewing the header rung of the communication zone you can examine a displayed error code and the least significant digit of the counter in this word The header rung is described earlier in the discussion about Header Delimiter Rungs In some instances however it may be preferable to display the 2 digit error code using a 7 segment hexadecimal display controlled from output modules of the controller This 7 segment display mounted at an operator s station can be a useful troubleshooting aid for quickly locating fault conditions Some hexadecimal codes will not display correctly on 7 segment BCD displays In this discussion you will read about the support programming for commands at the host processor This programming uses the start done and remote local fault bits to initiate and monitor command execution Using these recommended techniques you coordinate communication zone programming with your application program Start Done Fault Bit Timing The start bit that initiates a command is program controlled the done bit which indicates command completion is controlled by the KP2 interface The timing relationship of start and done bits is important when you initiate and terminate commands The following describes this relationship in normal operation and the automatic responses which result from faulted operation NOTE The KP2 interface s sca
26. memory in the host at a remote node For a write block command you can specify either Write with No Reply Write with Reply Write Verified If the local node transmits a command to write with no reply the remote node never transmits a reply Figure 2 6 If the local node transmits a command to write with reply when the remote node interface receives the token it transmits a reply message to indicate whether it was able to successfully write into the host s memory Figure 2 7 2 11 Chapter 2 Introducing the PLC 2 DHII Interface 2 12 Figure 2 6 Write with No Reply Message Transfer Command Message Block of data to write into host at Node 2 meee AP p ap p p gt Noe Figure 2 7 Write with Reply Message Transfer Command Message Block of data to write into host at Node 2 Noce He p gt p p Node Reply Message Status of whether the write was successful i If the local node host transmits a command to write verified the local node interface first transmits a command to write with reply When the remote node interface receives the token it transmits a reply message to indicate whether it was able to successfully write into the host s memory When the local node interface receives the token again it then automatically transmits a command to read that same block of data After the remote node interface writes th
27. multiple branches This rung lists the remote nodes which have access to write into specific blocks of data table as follows Node 020 can access Words 070 076 Node 017 can access Words 063 065 and Word 022 Node 010 can access Words 060 064 As shown in Figure 5 4 you can identify a particular remote node in more than one memory access branch Also you can assign two or more nodes to have access to the same block of words For practical reasons do not exceed the display area of the programming terminal when entering these rungs More than one memory access rung can be programmed if needed Should you require multiple memory access rungs you can enter them in any order in the communication zone Grouping memory access rungs together promotes ease of programming Chapter 5 Programming the Local Host Figure 5 4 Typical Memory Access Rung 020 070 076 017 022 022 027 Fer Her mema 00 00 07 017 063 065 010 060 064 eHe Heal 00 00 Command Rungs The command rungs direct the PLC 2 DHII interface to send command messages to remote nodes Each command rung lists the type of command and the bits or block of words affected You initiate a command message through the ladder diagram program A command rung to read or update an immediate access block is significantly different from all other general command rungs However the first element on each command rung must be an EXAMINE ON instruc
28. observing the following precautions 1 Press the EXIT REQUEST switch 2 When the EXIT COMPLETE indicator goes on turn off the AC POWER switch 3 Disconnect the AC power at the source disconnect switch or circuit breaker WARNING Always disconnect AC power at the source before attempting to remove connections at the interface power terminals If you fail to heed this warning you will receive an electrical shock from touching the terminals 4 Remove the AC power connections from L1 and L2 N and the ground connection from the GND post on the interface 5 Disconnect the green conductor that grounds the stationary frame to the ground post on the removable frame Figure 6 2 Chapter 6 Operation and Troubleshooting Figure 6 2 Green Conductor Connecting the Stationary Frame to the Ground Post on the Removable Frame 115V AC 230V AC INTERNALLY SWITCH SELECTABLE L2 N cd Q r8 L1 Green Grounding Conductor 6 Disconnect the cables from the front of the interface 7 Loosen the four thumbscrews on the front of interface 8 While holding the removable frame at the top and bottom slide it out to the switch setting position then lift it up an inch and then out away from the stationary frame 9 Locate the ribbon cables that connect the boards at the back Figure 6 3 6 7 Ch
29. on the PLC 2 DHII interface This number should be an octal number from 010 to 077 or from 110 to 376 Again 0 to 7 and 100 to 107 cannot be entered by the Industrial Terminal and 377 is an invalid node designation 5 3 Chapter 5 Programming the Local Host 5 4 Figure 5 2 Header Rung Address of Error Word Supervisory Local Timeout Node Preset Code Time Critical Timeout Preset i Code 022 077 030 011 027 1 eaa C L 00 07 Optionally a single GET will supply a single timeout for both supervisory and time critical The address in the three GET elements in the header rung specify from left to right The Address of The Error Word The Supervisory Timeout Preset Code The Time Critical Timeout Preset Code Select any available word in the data table as the error word The PLC 2 DHII interface will write error codes into the word you select refer to the Error Word discussion preceding Figure 5 12 The timeout preset code gives a programmed timeout interval for command completion Based on the three digit value entered for the address in these GET instructions the PLC 2 DHII interface monitors command execution for all commands sent from the local node The significance of this preset code its computation and timeout considerations are described in the discussion about Timeout Preset Value refer to Figure 5 23 These are two timeouts If you use two GET instructions the first timeout is for
30. protecting the coaxial cable from electrical interference Ifthe cable must cross power feed lines it should do so only at right angles Keep the cable at least 1 foot from 120V AC power lines 2 feet from 240V AC power lines and 3 feet from power lines of 480V AC or more Keep the cable at least 3 feet from any electric motors transformers rectifiers generators arc welders induction furnaces or sources of microwave radiation 3 9 Chapter 3 Installing Data Highway II Link Cabling Hardware Installing Taps 3 10 Conduits Conduits provide protection from physical damage as well as an additional layer of protection from electrical interference for a coaxial cable Route the trunkline cable through conduit for the first 20 feet above the enclosure Where you route the coaxial cable through conduits follow these additional recommendations Use ferromagnetic conduit near the greatest sources of electrical interference You can use aluminum conduit in non critical areas Couple between aluminum and ferromagnetic conduits with plastic connectors Make an electrical connection around the plastic connector to hold both sections of the conduit at the same potential The entire length of the conduit should be grounded Ground the conduit by attaching it to the steel structure of the building Do not let the conduit touch the tap or the plug on the cable Third conduit should only contain serial communication cables
31. status for those program controlled bits This would occur only if the program altered the state of a bit while the PLC 2 DHII interface was executing a received write bit command 5 41 Chapter 5 Programming the Local Host Chapter Summary 5 42 Therefore when using the write bit command address only bits within a byte which are set aside exclusively for control by these commands Note that this byte restriction for write bit commands does not apply to any but the PLC 2 family processors After you have generated a program at each host to communicate with the other nodes you can begin to start up and operate the Data Highway II network Chapter Objectives Indicators Operation and Troubleshooting This chapter provides the following A description of the function of each LED indicator and switch on the front panel for operating the 1779 KP2 interface Procedures for operating the 1779 KP2 interface Procedures for narrowing down the source of the problem when a problem occurs within the local node Procedures for replacing a faulty board in the 1779 KP2 interface The 1779 KP2 interface has 21 LED indicators on its front panel The 1779 KP2R interface has the same indicators plus the redundant warning indicator and the port ready signal quality and tap fail indicators for the redundant port These indicators provide you with the following diagnostic information Figure 6 1 6 1 Chapter 6 Ope
32. supervisory The second GET is for time critical The timeout preset for time critical can be smaller while the supervisory can be generally larger If you use only one timeout it applies to both supervisory and time critical Refer to the discussion Programming Preset Code and Table 5 B which lists timeout preset codes Chapter 5 Programming the Local Host Memory Access Rungs Memory access rungs define blocks of data table words which can be accessed with protected write commands from the remote node you specify Protected write commands received from the specified remote node may access only those blocks of local data table words listed in memory access rungs However with no memory access rungs the local node will accept protected write commands from any remote node to access any part of the data table WARNING Unprotected write commands override any memory access rungs Use them with discretion because writes to unauthorized data table areas can result in damage to equipment and personnel Don t forget that to allow access to data table write commands from any remote node you must set the accept writes to data table switch to ON Chapter 4 A memory access rung is composed of one or more memory access branches as shown in Figure 5 3 In the memory access branch format a branch start precedes a group of elements The EXAMINE ON and GET elements in the memory access branch specify the following The word address i
33. switch off wait 20 seconds and turn the AC POWER switch on If still off try replacing each of the three boards until you find the faulted one ON If on press EXIT REQUEST switch to RESET momentarily and then to run then proceed to Step 3 Check the HOST FAULT indicator ON If on replace the host board OFF If off proceed to Step 4 Check the MAC FAULT indicator ON If on replace the MAC board OFF If off proceed to Step 5 Check the DUP ADDR indicator ON If on press EXIT REQUEST set a unique link address for the node then switch to RESET momentarily and then to RUN OFF If off proceed to Step 6 Check the IN RING SEEKING MEM indicator YEL If yellow check the cabling on the Data Highway II link GR If green check the cabling to the host device Chapter 6 Operation and Troubleshooting Figure 6 6 Troubleshooting Flowchart Problem Suspected Check AC POWER Switch Fuse AC Power Source nterlock Switch Step 1 Power Supply Board Set the AC power switch to OFF wait 20 seconds then set the AC power switch to ON If the indicator is still OFF try replacing each of the three boards until you find the faulted one Step 2 Press EXIT REQUEST Switch to RESET momentarily and then to RUN Step 3 Replace host board Step 4 Replace MAC board Press EXIT REQUEST Step 5 Se
34. the ambient temperature can be kept The temperature will tend to be higher toward the top of the enclosure Factors that determine the level at which the temperature will be 609C include The Size of the Enclosure The Power Dissipation within the Enclosure The Temperature of the Air Surrounding the Enclosure Power dissipation includes not only the power dissipated through the power supplies for the PLC 2 DHII interface the processor chassis and I O chassis but also the user supplied power dissipated through the input and output circuits 4 1 Chapter 4 Installing the PLC 2 DHII Interface To allow necessary air flow for cooling of components refer to Figure 4 1 and follow these rules Do not mount an I O chassis above a processor chassis Provide 6 inches minimum vertical separation between chassis and to top and bottom of the enclosure with no chassis mounted above the 60 C air temperature level Figure 4 1 Provide minimum horizontal separation between chassis and to enclosure sides Leave any excess space at the top of the enclosure where the temperature is highest Mount wiring ducts taps and terminal strips no closer than two inches from any chassis 4 2 Chapter 4 Installing the PLC 2 DHII Interface Figure 4 1 Minimum Spacing for Necessary Air Flow for Cooling
35. EE Invalid link ID either 0 or more than 255 B 3 N 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 MA Argentina Australia e Austria e Bahrain e Belgium Brazil e Bulgaria e Canada Chile e China PRC Colombia Costa Rica Croatia e Cyprus e Czech Republic e Denmark Ecuador e Egypt El Salvador Finland France Germany Greece e Guatemala Honduras e Hong Kong Hungary Iceland e India Indonesia e Ireland e Israel Italy e Jamaica Japan e Jordan Korea Kuwait e Lebanon e Malaysia Mexico e Netherlands New Zealand e Norway Pakistan e Peru e Philippines e Poland e Portugal Puerto Rico Qatar e Romania Russia CIS e Saudi Arabia e Singapore Slovakia Slovenia e South Africa Republic e Spain e Sweden e Switzerland e Taiwan e Thailand Turkey United Arab Emirates e United Kingdom e United States Uruguay Venezuela e Yugoslavia Allen Bradley Headquarters 1201 South Second Street Milwaukee WI 53204 USA
36. Exposed power terminals could cause you to receive a dangerous electrical shock 10 On the front of the interface set the AC POWER switch to OFF Figure 4 13 11 Close the main disconnect switch to allow AC power into the enclosure 12 On the front of the interface set the AC POWER switch to ON Figure 4 13 Figure 4 13 Power and Ground Connections Power Distribution Chapter 4 Installing the PLC 2 DHII Interface ON 9 AC POWER OFF ruse SLOW BLOW 2A 250V 115V AC 230V AC INTERNALLY SWITCH SELECTABLE L Connect L1 to high side of transformer L1 L2 N _ Connect L2 N to low side of transformer Connect GND post to central ground bus Connect a separate transformer between the AC power source and the interface power supply to provide DC isolation from other equipment Connect the transformer primary to the AC source connect the high side of the transformer secondary to the L1 terminal of the power supply connect the low side of the transformer secondary to the L2 N terminal of the power supply The power consumed by the PLC 2 DHII interface is 50 Multiply the power requirements of the Allen Bradley power supplies by 3 and add all other power requirements input circuits output circuits to determine the required rating of the transformer The power requirements must ta
37. II Link Cabling Hardware Figure 3 5 Cabling Configuration of a Data Highway II Link Trunkline QE a Terminator o ET Ef Lt i j C8 I t 1 I l E E o B e Dropline Node Interface Tap Figure 3 6 Relationship between Trunkline Length and Number of Nodes with Local Taps 10K 8K eK Length of Trunkline in Feet 4K 2K 20 40 60 80 100 120 Number of Nodes with Local Taps 3 5 Chapter 3 Installing Data Highway II Link Cabling Hardware Bend Radius of Cables If you bend a coaxial cable sharper than the recommended minimum bend radius you may decrease the reliability of the link Plan your trunkline cable routing so that the cable will have no sharper bend than a minimum 6 inch bend radius Figure 3 7 Figure 3 7 Trunkline Cable Showing Minimum Bend Radius 6 inch TZT Plan your dropline cable routing so that the cable will have no sharper bend than a minimum 3 inch bend radius Figure 3 8 Figure 3 8 Dropline Cable Showing Mi
38. PLC 2 family processor to communicate across the Data Highway II Chapter Objectives Communication Zone Programming the Local Host In this chapter you will read about how to generate a ladder diagram program for a PLC 2 family processor local host to communicate through the KP2 interface to the host of a remote node The generation of commands is discussed as if transmitted to the PLC 2 family processor at a remote node If another type of PLC processor is at the remote node refer to the manual for the node interface of that PLC processor for information on that processor s addressing conventions For a computer and some processors at a remote node to accept commands from this local node it must have a file at the remote node host to simulate a PLC 2 family data table A Data Highway II network allows access to the memory of each remote node This means that data table information at any operating PLC processor can be transmitted to another PLC processor or to a computer and used by the other node to control its own part of an operation The communication zone is a set of rungs with a well defined beginning header rung and a well defined ending delimiter rung that you enter into your control program The rungs between the header and delimiter tell your highway interface what messages to generate and what messages to accept while this process is running Figure 5 1 shows a simple communication zone including each function ty
39. PLY 07 Unused 17 Unused Whereas Protected means that when a command with this quality is received it is checked against the memory access rungs Unprotected means that a command with this quality overrides any memory access rungs put in to stop it As in Data Highway they should be used with discretion Memory access does not apply to READ commands so the READ BLOCK is neither protected nor unprotected Note that Codes 05 and 06 are different from 15 and 16 while other commands are symmetrical They are enhanced WRITE commands A VERIFIED command is issued for supervisory while a NO REPLY command is issued for time critical There is no supervisory NO REPLY nor is there a time critical VERIFIED Should you receive Error Code E9 UNKNOWN COMMAND CODE error codes are listed in both this chapter and Chapter 6 it means that you may have used a command code that is not yet implemented These currently include 03 04 05 06 13 14 and unused Command Codes 07 and 17 5 8 Chapter 5 Programming the Local Host General Block Command Format Use the format shown in Figure 5 6 when you enter a command code specifying any of the following commands Read Block Protected Write Block with No Reply Protected Write Block with Reply Protected Write Block Verified Unprotected Write This format uses three GET elements Use the address in the first GET element to specify a remote node data table word The spe
40. Programming the Local Host 5 38 If it is necessary to use some value other than those provided in Table 5 B compute the 3 digit timeout preset code with the following steps 1 Select a timeout preset interval This interval must be larger than 1 2 second at intervals of 1 2 second For the purpose of computing the code label this number S Example Desired Interval 4 5 S 2 Compute a decimal number using the desired interval of Step 1 in the following formula 5 2 8 Example 4 5 2 8 9 8 17 3 Convert this value to an octal value Example 1719 2 21g For a description of decimal to octal conversion refer to the Programming and Operation Manual of the controller being used User Programmed Timeout The automatic timeout of the PLC 2 DHII interface is a backup function This automatic monitoring routine continuously checks PLC 2 DHII interface interaction with other nodes timing the execution of commands This automatic timeout does not check PLC 2 DHII interface communication with its host processor For a backup check on interface host communication you might use an optionally programmed ON delay timer instruction TON With proper interface host communication the PLC 2 DHII interface sets either a done bit or a remote or local fault bit as a response to a command However in the event of faulted interface host communication or faulted PLC 2 DHII interface operation a response bit might not be set Instea
41. Rung to designate communication zone header if a communication zone is needed Rungs to define memory access as needed Rungs to update immediate access blocks as needed Rungs to read immediate access blocks as needed Rungs to read write blocks as needed Rungs to write bits as needed Rung to delimit the end of the communication zone Figure 5 1 shows the addresses above most GET instructions but not the three digit data value displayed below the GET element This convention is used for clarity since only the GET address is significant when entering your communication zone In entering communication zone rungs you don t need to enter values with the GET instructions Header Delimiter Rungs A minimum communication zone consists of a header rung and a delimiter rung The delimiter rung defines the end of the communication zone This rung must be exactly as shown in Figure 5 1 The unlatch 02707 instruction is interpreted as a special code Word 027 is reserved for special functions such as this and cannot be used for other data table use The header rung defines the start of the communication zone It must consist of an EXAMINE ON element two or three GET elements and a latch 02707 element Figure 5 2 The word address in the EXAMINE ON instruction in the header rung specifies the local node The local node designation must match the three digit number you selected with the link address thumbwheels
42. TIVITY SAT The node has reached the peak of its ability to process messages ACTIVITY NORMAL On Green These three indicators show the relative amount of processing taking place at the interface If all three indicators are on the amount of processing is high if just one indicator is on the amount of processing is low ACTIVE This program interface active light is green when communication path is OK and sending and receiving from Industrial Terminal programming device is normal COMM ERROR On Red A program interface communication error exists The Industrial Terminal has broken communication to resynchronize PROG ERR On Red There is a processor program error no communication zone or an error exists in the communication rung PROC ERR On Red This indicates a processor error The PLC 2 has interrupted communication to resynchronize MAC FAULT The MAC board has 1 failed the self diagnostic test 2 faulted while in operation or 3 a duplicate address exists MAC TEST The MAC board is performing a self diagnostic test EXIT COMPLETE On Yellow This node has left the logical ring of the Data Highway II link IN RING This node is a member of the logical ring on the Data Highway II link SEEKING MEM This node is trying to become a member of the logical ring or trying to build a logical ring in the case that a ring does not already exist p This node is not a member of a logical ring and is not seeking membership places this
43. These data table words indicate the status of command execution and provide various types of diagnostic information for start up and troubleshooting These words are One or more pairs of adjacent words for start done and remote local fault storage An error word Chapter 5 Programming the Local Host Refer to Figure 5 10 You specify the addresses of these status words when entering the communication zone rungs A pair of start done and remote local fault words is defined by the selection of the start bit in a command rung You specify the error code storage word in the header rung Figure 5 10 User Selected Status Words IO Local Station Data Table uy 0 8 Start Done Word Remote Local Fault Word E o o o Error Word 9 B e 8 rc NOTE Start Done and Remote Local Fault words un SAL cnp e adjacent Use one pair for each group of u to 8 commands god Q CAT NO 1779 KP2 PLC 2 DHII INTERFACE Any accessible data table words may be used as status words in the station processor Start Done Word The start done word is the first of a pair of adjacent status words for module use This word stores a start bit and correspondin
44. ace to monitor command execution time without using timer TON instructions in the program Figure 5 23 shows the significance of the timeout preset interval From the time the start bit is set ON the PLC 2 DHII interface must set either a done bit or a remote or local fault bit within the timeout preset interval Should the PLC 2 DHII interface detect no done or fault bit response within the preset interval a fault is assumed As a response to this type of timeout situation the PLC 2 DHII interface turns on the local fault bit and enters the values B8 or 37 in the lower byte of the error word defined by the header rung Figure 5 23 Timeout Preset Significance Header Rung Code Representation Haa Lo XBF Optional GET Code BF Entered if Timeout Occurs Time Preset Interval Within This Period Done or Fault Bit Expected 2222222 Start Bit ON OFF Done Bit ON OFF Remote ON Fault Bit OFF Fault ME Local ON et if Timeout Occurs Fault Bit OFF 2 Time Timeout preset monitoring is intended as a backup for the other communication monitoring functions of the PLC 2 DHII interface It is designed to signal any condition where the PLC 2 DHII interface has not completed its communication with another node or detected some fault condition within a short time Because this timer is primarily intended as a backup for some local fault type of situation its preset value is not cri
45. against the shoulder of the plug body 10 Put the crimping tool over the plug sleeve and as close to the plug body shoulder as possible Crimp the sleeve onto the plug body 3 12 Chapter 3 Installing Data Highway II Link Cabling Hardware Figure 3 13 Attaching the Cable Plugs a Coaxial Cable Steps 1 through 4 Steps 5 and 6 0 7 in 0 3 in 0 21 Plug Sleeve Plug Pin i Braid A Steps 7 and 8 Plug Body Steps 9 and 10 EN Crimped Sleeve i 3 13 Chapter 3 Installing Data Highway II Link Cabling Hardware Plugging into the Tap At the tap at each of the two physical ends of the link plug the trunkline segment into one trunkline jack of the tap Plug a terminator into the other trunkline jack of the tap Figure 3 14 Figure 3 14 Terminator and Trunkline Segment Connected to a Tap at One End of the Link Trunkline C Segment Terminator EN Tap A Beo Dropline At each tap other than at the end of the link plug the two trunkline segments into the two trunkline jacks on the tap Figure 3 15 To guard against the minimum bend radius being violated or
46. ands to read immediate access blocks An immediate access update rung consists of an EXAMINE ON element two GET elements an EXAMINE OFF element and an Output Energize Address 02707 element Figure 5 8 5 13 Chapter 5 Programming the Local Host Figure 5 8 Immediate Access Update Rung Immediate Access Block Boundaries in Local Host Data Table 21 Words Max Starting Ending Start 1 Address x Local Node 024 200 217 052 027 aa F 10 00 07 M Immediate Access Block Number The EXAMINE ON GET and EXAMINE OFF elements in the immediate access rung specify the following The bit address of the EXAMINE ON instruction specifies the start bit that controls when the PLC 2 DHII interface reads the immediate access block defined by the rung The word address in the first GET element specifies the starting address of the immediate access block The word address in the second GET element specifies the ending address of the immediate block The immediate access block must not exceed 21 words The word address in the EXAMINE OFF element must specify the local node which must match the link address thumbwheel setting The bit pointer in the EXAMINE OFF element specifies which one of 16 possible immediate access blocks is defined by this rung The immediate access update rung of Figure 5 8 is controlled by Start Bit 02410 High Byte 10 17 and defines the block of words from 200 through 217 which will be us
47. apter 6 Operation and Troubleshooting Figure 6 3 Rear View of the Removable Frame Assembly Shield Ribbon Cables ZN Power Supply MAC Host Board Board Board 12617A 10 On the top two ribbon cable connectors locate the levers for locking and ejecting the connectors Figure 6 4 6 8 Chapter 6 Operation and Troubleshooting Figure 6 4 Locking Ejecting Levers on Connectors oN am Levers SS 11 Push the lever apart with your thumbs to eject the cable from the connector on the board 12 Remove all three ribbon cables components To help prevent damage to circuit board components always transport circuit boards in anti static material When installing or removing circuit boards observe all precautions to help prevent electrostatic damage CAUTION Electrostatic discharge can damage circuit board 6 9 Chapter 6 Operation and Troubleshooting 6 10 13 14 15 16 17 18 19 Remove five screws to remove the power supply board Remove five screws to remove the host board Remove power supply and host board screws to remove the MAC board With the screws removed you can slide the faulted board straight out the back of the removable frame Replace the faulted board with a spare Replace the mounting screws Reconnect the three ribbon cables to the back of the boards A CAUTION Do not misalign the pins when you connect the b
48. at the end of the chassis Figure 3 10 shows an example of a tap mounted below a node interface The trunkline runs straight out through the sidewall of the enclosure Figure 3 10 Local Tap Mounted between a Node Interface Node Interface Trunkline N Ed LETT em eren em oo 000000 Use conduit for 9 the first 20 ft from enclosure Po A 000 E E 3 Gr 7 Woe E Dropline N Figure 3 11 shows an example of taps mounted beside a node interface The trunkline cables run straight out through the top of the enclosure Chapter 3 Installing Data Highway II Link Cabling Hardware Figure 3 11 Local Taps Mounted Beside a Node Interface Use conduit for Trunkline the first 20 ft from enclosure Top of Enclosure Node Interface Tap Sr Bog 7 2 e S Droplines Planning Cable Routing Follow these cable routing recommendations for
49. bit after successful command completion remains ON until Input 11111 goes OFF Recall from Figure 5 14 that the PLC 2 DHII interface holds the done bit ON until after the start bit is turned off Should a fault condition prevent normal execution the rung Figure 5 16 provides a programmed retry of the command as long as Bit 11111 is ON A remote or local fault turns off the start bit The start bit is turned on again after the PLC 2 DHII interface resets the fault bit As Figure 5 15 shows the PLC 2 DHII interface resets a fault bit only after the start bit has been turned off Even though the fault bits are continually reset with this method their usefulness must not be overlooked Monitoring Remote Local Fault Bit outlines a useful method you can use to monitor fault bits and control an output indicator based on fault bit status Chapter 5 Programming the Local Host In some applications it may be useful to send a command continuously between stations You can accomplish this by adding an EXAMINE OFF instruction for the done bit as in Figure 5 17 This would cause the command to be sent continuously as long as Input 11111 remains ON Figure 5 17 Status Initiated Command Sent Continuously Remote Local Input Fault Fault Done Start 111 033 033 032 032 e E 11 12 02 02 12 Transition You can use the transition of an input device from ON to OFF and from OFF to ON to latch the start bit This allows you to send a
50. c command set Remote Programming The PLC 2 DHII interface assists remote programming devices in allowing programmers to edit and monitor user programs from other Data Highway II nodes Remote Command Control Third Party The PLC 2 DHII interface has a special facility to allow other nodes to program them just as if a command had been entered via the rungs in the local PLC This is called a third party request If you consider the ladder rung in the local PLC that says in effect read data from Node 5 to be the first party and in this case Node 5 to be the second party then you will see that if some OTHER node say Node 10 sends a message to the local interface saying read data from Node 5 Node 10 would be a third party Node 10 sends a remote command block and the KP2 generates a message and sends it out just as if it were a local command coming from the local PLC s ladder rung program This is all happening in the background while the KP2 is generating and accepting other commands Chapter 4 shows that if you do not want these remote commands executed you can disable it with a switch Redundant Cabling Chapter 2 Introducing the PLC 2 DHII Interface Station Management The station management commands change network parameters If you install the redundant version of each node interface you can install a second complete cabling system for the Data Highway II link Figure 2 9 In Figure 2 9 we sh
51. cified command operation begins at this address Use the address in the second GET element to define the start and the address in the third GET element to define the end of a block of data table words in the local node host processor This block contains words to be transferred in the write or read operation A time critical message is limited to 18 words when writing to an address less than 177 When you write data to an address greater than 177 you are limited to 17 words for a time critical message This is because two additional bytes are used per addresses over 177 for sending time critical messages However the size of a supervisory message is unlimited In the write block operation a block of data from the local node data table is written to data table words of a remote node The first GET element in the command rung specifies a beginning address at the remote node Data is to be written into this word and succeeding words from the local node data table The second and third GET elements in this type of rung list the starting and ending boundary for the block of words to be sent from the local node data table In the read block operation a block of data is read from a remote node into the local node data table The first GET element in the read block command rung lists the beginning address from which to read data Remote data table words are read in succession beginning with this address This block of words is sent into the block of t
52. ckets When a computer sends a message across the network to a terminal node at the receiving node the interface disassembles the packet and sends only the data field to the terminal Furthermore by issuing a station management command from another station you can establish a logical connection from the terminal to the computer so that if the operator at the terminal Media Access Method Chapter 2 Introducing the PLC 2 DHII Interface enters a data field the interface assembles the data field into the proper packet for the network to deliver the message to the computer The PAD protocol is also useful for devices such as robots which have a fixed protocol In sending a message to a robot a computer could encode the message data field with the protocol that the robot expects At the receiving node the interface disassembles the packet and sends only the data field to the robot Since the computer had encoded the data field the robot sees the protocol that it expects Data Highway Il Link In a Data Highway II link nodes communicate with one another through a physical bus media of coaxial cable The coaxial cable forms the bus connection between the nodes in a trunkline dropline configuration The maximum length permissible for the trunkline depends on the number of nodes the type of cable and the type of tap local tap or extended tap For example with RG 11 type coaxial cable local taps and 52 nodes in a link the trun
53. could be sent back for verification If you use a write verified command you must ensure that the data is not overwritten before it can be sent back for verification 2 13 Chapter 2 Introducing the PLC 2 DHII Interface Message Priority The two categories of message priority are Supervisory Time Critical You determine the priority of messages when you select the command you want to send Most of the commands available have supervisory priority A write verified command always has supervisory priority However certain read and write commands have time critical priority A command to read an immediate access block always has time critical priority Every message except an immediate access block reply has to wait until the node gets the token before it can be transmitted Furthermore token passing occurs on a regularly scheduled basis it is not influenced by the priority of the messages waiting to be transmitted However if two messages are waiting to be transmitted when the node gets the token a time critical message is given priority over supervisory messages at that node Although time critical messages are given priority a minimum percentage of time is regularly set aside for supervisory messages so that they get to their destination regardless of the number of time critical messages to be transmitted You can send time critical messages to other nodes of the same Data Highway II link only However supervisor
54. d the start bit would remain on in this instance until the fault situation was corrected You can use several programming methods to detect such a condition the simplest of these methods uses an ON delay timer Figure 5 24 shows typical rungs that you can program for this purpose Chapter 5 Programming the Local Host Figure 5 24 Typical User Programmed Timeout Start Done 032 032 060 jt TON 12 02 0 1 Remote Fault 032 PR 100 1 000 12 Local Fault 033 02 Output Timed Bit Indicator 060 010 f m 15 02 In the first rung of this figure Timer 060 times the interval between the setting of the start bit for a command and the done local fault or remote fault response of the PLC 2 DHII interface If no response is received within the preset interval of this timer here 10 seconds a fault may be indicated and Bit 06015 is set ON The second rung examines this bit to turn on an annunciator Depending on the individual application you could also use this bit to enable or disable various parts of the program The preset value of this programmed TON instruction is not critical For this type of backup monitoring the programmed preset must exceed the timeout preset interval entered as a code in the header rung Remember that the automatic timeout of the PLC 2 DHII interface gives a local fault response to a command which would indicate normal interface host communication but faulted co
55. e DHII AUX ACCESS connector provides cable connection for future communication requirements Node Interfaces Data Highway Il Network Chapter 2 Introducing the PLC 2 DHII Interface You can use these node interfaces on a Data Highway II link Asynchronous Foreign Device DHII Interface Cat No 1779 KFL Redundant Asynchronous Foreign Device DHII Interface Cat No 1779 KFLR Synchronous Foreign Device DHII Interface Cat No 1779 KFM Redundant Synchronous Foreign Device DHII Interface Cat No 1779 KFMR PLC 2 DHII Interface Cat No 1779 KP2 Redundant PLC 2 DHII Interface Cat No 1779 KP2R PLC 3 DHII Interface Cat No 1779 KP3 Redundant PLC 3 DHII Interface Cat No 1779 KP3R Figure 2 4 Communication Connections _3 3 L o Industrial Terminal PLC 2 Family Bog o S BoR Tap The Data Highway II network is a local area network LAN for the industrial environment that provides peer to peer communication between nodes A Data Highway II network is illustrated in Figure 2 5 2 5 Chapter 2 Introducing the PLC 2 DHII Interface 2 6 Stations Nodes At each node interface you must assign a unique link address to each node of the link A host computer o
56. e data into its host s memory it reads that data from the host s memory When the remote node receives the token the remote node interface then transmits this data back to the local node The local node interface then verifies that the data it received is identical to what it had transmitted Figure 2 8 Chapter 2 Introducing the PLC 2 DHII Interface Figure 2 8 Write Verified Message Transfer Command Message Block of data to write into host at Node 2 Node ne Le Nope Reply Message Status of whether the write was successful ui Command Message Read from host at Node 2 de Reply Message Block of data read from host at Node 2 _ A MH 4 4 lt q lt q A write with no reply takes the least amount of time A write verified takes the most time All messages are transmitted across the Data Highway II link with Manchester encoding and CRC 16 error checking to help ensure data integrity before the interface writes data into its host s memory A write verified command may provide added security in applications where the level of electrical noise is very high However you should be aware that the interface can report a false error in reply to a write verified command For example after the data is written into the remote host s memory it could be overwritten by the program in the host or by another Data Highway II node before it
57. e rung Here then are examples for each case 1 Specifies the link and node User is 1 by default 1 2 Specifies the node and user Link is the local link by default 3 Specifies the link address User is 1 and the link is the pd local link by default Chapter 5 Programming the Local Host For example in Figure 5 3 we show a rung that designates only the remote node on the local link 010 020 023 1 eea 00 If you were to designate a remote station that is on Channel 2 of a KFL interface you would have to add a user designation 010 012 020 023 e ka 00 If you were to designate a remote station that is on another link Link 3 you would have to add a link designation 003 010 012 020 023 00 l Hee You can designate link and user on memory access rungs and supervisory general command rungs You can designate user on time critical general command rungs However you cannot designate link on time critical command rungs because time critical commands can only be sent to nodes on the local link Commands to read immediate access blocks can only designate node These commands cannot designate link or user Immediate Access Update Rung The purpose of immediate access rungs is explained in Chapter 2 Now it is time to program one Each immediate access rung defines a block of words in the local host data table that can be read by any remote node through comm
58. e the sending of a command The PLC 2 DHII interface monitors the status of start bits and transmits the corresponding command when its start bit is set ON 5 18 Chapter 5 Programming the Local Host As it name implies the done bit indicates command completion This bit controlled by the PLC 2 DHII interface is set ON when the execution of a command is completed successfully Each command rung must examine a unique start bit Thus a single pair of start done and remote local fault words has enough bits for up to 8 command rungs Should more command rungs be programmed select additional preferably contiguous word pairs as necessary To optimize memory use and minimize the time required by the PLC 2 DHII interface to scan start bits use all 8 start bits in one word pair before using another start done word For the same reason sequentially group command rungs which use the same start done word You cannot use Word 077 or the last data table word for start done words because the very next words are not part of the data table Remote Local Fault Word As Figure 5 11 shows that selection of the start bit in the program not only causes the PLC 2 DHII interface to control a corresponding done bit in that same word but also causes the PLC 2 DHII interface to control remote and local fault bits in the next data table word A remote fault bit and local fault bit are controlled for each command For a command the position of each of
59. e to buffer received command in memory BB Remote station is in download mode or error in download command or operation not allowed in upload or download mode 92 Destination station fails to respond B 2 Appendix B Error Codes KP2 Prescan Error Codes 00 Message transmission successful 01 PC not responding D2 Switched back to program mode D4 Meaningless rung in communication zone D5 Program ends before a delimiter rung is found D6 Block number in update command missing D7 Too many rungs in communication zone either highwater or number of rungs exceeds 255 D8 Own link address expected in update command D9 Too many read or write block rungs over 200 DA Fault bits in non data table region DB Start bit not Bits 10 17 DC Unrecognized instruction after start bit DD GET for remote address expected DE GET for start address expected DF GET for end address expected E0 Start address gt end address E1 No XIC or XIO instructions in bit write command E2 Too many bit addresses E3 Too many bit write rungs over 50 E4 Unexpected data after a valid command E5 Same start bit used twice E6 Too much for time critical to send E7 Too big for supervisory E8 User dropped start bit before processing done E9 Tried to use reserved code EA Link specified in a time critical command EB Too many time critical rungs maximum is 30 EC Invalid node number
60. ed as Immediate Access Block 00 on this node The PLC 2 DHII interface reads the start bit continually Each time the ladder diagram program turns on the start bit the PLC 2 DHII interface updates this immediate access block to hold that data in anticipation of receiving a command from a remote node to read this immediate access block When it receives a command from a remote node to read an immediate access block it immediately replies with its latest copy of the requested block Chapter 5 Programming the Local Host Should you require multiple immediate access rungs enter them in succession in the communication zone immediately following any memory access rung and before any command rung Read Immediate Access Block Use the format shown in Figure 5 9 when you enter a command rung to specify a command to read an immediate access block This format uses an EXAMINE OFF and two GET elements The word address in the EXAMINE OFF specifies the link address of the remote node Use the bit pointer in the EXAMINE OFF to specify the number of the immediate access blocks to be read from the remote node Use the addresses in the GET elements to define the start and end of a block of data table words to which the immediate access block is sent in the local node host processor The length of this block in the local data table must be the exact length of the block in the remote node Figure 5 9 Command Format for Read Immediate Access Block
61. electricians who install Data Highway II hardware need to read Chapters 1 through 4 of this manual People who program programmable controllers need to read all but Chapter 3 To use the PLC 2 DHII interface you must be able to program and operate a PLC 2 family programmable controller In this manual we assume that you know how to do this If you don t refer to the appropriate manual for the controller you are using Consult our Publication Index Publication 499 for a list of our publications Vocabulary The redundant PLC 2 DHII interface has all of the functions of the PLC 2 DHII interface Therefore when we refer to the PLC 2 DHII interface in this manual it applies to both We only mention the redundant PLC 2 DHII interface in describing a difference When referring to an Allen Bradley programmable controller in this manual we use the Allen Bradley registered trademark PLC programmable controllers Some node interfaces have the function of interfacing with an intelligent foreign device such as a computer These foreign devices must have the computer like intelligence to communicate in the prescribed protocol Although some of these devices may not be thought of as computers for simplicity in this manual we refer to them all as computers Chapter 1 Using This Manual Manual Organization Chapter Summary This manual is organized into the following chapters Chapter What s Covered Eo aem E This Manual
62. empts that result in local faults can take many times as much time as the normal message transfer time This could adversely affect the performance of other nodes You can reduce the impact of automatic retries by providing a time delay before each retry as shown in Figure 5 20 In this example a 5 second time delay was added to the example in Figure 5 18 When the local or remote fault bit goes ON the timer starts Only after the 5 second time delay is the start bit turned on again to initiate an automatic retry of the command 5 31 Chapter 5 Programming the Local Host Figure 5 20 Retry Delay Rung 1 Input Compare Transition 111 011 020 jp L 11 11 00 Input Compare 111 011 J E 11 11 Rung 2 Input Compare 111 011 m 11 11 Rung 3 Transi tion Timeout Done Start 020 035 032 032 1 H dr x 00 15 02 12 Rung 4 Local Remote Fault Fault 033 033 035 TOF 02 12 0 1 PR 050 Rung 5 AC 000 Done Transition 032 020 d U 02 00 Monitoring Remote Local Fault Bit When it cannot execute a command the PLC 2 DHII interface sets a remote or local fault bit ON These bits in the data table of the local host processor are located in the word immediately following the start done word They indicate not only that a command was not executed but also point to the general type of fault condition which prevented command completion 5 32 Chapter 5 Programming the Local Host
63. evel 115V 230V of the AC power source 3 Push the removable frame back to the operating position 4 Tighten the four thumbscrews on the front of the interface The thumbscrews must be tight to ensure that AC power is not interrupted by the interlock switch on the power supply board 5 Lock open the main disconnect switch to remove all power to the enclosure WARNING Do not attempt to connect power conductors to the power terminals without first locking open the main disconnect switch Failure to heed this warning could cause you to receive a dangerous electrical shock 6 Connect the GND post on the removable frame to the central ground bus The central ground bus must connect to the grounding electrode 4 15 Chapter 4 Installing the PLC 2 DHII Interface 4 16 system through a grounding electrode conductor The interface is shipped to you with a wire connecting the post to the stationary frame and another wire connecting the post to the GND terminal of the terminal block When you ground the post on the removable frame you thereby also ground the stationary frame and the power supply board Figure 4 13 7 Connect the L2 N terminal to the low side of the transformer supplying the AC power Figure 4 13 8 Connect the L1 terminal to the high side of the transformer supplying the AC power Figure 4 13 9 Install the supplied terminal cover over the terminal block WARNING Do not leave these terminals exposed
64. g Link Address Setting Host Board Switches Chapter 4 Installing the PLC 2 DHII Interface On the front of the PLC 2 DHII interface is a set of three link address thumbwheel switches Figure 4 3 Set these switches to designate the link address of the node The top switch represents the most significant digit MSD The bottom two switches do not go past the digit 7 this is because the link address must be an octal number The top switch does not go past the digit 3 this is because the highest link address settable is 377 The values 000 and 377 are invalid link addresses Also the 1770 T3 Industrial Terminal cannot address Words 000 through 007 or 100 through 107 in the processor work areas in the PLC 2 programmable controllers Select a number from 010 through 077 or 110 through 376 Give each node of the link a unique link address The token will pass from node to node by order of link address Figure 4 3 Link Address aN igs TEST wG RESET ne MSD sat activity NORMAL 5 wy O M LINK ADDRESS PROGRAM ACTIVE INTERACE COMM ERRO S O COMPLETE PROCESSOR BROS ERR Lo At each of the four latches on the front of the interface is a captive screw You can tighten or loosen these screws by hand with the knobs of the screws Loosen the screws then grasp the knobs to pull the removable frame out 3 inches to the switch setting position
65. g done bit for each of up to eight commands If you program more than eight command rungs at a station you must provide for additional preferably contiguous pairs of start done and remote local fault words Chapter 5 Programming the Local Host Select the start bit for any command in the upper byte Bits 10 17 of the start done word The done bit for this command is then the corresponding bit in the lower byte Bits 00 07 of the same word In Figure 5 11 A the sample command rung examines Bit 03210 as its start bit As Figure 5 11 B shows the corresponding done bit is Bit 03200 Note that the address of start done bits for each command differs only in the next to last digit the start bit always has a 1 in the next to last digit the done bit always has a Figure 5 11 Adjacent Status Words A Command Rung Start Bit 03210 02707 H emee Selection of Start Bit Automatically Desig B Start Done and Remote Local Fault Words nates Bits in Two Adjacent Words Start Bits Done Bits 7A P4 m gt Word 032 2 2 Program PLC 2 DHII Controlled Interface Controlled mE E Y v 7 Y v gt Word 033 4 Remote Fault Bits Local Fault Bits Bits for Command Rung Shown As it name implies the start bit initiates command execution This bit controlled by the user program is set ON to initiat
66. hat it no longer wants to be included in the logical ring After accomplishing this exit the interface turns on the EXIT COMPLETE indicator From then on until the interface is reset the other nodes will not attempt to pass on the token to this node Press the EXIT REQUEST switch before turning off interface power or switching out of the RUN position If you don t press this switch before turning off interface power or switching out of the RUN mode the other nodes in the ring will waste time trying to pass the token to this node for a while before giving up TEST RUN RESET Switch The TEST RUN RESET switch is a three position toggle switch that controls the operation mode of the interface TEST and RUN are stationary contact positions RESET is a momentary contact position To change switch position you must first pull out on the switch handle This feature guards against switching out of the RUN position inadvertently To switch to the TEST position first switch to RESET momentarily In the TEST position the interface continuously executes self diagnostic tests Each test cycle lasts approximately 50 seconds During these tests the NODE TEST and MAC TEST indicators turn on and the IN RING SEEKING MEM and DUP ADDR indicators flash rapidly Chapter 6 Operation and Troubleshooting In the RUN position the interface can communicate with other nodes of the Data Highway II link When you power up the interface in the RUN position it
67. he local node data table bounded by the second and third GET elements in the rung Only one set of GET elements as shown in Figure 5 6 is allowed in a single command rung 5 9 Chapter 5 Programming the Local Host Figure 5 6 General Block Command Format Remote Station Start Bit Local Station P Data Table Boundaries a ae te BBB CCC DDD 027 18 1 19 18 07 t e Command Code Remote Station Starting Data Table Address Legend BBB Beginning Word Address at REMOTE Station for WRITE READ Operation CCC Beginning Word Address at LOCAL Station for WRITE READ Operation DDD Ending Word Address at LOCAL Station for WRITE READ Operation Bit Command Format Use the format shown in Figure 5 7 when you enter a command code specifying any of the following commands Protected Write Bit with No Reply Protected Write Bit with Reply Unprotected Write Bit with Reply Protected Write Bit Verified This format uses examine elements which address bits in the remote node These elements control remote node data table bits as follows EXAMINE ON This rung element instructs the remote node to turn on the addressed bit EXAMINE OFF This rung element instructs the remote node to turn off the addressed bit These elements are programmed immediately following the command code Any combination of these elements may make up this type of command rung
68. ied Write Block mmediate Access Commands Read Immediate Access Block Update Immediate Access Block Accepted Commands The PLC 2 DHII interface can accept commands from remote nodes The interface will interpret the command check switches and programming rungs for restrictions and execute the command without any extra programming on the user s part The following is a list of command types accepted Generated Commands Other Data Transfer Commands Upload Download Diagnostics Remote Programming Remote Command Control Commands Third Party Station Management Generated Commands Obviously the PLC 2 DHII interface can accept all commands that it can generate All read write bit write block and immediate access commands are accepted by the interface Chapter 2 Introducing the PLC 2 DHII Interface 2 16 Other Data Transfer There are more data transfer commands available on Data Highway II that can be generated with the KP2 They increase in complexity with the processor used They still move data from one place to another but they have different formats The KP2 can interpret some of these and execute them successfully Upload Download A computer can download or upload user programs into the memory of a PLC 2 via the node interface using upload download commands Diagnostics Likewise a computer can check the current state of the interface as well as that of the PLC via the diagnosti
69. ink Cabling Hardware 3 1 Chapter 34 Identifying Hardware 3 1 Planning Cabling Configuration 3 4 Taps and Length of Trunkline 3 4 Installing Taps 3 10 Installing the Trunkline 3 11 Plugging into the Tap 3 14 Installing 5 3 15 Chapter Summary Table of Contents Installing the PLC 2 DHII Interface Chapter Planning the Layout Mounting the PLC 2 DHII Interface Setting Link Address Setting Host Board Switches Setting MAC Board Switches Connecting Communication Cables Connecting Power and Ground Power Distribution Chapter Summary Programming the Local Host Chapter Communication Zone Salus WONG e imei cce adeo GP ER RES Initiati
70. ionary frame 6 Push the removable frame back to the operating position 7 Reconnect the green conductor for grounding the stationary frame to the ground post on the removable frame Figure 4 5 4 8 Chapter 4 Installing the PLC 2 DHII Interface Figure 4 6 MAC Board Switches Shield Down Up Power Supply Board Connecting Communication After you have set the host board switches to select the type of operation Cables you want you can begin connecting the communication cables necessary for your application Cables that you might connect to the PLC 2 DHII interface are listed in Table 4 A Table 4 A Cables Catalog Number Name Length Connects 1771 CN 1 5 feet 0 46 m PROCESSOR connector to a mini processor module PROGRAM INTERFACE connector to a second interface or communication module 1771 CO 3 4 feet 1 m PROCESSOR connector to a mini processor module PROGRAM INTERFACE connector to a second interface or communication module 1771 CR 10 feet 3 1m PROCESSOR connector to a PLC 2 20 or PLC 2 30 processor PROGRAM INTERFACE connector to a second interface or communication module 1772 TC 10 feet 3 1 m PROGRAM INTERFACE connector to a programming terminal Local Tap Dropline 2 feet 0 62 m DATA HWY II PORT jack to a tap Do not connect any cable to the DHII AUX ACCESS connector This is reserved for future product enhancement Chapter 4 Installi
71. ke into consideration the surge currents of devices controlled by the controller The minimum transformer rating requirement for the PLC 2 DHII interface is 125V AC DHII power supplies that are set up for 115V AC operation are designed to generate a shutdown whenever the AC line voltage drops below 85 volts and to allow the interface to resume operation when the line voltage reaches 85 volts again For power supplies that are set up for 230V AC operation the shutdown level is 170V AC Chapter 4 Installing the PLC 2 DHII Interface Chapter Summary 4 18 If the transformer is too small it will clip the peak of the sine wave before the voltage drops below 85 volts The power supply will sense this as a low voltage and shut down the interface prematurely Allen Bradley power supplies have circuits which suppress electromagnetic interference from other equipment For installations near particularly bad electrical noise generators an isolation transformer can provide further suppression of electromagnetic interference from other equipment In applications where the AC power source is especially soft and subject to unusual variations a constant voltage transformer can stabilize the AC power source to the interface thereby minimizing shutdowns Now that you have installed the PLC 2 DHII interface connecting it between a PLC 2 family processor and a Data Highway II link dropline you are ready to read about how to program the
72. kline length can be up to 4 100 cable feet Refer to Chapter 3 for detailed information on planning cable lengths The Data Highway II link provides carrier band signaling through frequency shift keying The carrier frequency is 5 MHz The carrier is modulated to 6 25 MHz for a data high signal and 3 75 MHz for a data low signal Because it has a carrier band medium the Data Highway IIlink provides high noise immunity at a high data transmission rate 1 Mbit s over its long permissible cable lengths Because the Data Highway II link has a carrier band bus medium only one node can transmit at a time However each node in a Data Highway II link has a regularly scheduled opportunity to access the medium to transmit messages to other nodes This peer to peer communication between nodes is provided by the Data Highway II link through token passing The token passing is self initiating The nodes form a logical ring The token is passed around the ring to each node on a regular schedule thereby making throughput and response time predictable While a node possesses the token it is the master Only the master can initiate communication After a node has had the opportunity to transmit messages for the prescribed period of time it passes the token on to the next node 2 9 Chapter 2 Introducing the PLC 2 DHII Interface Bridges to Other Data Highway Links Command Reply 2 10 At this time the Data Highway II network does not
73. mand Rung 1 Input Compare Transition 111 011 020 1 Af lL 11 11 00 Input Compare 111 011 JI T 11 11 Rung 2 Input Compare 111 011 pa u 11 Rung 3 Transi Remote Local tion Fault Fault Done Start 020 033 033 032 032 hp a i eb J 00 12 02 02 12 Rung 4 Done Start 032 032 I U 7 4 02 12 Timed You can turn on the start bit periodically to send a command at a user determined interval Figure 5 19 shows example rungs for this type of command initiation In this example Timed Bit 04615 is used to initiate the command at every preset interval 10 seconds This bit is examined to turn on the start bit In normal operation after the command is executed the done bit is set ON by the module This causes the program to reset the timer and turn off the start bit The timer then begins timing again once the done bit is OFF As Figure 5 14 shows the done bit is reset only after the start bit is turned off Note that this programming causes continuous retry of a command in the event of faulted operation 5 30 Chapter 5 Programming the Local Host Figure 5 19 Timer Initiated Command Done 032 046 1 TON 02 1 0 PR 010 000 Timed Remote Local Bit Fault Fault Start 046 033 033 032 ju MEE 15 12 02 12 Retry Delay In some cases automatic retry as implemented in Figure 5 16 Figure 5 18 and Figure 5 19 can load down the network unnecessarily Message transfer att
74. mmand is larger than area assigned or data in read command is smaller than amount requested B4 Data table in host device at remote node cannot be written to or read from B5 Area of memory in host device at remote node cannot be written to or read from B6 Memory address not specified or invalid B7 Field is missing from message packet B8 Timer timed out before message was executed B9 Host device at remote node is in the wrong mode to receive commands BA Size parameter in time critical command too large and exceeds maximum read BB Read modify write words command exceeds number of words you can read modify write BC Read immediate mismtach Cannot guarantee delivery of message Link layer time out or received Duplicate token holder detected by link layer Local port is disconnected Attempt to send invalid command Bad source link address in response Message timeout execution time exceeds timeout preset value 81 Illegal command 82 Station processor communication problem 83 Remote station processor faulted or OFF 84 I O fault at remote station processor 85 Command transmitted not allowed by switch setting or memory access rung programming at remote station 86 Command transmitted not allowed by switch setting at remote station 87 Remote station processor in program or program load mode 88 Communication zone invalid at remote station processor 89 Remote station communication adapter module unabl
75. mming manual for that processor or the manual for its node interface Further general memory access limitations are discussed in the following sections Memory Access Rungs A remote node may have memory access rungs giving memory access of parts of its data table to certain nodes If your address is not specified in the remote communication zone your protected write commands will be rejected Writes Switch Disabled A node interface will not accept writes to its data table unless it has a switch set to the proper position to accept writes to its data table Write Bit Access You can use a write bit command to control any accessible data table bit However do not use this to control Any bit whose status is controlled by an output instruction in the ladder diagram program Any bit in a byte which also contains program bits in the PLC 2 family processor The first restriction simply states that you must not attempt to directly control a bit by both an output instruction in the local ladder diagram program and a write bit command from a remote node This rule applies to all PLC processors Chapter 5 Programming the Local Host Write bit commands are generally used to set storage bits in the data table of a remote node These storage bits can then be examined in the program as conditions to energize an output bit This indirect programming technique not only allows control using write bit commands but also helps to preven
76. mmunication with some other node As with automatic timeout preset monitoring a user programmed timeout is useful as a backup to the other monitoring functions of the PLC 2 DHII interface Remote and local fault bits at other nodes indicate the same types of faults that can be detected using a user programmed timeout A programmed timeout would not be necessary for each command from a node Instead you can monitor a single command at each node in this manner For this type of monitoring select a command that is sent regularly 5 39 Chapter 5 Programming the Local Host Memory Access Limitations 5 40 There may be other instances where program monitoring of commands is useful In some cases you might program a timeout to monitor the execution time of critical commands An application may require that a time critical message such as a command to read an immediate access block be sent within a certain limited amount of time You can program a TON instruction for this purpose here however its preset interval will generally be shorter than the interval entered as the timeout preset for the module You can also use the second timeout allowed in the header rung with a smaller timeout preset to more closely control your time critical commands Before transmitting write commands to a remote node you should become aware of what areas of that node s data table is accessible to you This information is available either in the progra
77. n and its control of the fault and done bits is asynchronous to the PLC processor s scan and its control of the start bits 5 23 Chapter 5 Programming the Local Host Normal Operation Command execution begins when the ladder diagram program turns on a start bit normally with a latch instruction The PLC 2 DHII interface detects the ON state of this bit and then begins the operation necessary to format and transmit a command message When the remote node interface receives the command message it acknowledges it Then while normal operation continues the remote node interface reacts to the command and prepares a reply message except for a write with no reply The remote node interface waits until it receives the token then transmits its reply message to the local calling station When the local PLC 2 DHII interface receives the reply it turns on the done bit at the host processor The done bit in turn is examined in the ladder diagram program to turn off the start bit After the start bit has been turned off the PLC 2 DHII interface resets the done bit Timing of start and done bits for a command is shown in Figure 5 14 The significance of start done bit status is summarized in Table 5 A Figure 5 14 Start Done Bit Timing Normal Operation Command Host Proc PLC 2 DHII i LA essor Scan Interface Scan ime Done Bit ON y LEGEND A Start Bit turned ON by the program Done Bit set ON
78. n as a fault bit goes ON this bit goes ON thereby turning on the indicator Once ON the indicator remains on as long as the timer is timing that is for at least as long as the preset interval In the example of Figure 5 22 this preset is two seconds We recommend this value be set at no less than 0 5 seconds Figure 5 22 Fault Bit Diagnostic Rungs Multiple Commands Example Rung 1 Fault Constant Status 040 033 030 9 lt TOF 000 000 0 1 PR 020 Output Timed Bit Indicator 030 010 11 A 15 00 Chapter 5 Programming the Local Host The OFF delay timer is useful in this application because it is continually reset when its rung conditions go true This means that the timed bit Bit 03015 remains on for a long as any fault bit is changing state during programmed retries This keeps the output indicator on until after the done bit indicates command completion Of course other methods can be used to monitor remote and local fault bits Such factors as availability of output terminals memory space and type of application dictate the specifics of fault bit monitoring and program response Synchronizing Fault Bits As noted earlier the PLC 2 DHII interface s scan and its control of the fault and done bits is asynchronous to the PLC processor s scan and its control of the start bits In the examples discussed so far as in most applications this lack of synchronization does not present any problems Howe
79. n the EXAMINE ON element specifies the remote node The word address in the first GET element specifies the starting address of the memory access block The word address in the second GET element specifies the ending address of the memory access block These elements must be followed by a branch end Figure 5 3 B shows the block of words in memory that is now open to writes from Remote Node 010 due to the memory access branch of Figure 5 3 A Memory access branches can be listed in a single memory access rung Note that each group of elements must be preceded by a branch start This is true in all cases even where only one memory access branch is defined Branch end must be used to fit the memory access rung into the ladder diagram display format You must end each memory access rung with an Energize Output 02707 element 5 5 Chapter 5 Programming the Local Host 5 6 Figure 5 3 Memory Access Example A Memory Access Branch B Local Host Data Table Showing Block Accessible to Protected Memory Access Block Writes from Remote Node 010 Boundaries in Local Host Data Table Block Accessible GF SS to Write Commands 4 from Remote Remote Starting Ending Node 010 Node Address Address 7 Words 020 010 020 023 HaHa 00 000 000 023 Vj Wy 4 Branch Start Branch End 22 42 2 Instruction Instruction Required Required 2 Figure 5 4 shows a memory access rung with
80. n the printed circuit board just above each switch assembly Use a blunt pointed instrument such as a ball point pen to set these switches Never use a pencil lead could jam the switch 4 6 Chapter 4 Installing the PLC 2 DHII Interface Accept Writes to Program Area The accept writes to program area switch selections are OFF The interface rejects commands to write into the program area of the host ON The interface accepts commands to write into the program area of the host Accept Writes to Data Table The accept writes to data table switch selections are OFF The interface rejects commands to write into the data table of the host ON The interface accepts commands to write into the data table of the host Accept Network Parameter Changes The accept network parameter changes switch selections are OFF The interface rejects commands to change network parameters stored on the interface for this node ON The interface accepts commands to change network parameters stored on the interface for this node Accept Third Party Requests The accept third party requests switch selections are OFF The interface rejects any command from another node for this node to transmit a command to a third node ON The interface accepts commands from another node for this node to transmit commands to a third node First Second Interface The first second interface switch selections a
81. ndicate that this node is seeking membership f another node interface is connected in the Data Highway link in the RUN position the SIG QUAL indicator turns green and then the IN RING SEEKING MEM indicator turns from yellow to green to indicate that this node is now logically in a ring and receiving a token periodically is a cabling problem or no other node interface is in the RUN position every ten seconds the MAC board goes through a one second self diagnostic test This is indicated by the MAC TEST indicator turning yellow and the IN RING SEEKING MEM and REDUN WARN indicators flashing rapidly f another node on the link has the same address the DUP ADDR indicator on either this node the other node or both will turn red Exactly which will occur cannot be determined because of the random position of the token 6 5 Chapter 6 Operation and Troubleshooting Replacing Boards 6 6 Whenever you want to turn off interface power or switch out of the RUN position press the EXIT REQUEST switch first This exit request saves the other nodes time they would otherwise waste trying to pass the token to a node that they can t find If you determine through the troubleshooting procedure that one of the interface boards has faulted replace it with a spare Electrostatic discharge can damage integrated circuits or other semiconductors in these boards if you touch connectors or pins Avoid electrostatic damage by
82. ng and Monitoring Commands Memory Access Chapter Summary Operation and Troubleshooting Chapter le sees odse aniei Operation Switches Operating the KP2 Interface Replacing Boards Troubleshooting the Interface Error Chapter Summary Specifications EITOP COdOS Chapter zio A n2 99 AB AB PO e 1 iO i amp gt 1 D o A A T w UJ UJ Using This Manual Chapter Objectives This chapter tells you about this manual It explains this manual s purpose audience and content Manual s Purpose In this manual you will read about the PLC 2 DHII Interface Cat No 1779 KP2 and the Redundant PLC 2 DHII Interface Cat No 1779 KP2R You will see how to install and use a PLC 2 DHII interface in a Data Highway II communication network Audience Plant
83. ng the PLC 2 DHII Interface 4 10 To PLC Processor You must connect a cable from the PROCESSOR connector on the interface to the PLC processor Figure 4 7 Use a 1771 CN or 1771 CO cable for connection to a Mini PLC 2 Mini PLC 2 05 or Mini PLC 2 15 processor Use a 1771 CR cable for connection to a PLC 2 20 or PLC 2 30 processor Figure 4 7 Connection to the PLC 2 Family Processor ooo OO OO OOOO x Industrial Kk Terminal 2 PLC Processor INTERFACE or PROGRAM PANEL Connector Interconnect Cable cat no 1771 CN 1 5 ft cat no 1771 CO 3 5 ft cat no 1771 CR 10 ft Chapter 4 Installing the PLC 2 DHII Interface To Programming Terminal To use an Industrial Terminal with the PLC processor connect a 1772 TC cable from the PROGRAM INTERFACE connector on the interface to the connector on the Industrial Terminal Figure 4 8 With this connection you cannot use tape cassette functions through the Industrial Terminal If you use two interfaces with the same processor Figure 4 10 you must use a 1770 T3 Industrial Terminal with Revision F or later firmware Figure 4 8 Connection to a Programming Terminal OO 0000
84. nimum Bend Radius 3 inch 3 6 Use No 5 mounting bolts 2 Places Chapter 3 Installing Data Highway II Link Cabling Hardware Tap Mounting Layout Figure 3 9 shows the mounting dimensions of a tap However you can mount a tap in any position or orientation Mount each tap in a position convenient for your trunkline cable routing which will not violate the 6 inch minimum bend radius Figure 3 9 Tap Mounting Dimensions 2 1 in 54 mm 1 5 in 1 0 38 zi 25 mm CI Y lis 3 1 in 79 mm 0 2 in 6 mm Clearance Depth m AE 5 in 77 mm 12644 To allow sufficient air flow for cooling of the node interface mount the tap a minimum of 2 inches from the node interface To allow the dropline cable enough slack to not violate the 3 inch minimum bend radius mount the tap a maximum of 11 inches from the 3 7 Chapter 3 Installing Data Highway II Link Cabling Hardware 3 8 bottom or left side of the node interface Avoid routing the dropline cable over AC power terminals on the node interface The PLC 3 interface module 1779 KP3 requires further restrictions because it is inside of the PLC 3 processor chassis Mount the tap a maximum of 5 inches from the chassis Furthermore you can only mount the tap on the side of the chassis if the PLC 3 interface module is
85. node into the disconnect state and turns on the MAC FAULT indicator REDUN WARN A valid signal is being received at only one of the two Data Highway II ports ae d This indicator is only on the redundant interface The extended tap has failed or its dropline connection to the port has opened This indicator can only go on if the switch on the MAC board is set for extended tap EXTENDED TAP CONFIG On Yellow The switch on the MAC board is set for the interface to connect to an extended tap AC POWER ON On Yellow The interface is receiving AC power through the fuse and the AC power switch DC POWER ON The power supply board is generating DC power at an acceptable level 6 3 Chapter 6 Operation and Troubleshooting Operation Switches 6 4 The interface has three switches on its front panel for you to use in operating the interface Figure 6 1 AC POWER Switch EXIT REQUEST Switch TEST RUN RESET Switch AC Power Switch The AC POWER switch is a toggle switch In the on position this switch connects power from the input power terminals through the fuse to the power supply circuits With the proper voltage level of AC power connected to the power supply circuits through the AC POWER switch the interface turns on the AC POWER ON indicator Exit Request Switch The EXIT REQUEST switch is a push button switch When you press this switch the interface sends out a signal to the other nodes of the Data Highway II link t
86. o the other nodes of the Data Highway II link the host device and its interface combined are accessed as a single node of the Data Highway II link Chapter 2 Introducing the PLC 2 DHII Interface Programming The program in a host device at one node can initiate a transfer of a message to or from any other node in the network We describe programming a host device for communication through a 1779 KFL interface in later chapters Figure 2 5 A Data Highway Il Network with Two Data Highway Il Links 8200 CNC 8200 KDHW Dumb Interface Terminal RS 422 449 Link RS 232 C Link 50 Cable Feet Max 4 000 Cable Feet Max d RS 422 Link 4 000 Cable Feet Max 1779 KFM Interface 1779 KFL Interface Data Highway II Link PA Data Highway II Link ZL Bridge 1779 KP3 1779 KP2 1779 KP2 Interface Interface Interface PLC 3 PLC 2 15 PLC 2 30 Processor Processor Processor 13291 2 7 Chapter 2 Introducing the PLC 2 DHII Interface 2 8 Host Interface Links In many applications it is essential for nodes in a Data Highway II link to communicate with devices such as Computers Color Graphic Terminals Dumb Terminals Robots Computerized Numerical Controls CNC These devices must communicate through a local host interface link and a node in
87. on the back panel of an enclosure Figure 2 1 The removable frame fastens to the stationary frame The removable frame contains the power supply board the PLC 2 host board and the media access controller MAC board A shield separates the power supply board from the PLC 2 host board and the MAC Figure 2 2 2 1 Stationary Frame Removable Frame 06060000 000000 PLC 2 DHII Interface with Removable Frame Separated from Stationary Frame Figure 2 1 E en cy a cC o E 5 o E Chapter 2 2 2 What Is Its Function Chapter 2 Introducing the PLC 2 DHII Interface Figure 2 2 Rear View of the Removable Frame Assembly Shield 3M NO 3394 vy6 ON WE Power Supply MAC Host Board Board Board 12617 The PLC 2 DHII interface functions as a communication interface between a PLC 2 family processor host processor and other nodes of a Data Highway II link Figure 2 3 The power supply board converts AC power to DC power that the PLC 2 host board and MAC board use The power supply board accepts either 120V AC OR 220V AC 60 Hz The PLC 2 host board communicates with the PLC 2 family processor The MAC board communicates with the other nodes of the Data Highway II link through the coaxial cable medium 2 3 Chapter 2 Introducing the PLC 2 DHII Interface Compatible Process
88. onnection to a Second PLC 2 DHII Interface First Interface Second Interface x i 8 5 Interconnect Cable e Ce cat no 1771 CN 1 5 ft cat no 1771 CO 3 5 ft 85 cat no 1771 CR 10 ft J 1771 T3 Series B Rev F o o Industrial Terminal O O Ve Qr o G S S S Bon Bon To 1771 KG Module Another possibility of providing a second link is to connect a 1771 KG module for an RS 232 C link in place of either the first or second interface in Figure 4 10 Connect a 1771 CN CO or CR cable from the PROGRAM INTERFACE connector on the first to the PROCESSOR connector on the second 4 13 Chapter 4 Installing the PLC 2 DHII Interface To 1771 KA2 Module Another possibility of providing a second link is to connect a 1771 KA2 module for a Data Highway link in place of either the first or second interface in Figure 4 10 Connect a 1771 CN CO or CR cable from the PROGRAM INTERFACE connector on the first to the PROCESSOR connector on the second To Tap Pull the removable frame out to the switch setting position before connecting to the tap This is the only way to
89. ors Communication Connections 2 4 The PLC 2 DHII interface is compatible with these PLC 2 family processors Mini PLC 2 Processor Cat No 1772 LN1 LN2 LN3 Mini PLC 2 05 Processor Cat No 1772 LS LSP Mini PLC 2 15 Processor Cat No 1772 LV PLC 2 20 Processor Cat No 1772 LP1 LP2 PLC 2 30 Processor Cat No 1772 LP3 Figure 2 3 A PLC 2 Family Processor Communicating with Other Nodes through a PLC 2 DHII Interface PLC 2 DHII Interface Power Supply Board Host Processor Meda pe Dither Nodes PLC 2 Family Host Access of the Processor Board Board Data Highway II Communication IIT le aod The PLC 2 DHII interface communicates through connectors on its front surface Figure 2 4 The PROCESSOR connector provides cable connection to the PLC 2 family processor At the PLC 2 family processor the cable mates with the connector provided for Industrial Terminal use The PROGRAM INTERFACE connector provides cable connection to an Industrial Terminal for the PLC 2 family processor When connected to the PROGRAM INTERFACE connector the Industrial Terminal behaves as though it were connected directly to the PLC 2 family processor port The DATA HWY II jack provides dropline cable connection to a tap on a Data Highway link A redundant PLC 2 DHII interface has a second DATA HWY II jack for a redundant set of cabling for the link Th
90. ottom ribbon cable Figure 6 5 Failure to heed this caution could cause damage to the boards 20 Slide the removable frame back onto the stationary frame 21 Tighten the four thumbscrews on the front of the interface The thumbscrews must be tight to ensure that AC power is not interrupted by the interlock switch on the power supply board 22 Reconnect the cables to the front of the interface 23 Reconnect the green conductor for grounding the stationary frame to the ground post on the removable frame Figure 6 2 24 With AC power disconnected at the source disconnect switch or circuit breaker Reconnect the AC power connection to L1 and L2 N and the ground connection to the GND post on the interface 25 Reconnect the AC power at the source Figure 6 5 Misalignment of Pins on Bottom Ribbon Cable Connector Chapter 6 Operation and Troubleshooting Troubleshooting the Interface When you suspect that the interface is not functioning properly follow these steps Figure 6 6 1 Check the AC POWER ON indicator OFF If off check the AC POWER switch setting fuse AC source voltage and interlock switch If you still haven t found the source of the problem try replacing the power supply board ON If on proceed to Step 2 2 Check the DC POWER ON indicator 6 11 Chapter 6 Operation and Troubleshooting 6 12 OFF If off turn the AC POWER
91. ow Cabling System A and Cabling System B for Data Highway II Each cabling system provides backup for the other Each node interface attempts to transmit each outgoing message across both cabling systems Each node interface continuously monitors the quality of the signal it receives from each cabling system As a node interface receives a message it always accepts the message from the cabling system providing the better signal quality If a cable in Cabling System A becomes damaged each node interface accepts its incoming messages from Cabling System B If Cabling System B becomes damaged each node interface accepts its incoming messages from Cabling System A Figure 2 9 Redundant Cabling Configuration for a Data Highway II Link Trunkline Cabling System A Trunkline s dh Tap Tap Tap Dropline Dropline SS Redundant Redundant Redundant Node Node Node Interface Interface Interface Dropline 3 Dropline 3 Tap Tap Tap M 4 A Trunkline Cabling System B Trunkline Chapter 2 Introducing the PLC 2 DHII Interface A Second Link You can provide two separate communication links for a PLC 2 family processor For example you can connect a 1771 KA2 module and a 1779 KP2 interface to provide both a Data Highway link and a Data Highway II link respectively through
92. pe The following sections explain the communication zone rungs in detail Actual communication zone rungs for any host processor may vary If for instance a PLC 2 will not generate any messages and will accept all messages from other nodes you need not enter a communication zone at all The length of this zone is a function of the number of remote nodes with which the local host processor communicates and the number of types of commands to be sent to these remote nodes 5 1 Chapter 5 Programming the Local Host Header Rung El Memory Access Rung Immediate Access Update Rung Read Immediate Read Write Block Write Bit Delimiter Rung H 5 2 Figure 5 1 Format of a Communication Zone START 022 077 030 012 027 a GG L 00 07 020 070 076 017 022 022 027 1 Hema el 0 00 00 07 017 063 065 010 060 062 00 00 024 200 217 022 027 1 meme It 10 00 07 032 022 040 047 027 eame 2 17 07 032 020 016 022 024 027 aea Co 100 XX 07 032 017 120 120 120 120 027 ht Ge ede urbs ut Co o 0 0 0 07 120 120 120 120 pq RA EP 04 05 6 0 120 120 135 126 0 n t 00 027 07 Program the header and delimiter rungs for each host processor Program the other rungs as needed Chapter 5 Programming the Local Host Here are the communication zone rungs that go in your ladder diagram program
93. r PLC processor for example and its interface to the Data Highway II link make up a station A station is an input output point in the communication system A node is the point at which each station accesses the medium Because each station communicates through a node on the Data Highway II link it may appear that we use the terms node and station interchangeably at times However we will show later that there is not always a one to one relationship between stations and nodes Within a station that contains a synchronous device or asynchronous device interface a local host interface link is required for access to the Data Highway II link Two nodes for such stations are shown in Figure 2 5 One node comprises a 1779 KFM interface to a computer through an RS 422 449 link limited to 4 000 cable feet Another node comprises a 1779 KFL interface to two host devices Each 1779 KFL interface has two channels for connection to two standard link devices at the same time Through either channel it can interface either an RS 232 C compatible device or an RS 422 compatible device to the Data Highway II link Although the host interface links are not Data Highway II links they are a part of the Data Highway II network In each case the device is the host for the interface A host device is a node on one end of its host interface link and its interface to the Data Highway II link is a node on the other end of the host interface link However t
94. ration and Troubleshooting Figure 6 1 KP2 Front Panel NODE PASS HOST FAULT O MAC FAULT NODE TEST O MAC TEST TEST RUN RESET MSD sar O ACTIVITY L LINK dO ADDRESS PROGRAM ACTIVE INTERFACE COMM ERR O EXIT O COMPLETE PROCESSOR PROG ERR PROC ERR EXIT REQUEST Or 9 INRING Y SEEKING MEM O puP ADDR O REDUN WARN PORT READY O SIG QUAL O TAP FAIL DATA O PORT READY HWY II SORT O SIG QUAL 2 O TAP FAIL DC POWER ON e 88 o9 AC POWER ON 0 9 DH II 9 26 AUX 80 ACCESS 9g o9 96 o9 ON PROGRAM AC POWER INTERFACE 52 99 o SLOW BLOW EXTENDED FUSE o L 2A 250V 115V AC 230V AC m INTERNALLY DATA SWITCH HWY II SELECTABLE PROCESSOR 1 PORT Qiu QD van DATA o E 2 PORT CAT NO 1779 2 DHII PLC 2 INTERFACE J 6 2 Chapter 6 Operation and Troubleshooting NODE PASS The host and MAC boards performed and passed self diagnostic tests HOST FAULT The host board has either 1 failed the self diagnostic test or 2 faulted while in operation NODE TEST The host and MAC boards are performing self diagnostic tests AC
95. re OFF First Interface Use this selection if you connect this interface directly to the PLC 2 family processor ON Second Interface Use this selection if you connect this interface to the PROGRAM INTERFACE connector on another PLC 2 DHII interface or on a 1771 KG 1771 KA2 or 1770 KG module discussed in the following paragraphs 4 7 Chapter 4 Installing the PLC 2 DHII Interface Setting MAC Board Switches The MAC board has two switches Set Switch 1 to the UP position Switch 2 is not used and can be in either position To set the switch follow these steps 1 With the removable frame in the switch setting position disconnect the green equipment grounding conductor from between the stationary frame and the ground post on the removable frame Figure 4 5 Figure 4 5 Green Conductor Connecting the Stationary Frame to the Ground Post on the Removable Frame 115V AC 230V AC INTERNALLY SWITCH SELECTABLE L1 L2 N Green Grounding Conductor slolessie 2 While holding the removable frame at the top and bottom lift in up an inch and then out away from the stationary frame 3 Locate the switches at the rear edge of the MAC board middle board between the bottom two ribbon cables Figure 4 6 4 Setthe switch with your finger 5 Slide the removable frame back onto the stat
96. rized part may greatly reduce the reliability of the link 3 1 Chapter 3 Installing Data Highway II Link Cabling Hardware 3 2 Coaxial Cable Use RG 11 type coaxial cable for the trunkline The RG 11 type coaxial cable has both a foil and a braided wire outer conductor Figure 3 1 Figure 3 1 Coaxial Cable Braid Foil pm Inner Conductor Insulation Insulating Jacket Local Tap Each node of a Data Highway II link requires a local tap Each local tap has two trunkline jacks a dropline jack and a cap for covering the dropline jack when you do not have a dropline connected With each local tap we also ship Figure 3 2 two cable plugs for connecting the trunkline cables to the trunkline jack on the tap and dropline cable assembly 2 feet maximum for connecting a node interface to the dropline jack on the tap Figure 3 2 Local Tap Sleeve Pin o o Chapter 3 Installing Data Highway II Link Cabling Hardware Straight Plug Body p Trunkline Jack Dropline Jack Right Angle Plug Ys 44 Crimping Tool oe 4 Cable Plugs 2 Tap Dropline Cable Assembly You will need the crimping tool for fastening the cable plugs to the trunkline cable segments Figure 3 3 Figure 3 3 Crimping Tool
97. t recent error code written by the PLC 2 DHII interface Figure 5 13 shows the structure of the error word The lower byte of this word Bits 00 07 stores any error code entered by the PLC 2 DHII interface In this byte the error code is represented as a two digit hexadecimal number Figure 5 13 Error Code Word Format Two Digit Value 8 Reference Number for Codes D2 E7 Hex a Counter for Codes 10 CF Hex Error Codes 00 FF Hex Format Hex Count Refer to Appendix B 17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00 5 21 Chapter 5 Programming the Local Host 5 22 Appendix B lists status codes Error codes can be grouped as follows Codes D2 through E7 indicate that the PLC 2 DHII interface has detected some programming error in the communication zone of the program The program status indicator PROG ERR will be ON if one of these codes is displayed Codes 10 through CF generally indicate the PLC 2 DHII interface has detected some programming or hardware related fault during attempts at communication between nodes These codes are intended to serve as diagnostic indicators after the initial power up checks of program have been completed The PLC 2 DHII interface writes a code in the 10 through CF group whenever a remote or local fault bit is set ON The upper byte of the error code storage word Bits 10 17 stores a 2 digit HEX value This value gi
98. t the confusion that can result if you attempt to control a bit directly from both an output energize instruction and a write bit command Figure 5 25 gives an example of an indirect programming technique used to control Bit 01001 Here Storage Bit 12104 is controlled by a write bit command This bit is then examined by the program to control the status of Bit 01001 Note that Output Bit 01001 cannot be directly addressed by the write bit command However by controlling the storage bit and examining that storage bit in the program the desired effect is achieved Figure 5 25 Storage Bit Control Use Example A Original Rung Control of this output desired However bit already addressed by Input output instruction Output 111 010 13 01 B Recommended Technique Input Output 111 010 jii o 13 01 Storage Bit Control this bit through bit writ Jf a ontrol this bit through bit write F command to Control Output 01001 The second restriction listed here applies to all PLC 2 family processors For these processors when the node interface receives write bit commands it manipulates the 8 bit byte of the 16 bit memory word in which the addressed bit is located This may be the low byte containing Bits 00 07 or the high byte containing Bits 10 17 Should program instructions control other bits within the same byte there is a remote possibility that the PLC 2 DHII interface may write over programmed
99. t unique link address Yellow Check cabling on Data Step 6 Highway II link Communication on Data Highway II link OK Check cabling to the host device 6 13 Chapter 6 Operation and Troubleshooting Error Codes You ll find a complete list of error codes in Appendix B of this manual Chapter Summary In this chapter we gave you information about individual indicators and switches as well as procedures for using them to operate the interface We also provided procedures for troubleshooting and for replacing faulty boards Specifications Appendix Specifications Function Interfaces a PLC 2 programmable controller with Data Highway II Installation Standalone Mounting with Independent Power Supply Program Panel Interconnect Cable Cat No 1772 TC Data Highway Processor Cable Cat No 1771 CR Communication Rate megabit per second over Data Highway Cabling RG 11 Type Coaxial Cable for Data Highway II See Publication 1779 6 3 1 Option for Data Highway II Cabling Redundancy Power Requirements 15 115V AC 0 75 230V AC 47 63 Hz Programming Ladder Diagram Symbols Ambient Temperature Operation 09C to 60 C 32 F to 140 F Storage 40 C to 85 C 40 F to 185 F Humidity Rating 5 to 95 without Condensation A 1 Chapter Objectives Error Codes Appendix Error Codes This appendix lists error codes
100. terface to the Data Highway II link to communicate with other nodes on the Data Highway link Figure 2 5 Figure 2 5 shows three such devices each communicating through a local host interface link and node interface to a Data Highway II link Acomputer is shown communicating with other nodes of the Data Highway II link through an RS 422 449 link and a 1779 KFM interface A 1779 KFM interface has a single RS 422 449 channel that links an RS 422 449 compatible device to the Data Highway II link An 8200 CNC is shown communicating with other nodes through its Factory Communication Module Cat No 8200 KDHW an RS 422 link and a 1779 KFL interface A dumb terminal is shown communicating with other nodes through an RS 232 C link and a 1779 KFL interface Each 1779 KFL interface has two channels for connection to two host devices at the same time Through either channel it can interface either an RS 232 C compatible device or an RS 422 compatible device to the Data Highway II link You can use a host device to communicate through either an RS 232 C or RS 422 link to a 1779 KFL interface or an RS 422 449 link to a 1779 KFM interface in a packet assembler disassembler PAD protocol The PAD protocol is useful for communicating with robots and dumb terminals A dumb terminal can only communicate across a Data Highway II network through the PAD protocol because the terminal does not have the intelligence to assemble or disassemble message pa
101. these fault bits within their respective bytes corresponds directly to the position of start and done bits for that command Remote and local fault bits are controlled by the PLC 2 DHII interface The PLC 2 DHII interface sets a fault bit ON when a command cannot be executed due to a hardware related fault either between nodes or between the remote node interface and its host processor Figure 5 12 summarizes the significance of these bits A remote fault bit indicates that the remote node interface received a message but could not communicate with its host processor to execute that command A local fault bit indicates that the local node has not received a response from the remote node to acknowledge that it received a valid command 5 19 Chapter 5 Programming the Local Host 5 20 Figure 5 12 Remote Local Fault Bit Significance Processor ee oe eS gt CG j Local Fault D Possible Sources Power Off at Remote Node Interface d e Unused Remote Node Number Addressed EET Node Interface at Local or Remote Node Has a Disconnected Itself as a Result of Link 8 Monitoring 2 aa e Automatic Timeout at Local Node 000 1050 8 a Lo Lo D
102. tical Chapter 5 Programming the Local Host Programming Preset Code You enter the timeout preset code in the header rung of the communication zone of program The address field of the second GET instruction and the optional third GET for a time critical timeout in this rung is used for the timeout preset code Figure 5 23 shows the position of this rung element The address in a GET instruction is an octal number Because only octal values can be entered for this address the timeout preset value is a code that you must compute as outlined in this section The timeout preset is not a critical value For most applications a 5 second preset is acceptable The code for this timeout preset is 022 This code is used in all header rungs shown in this publication However there may be instances where another timeout preset interval is desired Table 5 B lists the 3 digit codes for intervals from 5 to 5 seconds The tolerance of this timer is plus 0 and minus 1 2 second A timeout preset code of 010 disables the timeout for those commands That means that in case of an error the done and fault bits will never be set With any other code the done or fault bit will be set within the specified timeout Table 5 B Timeout Preset Codes Timeout Interval Sec Code Message won t timeout It 010 waits indefinitely for a reply 5 011 1 0 012 1 5 013 2 0 014 2 5 015 3 0 016 3 5 017 4 0 020 4 5 021 5 0 022 5 37 Chapter 5
103. tinct advantages As the PLC 2 DHII interface continuously tries to send the command message any data content of the message for a write command is continuously updated As soon as the fault condition is corrected the message is sent with the latest data This eliminates the need for a manual reset of the start bit when a fault condition is corrected Once the command is completed the program automatically unlatches the start bit 5 27 Chapter 5 Programming the Local Host 5 28 ON OFF Input Status You can use the ON or OFF status of an input device to latch the start bit Figure 5 16 shows example rungs for this type of command initiation Figure 5 16 Status Initiated Command Remote Local Input Fault Fault Start 111 033 033 032 eph Co 11 12 02 12 In this example the rung is programmed to turn on the start bit when Input Bit 11111 is ON provided that both fault bits are OFF In normal operation the start bit is turned on by Input 11111 The fault bits initially are OFF This causes the PLC 2 DHII interface to format and send the command message Then when the command is completed the PLC 2 DHII interface turns on the done bit However unless a fault is detected Input Bit 11111 must go OFF to turn off the start bit in this example With this arrangement the command message is sent only once Input 11111 must be turned off then on again to execute this command a second time In normal operation the start
104. tion addressing a start bit Also you must end each command rung with an Energize Output 02707 element Figure 5 5 shows the format of a general command rung The second element in this general command rung is an EXAMINE ON The word address that you enter in this second EXAMINE ON element is the remote node designation General Command Code The bit pointer that you enter into this second EXAMINE ON element is the command code Figure 5 5 Through the command code you identify Priority Status of the Command as Time Critical or Supervisory Type of Command There are two general command rung formats which differ only in terms of the unit of memory which they control The general command rung formats are Block Command Format Bit Command Format 5 7 Chapter 5 Programming the Local Host Figure 5 5 General Command Rung Start Bit Remote Station AAA r 027 Refer to Figure 5 6 amp Figure 5 7 07 Command Code OX Supervisory 1X Time Critical 00 Protected Write Block with Reply 10 Protected Write Block with Reply 01 Read Block 11 Read Block 02 Protected Write Bit with Reply 12 Protected Write Bit with Reply 03 Unprotected Write Block w Reply 13 Unprotected Write Block w Reply 04 Unprotected Write Bit with Reply 14 Unprotected Write Bit with Reply 05 Protected Write Block VERIFIED 15 Protected Write Bit NO REPLY 06 Protected Write Bit VERIFIED 16 Protected Write Bit NO RE
105. tput indicator The indicator remains ON until the done bit is energized This then unlatches the output indicator in the second rung This example allows for the transience of the fault bits since the first rung need only be true once for the output indicator to be latched The method of Figure 5 21 can be extended to monitor multiple commands from a node controlling multiple output indicators as necessary However where more than one command is sent from a node the use of multiple output indicators may not be practical In this instance a single output indicator can be used to signal all remote or local fault conditions for commands from that node Figure 5 22 shows a method for fault indicator control assuming multiple commands Figure 5 21 Fault Bit Diagnostic Rungs Single Command Example 5 33 Chapter 5 Programming the Local Host Output Remote Fault Indicator 033 010 E ND 10 00 Local Fault 033 NAH levels 00 Output Done Indicator 032 010 JE 00 00 This example shows the fault bit monitoring for as many as eight commands The eight remote fault bits and the eight local fault bits reside in Word 033 In Rung 1 the status of the fault bits is compared to the constant zero The comparison controls an OFF delay timer The OFF delay timer begins to time when all the fault bits go OFF after one or more has been ON Bit 03015 the timed bit of the timer controls the output indicator As soo
106. ttaching the plugs on the ends of the cable segments Plugging the trunkline segments into the taps Cutting Cable Use RG 11 type coaxial cable for the trunkline When cutting the cable segments make them long enough to route them from one tap to the next with sufficient slack according to the guidelines in the section entitled Planning Your Cabling Configuration 3 11 Chapter 3 Installing Data Highway II Link Cabling Hardware Attaching Plugs After cutting the cable segments to the desired lengths attach a plug to each end of each segment Figure 3 13 illustrates the steps given here for attaching the plugs 1 Slide the plug sleeve over the end of the cable segment 2 Strip 0 7 inches of insulating jacket from the end of the cable segment exposing the braid 3 Strip 0 3 inches of braid and foil from the end of the cable segment exposing the insulation 4 Strip 0 2 inches of insulation from the end of the cable segment exposing the inner conductor 5 Push the plug pin as far as possible onto the center conductor of the cable 6 Use the crimping tool to crimp the plug pin onto the center conductor 7 Flare out the exposed end of the braid and tear off the exposed foil 8 Slide the plug body over the pin and cable end Make sure the neck of the plug body goes underneath the braid Push the plug body as far as possible onto the cable 9 Slide the plug sleeve down over the braid until it butts up
107. ver you may want to use the program to count the number of times a fault bit turns on and or to store the error code each time a fault bit turns on Because of the asynchronous relationship you may not be able to do these types of functions accurately by examining fault bits directly Instead of examining the fault bits directly use a GET PUT rung at the beginning of the program to copy the fault word into another word You can then examine the corresponding bits of the other word any time during the program scan to determine the status of the fault bits as copied at the beginning of the program scan Even though the PLC 2 DHII interface may change the state of fault bits in the middle of a program scan the status of the bits in the copy word will not change until the start of the next program scan Timeout Preset Value In addition to its remote local fault bit control you can have a timer for both supervisory time critical or a separate time for supervisory and time critical The second timeout time critical preset is entered after the first supervisory timer by using another GET instruction in the header rung By this the KP2 provides two automatic timers for monitoring command completion While they function automatically during PLC 2 DHII interface operation these timers use a preset value entered in the ladder diagram program This feature enables the PLC 2 DHII 5 35 Chapter 5 Programming the Local Host 5 36 interf
108. ves supplemental error or fault information depending on the type of error code displayed This value may have one of two meanings Reference Number Counter For Error Codes D2 through E7 the upper byte stores a 2 digit reference number This number points to the location of a programming error within the communication zone of the program This error may be an incorrect instruction or an improper address entered within a rung of the communication zone In this numbering scheme the header rung is designated as 00 Subsequent communication zone rungs are numbered sequentially Note that Error Codes D2 through E7 are intended as aids in start up debugging of the communication zone Thus the reference number stored in this word can be a valuable tool for debugging purposes Foe Error Codes 10 through CF the upper byte stores a 2 digit counter This counter shows the number of Error Codes 10 through CF written into the storage word by the PLC 2 DHII interface The counter increments each time the module enters a different error code Initiating and Monitoring Commands Chapter 5 Programming the Local Host Because Codes D2 through E7 are intended for start up situations and Codes 10 through CF are intended for situations subsequent to power up there is no conflict in controlling this upper byte of the error code storage word Error codes are generally used in the application program only for display They have special value
109. which the PLC 2 family processor can communicate Figure 2 10 Figure 2 10 Data Highway Link and a Data Highway II Link for a PLC 2 Family Processor Computer R8 422 449 Link PLC 2 05 4 000 Cable Feet Max Processor 1771 KA 1771 KFM Module Interface Data Highway II Data D y lt Highway Link 1771 KA2 1779 KP2 1779 KP2 Module Interface Interface PLC 2 30 PLC 2 20 Processor Processor Chapter Summary Now that you have been introduced to the PLC 2 DHII interface and concepts of how it communicates across a Data Highway II network you are ready to read about how to install the Data Highway II link cabling hardware 2 18 Chapter Objectives Identifying Hardware Installing Data Highway Il Link Cabling Hardware In this chapter we explain how to install cabling hardware for a Data Highway II link We tell you how to Identify Hardware Plan Your Cabling Configuration Install Taps Trunkline Droplines To install a Data Highway II link you need the following cabling hardware items Part A B Catalog Number Manufacturer Information RG 11 Type Coaxial Cable None Times Wire amp Cable AA 5066 Astro Wire amp Cable 20 111A Alpha 515780 Local Tap 1779 XP AMP 225886 6 One Dropline Cable Two Cable Plugs Crimping Tool None AMP 220015 1 Terminator 2 1779 XT None Do not use an unauthorized part An unautho
110. y transmitting a command message When a node transmits a command to read an immediate access block the node receiving the command immediately transmits a reply message while the initiating node still holds the token For any other command requiring a reply the node receiving the command must wait until it holds the token before it can transmit the reply message Some commands call for the node receiving the command message to transmit no reply message Chapter 2 Introducing the PLC 2 DHII Interface Reading a Block of Data You can generate two types of commands to read a block of data Read Block Read Immediate Access Block When a node interface receives a read block command from another node it reads the specified area of the host s memory then when it receives the token it transmits the reply message containing the block of data specified in the command For a node to reply to a command to read an immediate access block the host must periodically write a specified block of data from the host s memory into a buffer in the node interface When the node interface receives a command from another node to read an immediate access block it reads the specified block of data from its buffer and immediately transmits the reply message without waiting to receive the token Writing a Block of Data For write block commands you specify a block of data from the local host s memory that you want to write into a specified block of
111. y messages can be sent to any node in any link in a network Figure 2 5 In Figure 2 5 the PLC 3 processor and the computer are on a separate link also the PLC 2 15 processor the PLC 2 30 processor the 8200 CNC and the dumb terminal are on a second separate link The PLC 3 processor and computer can send time critical messages to each other but can send only supervisory messages to other nodes on other links Similarly the PLC 2 15 and PLC 2 30 processors can send time critical messages to each other but can send only supervisory messages to other nodes on other links You are limited to transferring 21 words maximum using a read immediate access block command and limited to transferring less using other time critical commands However the size of a supervisory message can be much greater depending on the type of command For example in Figure 2 5 the computer could upload the memory of any PLC processor in blocks of 244 bytes Chapter 2 Introducing the PLC 2 DHII Interface Generated Commands You can program the PLC 2 DHII interface to generate the following types of commands Read Commands Read Block Write Bit Commands Protected Write Bit with No Reply Protected Write Bit with Reply Unprotected Write Bit with Reply Protected and Verified Write Bit Write Block Commands Protected Write Block with No Reply Protected Write Block with Reply Unprotected Write Block with Reply Protected and Verif
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