Rockwell-automation 1775-KA PLC-3 Communication Adapter Module User Ma Manual de usuario

User ManualPLC-3CommunicationAdapter Module(Cat. No. 1775-KA)AllenBradley

IntroductionChapter 116Table 1.C lists the specifications for the 1775–KA module.Table 1.CModule SpecificationsFunctionInterface the PLC-3 Processorw

Chapter 991Computer to PC CommunicationThis chapter and the chapters that follow (10,11, and 12) described how towrite a software driver that enables

Computer to PC CommuniationChapter 992 data link – checks the path between stations for errors to ensure thatdata is transmitted in a proper sequence

Computer to PC CommunicationChapter 993Figure 9.1The Application and Network LayersCMD STS FNC ADDR DATADST SRC CMD STS TNSData(From Application Laye

Computer to PC CommuniationChapter 994Figure 9.2The Application, Network and Data Link Layer of RS-232-C Communication (Full orHalf-Duplex)CMD STS FN

Computer to PC CommunicationChapter 995We use the term protocol to describe the relationship between two similarlayers at two different stations. The

Chapter 10101Full-Duplex ProtocolIf you are connecting the 1775–KA module to another Allen–Bradleycommunication interface module (such as a 1771–KG,

Full-Duplex ProtocolChapter 10102In general, full–duplex protocol gives higher data throughput, but it canhandle communication between only two peer

Full-Duplex ProtocolChapter 10103Additionally, a block check character (BCC) is used at the end of eachpacket for error checking. These bytes can be

Full-Duplex ProtocolChapter 10104 DLE ACK – signals that the receiver has successfully received the lastmessage sent. DLE NAK – signals that the re

Full-Duplex ProtocolChapter 10105Block CheckThe block check character (BCC) is a means of checking the accuracy ofeach message packet transmission.

IntroductionChapter 117Figure 1.2Example Data Highway ConfigurationPCPCPCPCPCAllen-BradleyData Highway1775-KA ModuleNOTE: All PCs are Allen-BradleyU

Full-Duplex ProtocolChapter 10106The BCC algorithm provides a medium level of data security. It cannotdetect transposition of bytes during transmiss

Full-Duplex ProtocolChapter 10107Figure 10.3Software Implementation of Data PathsTransmitterB AReceiverPath 1Path 2Transmitter BARe

Full-Duplex ProtocolChapter 10108We could show paths 2, 3, and 4 in a similar way.The full–duplex protocol is symmetrical; that is, anything that we

Full-Duplex ProtocolChapter 10109Whenever the receiver has received a link packet successfully, it attemptsto give the network packet portion (link l

Full-Duplex ProtocolChapter 101010timeout, and waits for a response on path 2. You can use the diagnosticset timeout command to set this timeout per

Full-Duplex ProtocolChapter 10101110044-IDLE STX Data DLE ETX BCCMessage PacketTRetransmit Same MessageTimeout LoopReceivedYesTNoReceivedYes3*NoYesPY

Full-Duplex ProtocolChapter 101012Table 10.ATransmitter for Full-Duplex ProtocolTRANSMITTER is defined asloopMessage=GET-MESSAGE-TO-SENDStatus=TRANSF

Full-Duplex ProtocolChapter 101013Receiver ActionsSince the receiver gets “dirty” input from the physical world, it is morecomplex and must be capabl

Full-Duplex ProtocolChapter 101014overflows, the receiver continues summing the BCC, but it discards thedata.The receiver also sets an error flag to

Full-Duplex ProtocolChapter 101015Figure 10.8Receiver for Full-Duplex ProtocolRCVE CHARLAST = NAKReceiveMessage ?LAST = ACKLAST = NAKSend DLE LA

IntroductionChapter 118The PLC–3 can support multiple 1775–KA modules in the same PLC–3chassis. This provides the PLC–3 with concurrent access to sev

Full-Duplex ProtocolChapter 101016Table 10.BReceiver for Full-Duplex ProtocolRECEIVER is defined asvariablesLAST-HEADER is 4 bytes copied out of the

Full-Duplex ProtocolChapter 101017 begin GET-CHAR if char is a DLE begin add char to BCC return a

Full-Duplex ProtocolChapter 101018Figure 10.10 shows a DLE NAK response to the initial messagetransmission. After the message is retransmitted, a DL

Full-Duplex ProtocolChapter 101019Figure 10.11Message Transfer with Timeout and ENQNot FullDLE ACKOKxxxxDLE ENQxxxxSOURCE XMTR LINK RCVR SINK1004

Full-Duplex ProtocolChapter 101020Figure 10.12 Message Transfer with RetransmissionNot FullDLE NAKOKxxxxDLE ENQxxxxSOURCE XMTR LINK RCVR SINK1004

Full-Duplex ProtocolChapter 101021Figure 10.13Message Transfer with Message Sink FullNot FullOKxxxxxxxxSOURCE XMTR LINK RCVR SINK10050–IDLE NAKDLE

Full-Duplex ProtocolChapter 101022If you were to connect a line monitor to the wires between station A andB, and only the A to B subsystem were activ

Full-Duplex ProtocolChapter 101023Embedded Response OptionTo simplify the design of the receiver in some cases, you can disabletransmission of embedd

Chapter 11111Half-Duplex ProtocolHalf–duplex protocol serves as an alternate to full–duplex protocol. Half–duplex is synonymous with polled–subscrib

Half-Duplex ProtocolChapter 11112You must program a computer to serve as a master that controls whichstation has access to the link. All other stati

Chapter 221InstallationThis chapter describes installation of the 1775–KA module in two phases: Installing hardware Programming configuration paramet

Half-Duplex ProtocolChapter 11113These ASCII control characters are extended to 8 bits by adding a zero forbit 7. See ANSI X3.4, CCITT V.3, or ISO 6

Half-Duplex ProtocolChapter 111141775–KA is just one of several stations on a Data Highway, the STNtogether with the DST identifies the 1775–KA stati

Half-Duplex ProtocolChapter 11115Figure 11.1Formats for Half-Duplex ProtocolDLE ENQ STN BCCa) Polling PacketCMD STS FNC ADDR DATADST SRC CMD STS TNSD

Half-Duplex ProtocolChapter 11116Block CheckThe block check character (BCC) is a means of checking the accuracy ofeach packet transmission. It is th

Half-Duplex ProtocolChapter 11117Each station on the multidrop link must contain a software routine, knownas a transceiver, that can both transmit an

Half-Duplex ProtocolChapter 11118Figure 11.2Slave TransceiverSoftwareSoftwareHardwareSOURCENetworkPacketNetworkPacketOKFullTRANSMITTER RECE

Half-Duplex ProtocolChapter 11119The master should poll each slave repeatedly until that slave hastransmitted all of its messages. The master should

Half-Duplex ProtocolChapter 111110Figure 11.3Implementation of Half-Duplex ProtocolXCVRSelect StationPoll Selected StationStart TimeoutReceiveNoRecei

Half-Duplex ProtocolChapter 111111Transceiver ActionsSince the transceiver receives “dirty” input from the physical world, itmust be capable of respo

Half-Duplex ProtocolChapter 111112compares the SRC, CMD, and both TNS bytes with the correspondingbytes of the previous message received. If these b

InstallationChapter 222Figure 2.1Front View of 1775-KA Module10003-IXMTGRCVGRDYERRDISSelf–Test IndicatorsThumbwheel SwitchRS–232–C port IndicatorsDat

Half-Duplex ProtocolChapter 111113When the slave transceiver receives a DLE NAK, it takes messages fromthe source until the source is empty. It disc

Half-Duplex ProtocolChapter 111114Figure 11.5 shows a message transfer in which the BCC was invalid.After a timeout, the message is retransmitted. A

Half-Duplex ProtocolChapter 111115Figure 11.6 shows a message transfer in which the acknowledgment wasdestroyed by noise. After a timeout, the messa

Half-Duplex ProtocolChapter 111116Figure 11.8 shows a slave being polled, and answering with a message.Because a block check error is found, the mast

Half-Duplex ProtocolChapter 111117 If each station is polled only once per cycle, the master must keep arecord of the first 6 link–level data bytes

Half-Duplex ProtocolChapter 111118Figure 11.10Message Sink Full, Case 1FullOKxxxxxxxxSINK MASTER LINK SLAVE SINK10060–IDLE ACKSOURCE/ SOURCE/BCCDLE

Half-Duplex ProtocolChapter 111119When a slave station’s message source and sink share a common memorypool (as in the 1775–KA module) it may be that

Half-Duplex ProtocolChapter 111120When monitoring half–duplex protocol on a two–wire link, you need tomonitor only one line. the example below shows

Chapter 12121The Network and Application Layer ProtocolThe network protocol defines a network packet format for interactionbetween application progra

Network and Application Layer ProtocolsChapter 12122Network ModelTo implement your Data Highway network layer software, use a routingsubroutine and a

InstallationChapter 223CAUTION: To guard against unpredictable operation of thePLC–3 processor, do not change the setting on any thumbwheelswitch whi

Network and Application Layer ProtocolsChapter 12123Network Packet FieldsAs we discussed the communication protocol used on the data link, wedescribe

Network and Application Layer ProtocolsChapter 12124Figure 12.3Reply Message Packet FormatCMD STS DATADST SRC CMD STS TNSData(From Application Layer)

Network and Application Layer ProtocolsChapter 12125If the network layer of your computer cannot deliver a command toanother station, it writes a loc

Network and Application Layer ProtocolsChapter 12126message. During an upload or download, the TNS value is the only wayto distinguish between the p

Network and Application Layer ProtocolsChapter 12127 Word Offset TOTAL TRANS (total transaction size)Appendix A lists the message formats (command an

Network and Application Layer ProtocolsChapter 12128Table 12.AThe commands that the PLC-3 can send and/or receive, and the hexadecimal values for the

Network and Application Layer ProtocolsChapter 12129Remote errors mean that a command was successfully delivered by thenetwork, but the remote statio

Network and Application Layer ProtocolsChapter 121210ADDR (address)The address field in command messages can be in one of the followingformats: PLC/P

Network and Application Layer ProtocolsChapter 121211Figure 12.4PLC/PLC-2 Data Table Byte Addressing765432107654321010065–ILeast Significant ByteTran

Network and Application Layer ProtocolsChapter 121212For level:The default address is:13 (data table)21 (Current context)All others0You must always s

InstallationChapter 224Table 2.A1775-KA Switch SettingsIf thisswitch: Is: Then1 OPENthe PLC will switch over to backup whenever one of thefollowing f

Network and Application Layer ProtocolsChapter 121213Figure 12.5Example of PLC-3 Logical Addressing Format65432100 1110066–I10 0000 0000 1011 1111 11

Network and Application Layer ProtocolsChapter 121214The symbolic addressing format applies to PLC–3 type commands(Table 12.A, appendix A) transmitte

Network and Application Layer ProtocolsChapter 121215In this format, A1 through A24 represents the 1 to 24 bits of the physicaladdress. For example,

AppendixAA1Message FormatsThis appendix presents the detailed message formats for each type ofcommand and reply message that the PLC–3 can send and/o

Message FormatsAppendix AA2*Use these commands to affect only the RS–232–C port of the 1775–KAmodule.Important: In the formats shown in this section,

Message FormatsAppendix AA3Figure A.1Cabling for a RS-232-C Line Monitor12345678202525 Pin, FemaleRS-232-C Connector25 Pin, MaleRS-232-C Connector25

Message FormatsAppendix AA4Figure A.2A RS-232-C Link Configuration that includes a line monitor10069-I1775KAPLC3 CommunicationAdapter ModuleToggle

Message FormatsAppendix AA5Table A.AASCII Codes and Their Numerical ValuesHexBinary ASCII Display[1] Hex Binary ASCIIDisplay [1]00 0000000 NUL NU2A 0

Message FormatsAppendix AA6230100011 # (none) 4D 1001101 M (none)24 0100100 $ (none) 4E 1001110 N (none)25 0100101 % (none) 4F 1001111 O (none)26 010

Message FormatsAppendix AA7HexBinary ASCII Display[1] Hex Binary ASCII Display[1]55 1010101 U (none) 6A 1101010 j (none)56 1010110 V 6B 1101011 k57 1

InstallationChapter 225IndicatorsThere are three sets of LED indicators on the front of the 1775–KAmodule (Figure 2.1). The first group, labeled SELF

Message FormatsAppendix AA8Figure A.3Typical monitor display and how it is interpretedSB8NNAKNUUEXDLEXDLAKXSULD>{{{{{{{{{{{{DLESTX DST SRC CMD STS

Message FormatsAppendix AA9data table memory. Put the low byte (lest significant bits) of the PCaddress value into the first byte of the ADDr field.

Message FormatsAppendix AA10Command Format:DLESRC C 0STNSMD0TSTNS ADDRSTXDLE ETXBCCDATA - Max of 243 bytesReply Format:DST SRCC STNSMD TSTNS40DLE S

Message FormatsAppendix AA11DLESRC C 0STNSMD5TSTNSADDRSET RESETUp to 61 masks of this formSTXDLE ETXBCCReply Format:DST SRCC S TNSMDTS TNS45DLE ST

Message FormatsAppendix AA12Unprotected ReadUse this command to read words of data from any area of PC data tablememory. Use the SIZE field to speci

Message FormatsAppendix AA13PLC–3 stations can receive any of the commands in the basic commandset and execute them within a specified file in the PL

Message FormatsAppendix AA14B. File symbol address plus word offsetDLESRC C 0STNSMDFTSTNSSTXFNC 0002ASCII sumbol(8 characters max)DLE ETXBCC00W/F01

Message FormatsAppendix AA15Word Range ReadUse this read command with a word symbol, a file symbol plus a wordoffset, or a block address as a startin

Message FormatsAppendix AA16B. Format when reporting an errorDLESRCSTX DST C 4FSTNSMDTSTNSDLE ETXBCCETXST SWhere the extended status byte is option

Message FormatsAppendix AA17Reply Format:This is the same as the reply packet format for all writes.A. Format when successful execution.DLESRCSTX DS

InstallationChapter 226Data Highway Cable ConnectionsThere are two cable connectors, or ports, on the front of the 1775–KAmodule (Figure 2.1). The b

Message FormatsAppendix AA18Reply Format:This is the same as the reply packet format for all reads.A. Format when the command was successfully execu

Message FormatsAppendix AA19File WriteUse this write command with either a file symbol or a block address as astarting address. This starting addres

Message FormatsAppendix AA20Where the extended status byte is optional.A PLC–3 receives privileged commands from an RS–232–C device (suchas a compute

Message FormatsAppendix AA21Privileged WriteUse this write command with a PLC–3 physical address as a startingaddress. You use this command to downl

Message FormatsAppendix AA22Command Format:FNCDLESRCSTX DST C 0FSTNSMDTSTNSDLE ETXBCC07Reply Format:A. Format when the command was successfully exe

Message FormatsAppendix AA23Reply Format:A. Format when the command was successfully executedDLESRCSTX DST C 4FSTNSMDTSTNSDLE ETXBCCB. Format when

Message FormatsAppendix AA24B. Format when reporting an errorETXST SDLESRCSTX DST C 4FSTNSMDTSTNSDLE ETXBCCWhere the extended status byte is option

Message FormatsAppendix AA25Diagnostic Counters ResetUse this command to reset to zero all the diagnostic timers and counters inthe station interface

Message FormatsAppendix AA26Diagnostic ReadYou use this command to read up to 244 bytes of data from the PROM orRAM of the station interface module.

Message FormatsAppendix AA27Table A.BContents of Status DATA for 1775-KA ModulesByte Meaning1Operating status of PLC-3 processor:Bits 0 to 1:0 = Prog

InstallationChapter 227 Interfacing a PLC–3 controller with a computer, either directly orthrough modems (Figure 2.4)Figure 2.4Linking a PLC-3 Stati

Message FormatsAppendix AA28Byte Meaning7,8Starting byte address of the diagnostic counters and timers. There is a separate block of diagnostic time

Message FormatsAppendix AA29Set NAKsUse this command to set the maximum number of NAKs that the stationinterface module will accept per message trans

Message FormatsAppendix AA30Set VariablesUse this command to set the timeout and maximum NAKs, and ENQs allat once. Put the timeout in the first byt

AppendixBB1Error CodesThis appendix describes the error codes that the 1775–KA module willreport. Errors are of three types: local reply remoteThe 1

Remote Error Codes Received from the1773-KA ModuleAppendix BB2These codes are sent by the 1775-KA: This error code is then stored atthe command stati

Remote Error Codes Received from the1773-KA ModuleAppendix BB3When a remote station transmits a command, the local 1775–KA modulemight issue a reply

Remote Error Codes Received from the1773-KA ModuleAppendix BB4Local and Reply Error Code Listing for the PLC–3 ProcessorError ErrorCode Type Meaning3

Remote Error Codes Received from the1773-KA ModuleAppendix BB5ErrorErrorCode Type Meaningnumber of bytes after the TNS is not amultiple of 4.For PLC/

Remote Error Codes Received from the1773-KA ModuleAppendix BB6ErrorErrorCode Type Meaningshutdown request to the local PLC-3 processorFor all PLC-3 r

Remote Error Codes Received from the1773-KA ModuleAppendix BB7ErrorErrorCode Type Meaning destination PLC-3 file.3.The length of the destination fil

Introduction 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General 11. . . . . . . . . . . . . . . . . . . . . . . .

InstallationChapter 228 Interfacing a PLC–3 controller with a remote Data Highway through amodem link (Figure 2.5)Figure 2.5Linking a PLC-3 Station

Remote Error Codes Received from the1773-KA ModuleAppendix BB8ErrorErrorCode Type Meaningerror will occur if a procedure name is used inplace of a sy

Remote Error Codes Received from the1773-KA ModuleAppendix BB9ErrorErrorCode Type Meaningdoes not have access privileges (namely, majorsection 0, 1,

Remote Error Codes Received from the1773-KA ModuleAppendix BB10ErrorErrorCode Type Meaning169 localEither the number or the expression following the&

Remote Error Codes Received from the1773-KA ModuleAppendix BB11ErrorErrorCode Type Meaning207 local Word range specified in destination address.208 l

Remote Error Codes Received from the1773-KA ModuleAppendix BB12ErrorErrorCode Type Meaning231 replyFor all PLC-3 read and write commands:There is an

Remote Error Codes Received from the1773-KA ModuleAppendix BB13ErrorErrorCode Type Meaning4.First word of destination location does not exist.237 rep

Remote Error Codes Received from the1773-KA ModuleAppendix BB14If the remote station has a 1771–KG, 1771–KA, or 1774–KA module, theremote error codes

Remote Error Codes Received from the1773-KA ModuleAppendix BB15ErrorCode MeaningIt indicates that either a very heavy traffic load is beingpresented

Remote Error Codes Received from the1773-KA ModuleAppendix BB16ErrorCode Meaning Improper command may return this error code* EEPROM bad* No re

AppendixCC1Diagnostic Counter BlockAt thisbyte offset:This counter is stored:1.Bad CRC on acknowledgement [2] (Local error A')2.No acknowledgme

InstallationChapter 229 Interfacing a PLC–3 controller to a PLC–2 Family processor through a1771–KG module in a point–to–point link (Figure 2.6)Figu

Diagnostic Port CountersAppendix CC2At thisbyte offset:This counter is stored:1,2.Command messages sent3,4.Reply messages received5,6.Command messag

AppendixDD1Detailed FlowchartsThe flowcharts in chapter 10 and 11 give a simplified view of an exampleof software logic for implementing full–duplex

Detailed FlowchartsAppendix DD2Figure D.2Transmitter Routine for Full=-Duplex ProtocolXMITGETMSGGet Messagefrom Network LayerReset NAKand Timeout

Detailed FlowchartsAppendix DD3Figure D.3Receiver Routine for Full-Duplex ProtocolRCVEGET BUFFERGet a BufferLAST = NAKReset Receiver Error FlagGET CO

Detailed FlowchartsAppendix DD4Figure D.4WTAK SubroutineRETURNGet the Response Code (if Any) From RESPSTOPTIMECancel theACK TimerCommon:• WT

Detailed FlowchartsAppendix DD5Figure D.5SENDM SubroutineRETURNBCC IncludeETX in BCCLink Data Done ?BCC IncludeByte in BCCSENDDATASend Li

Detailed FlowchartsAppendix DD6Figure D.6STARTTIME Subroutine10076–ISTARTTIMERETURNAn Implementation DependantRoutine that Schedules TIMEOUT to Be Ex

Detailed FlowchartsAppendix DD7Figure D.8TIMEOUT Subroutine10078–ITIMEOUTRETURNScheduled By:•Aborted By:•WAKEUPWake Up the ProcessSleeping at WTRESP(

Detailed FlowchartsAppendix DD8Figure D.9GETMSG SubroutineGETMSGRETURNUNLINKRemove aMessage FromQueueBoxed area above must be executedindivisibly, i.

Detailed FlowchartsAppendix DD9Figure D.10SIGOK/SIGFAIL SubroutineSIGOK Place SuccessCode in Message Control BlockLINKPlace Message on RETURN Queu

InstallationChapter 2210 Interfacing a PLC–3 controller as a slave station on a multipointmodem link (Figure 2.7)Figure 2.7Linking a PLC-3 to a Mult

Detailed FlowchartsAppendix DD10Figure D.11 shows the transmitter (XMIT) and receiver (RCVE) routinessharing the transmit side of the UART. XMIT tran

Detailed FlowchartsAppendix DD11Figure D.12SENDCTL SubroutineSENDCTLTXALLOCAllocate VART or WaitSENDTransmit DLESEND TransmitControlCodeTXFREED

Detailed FlowchartsAppendix DD12Figure D.13SENDTX SubroutineSENDTXTXALLOCAllocate UART or WaitSENDTransmit DLESENDTransmit ETX Zero Out AnyPre

Detailed FlowchartsAppendix DD13Figure D.14SEND SubroutineSENDDisable Processor Interrupts Enable UARTTransmit Interrupt UARTTransmitter

Detailed FlowchartsAppendix DD14Figure D.15SENDDATA SubroutineSENDDATATXALLOCAllocate UART or WaitSENDTransmit Link Data Byte Is DataByte DLE

Detailed FlowchartsAppendix DD15Figure D.16TXALLOC Subroutine10086-ITXAL-LOC UARTIn Use ?Set IN–USE FlagRETURNSLEEPWait at TXALWTUntil UART i

Detailed FlowchartsAppendix DD16Figure D.18TRANSMIT INTERRUPT Subroutine10088-IWAKEUPTRANSMITINTERRUPTINTERRUPTRETURNResume ProcessSleeping AtTXWAITN

Detailed FlowchartsAppendix DD17Figure D.20SLEEP and WAKEUP InteractionPROCESS A PROCESS B PROCESS CSLEEPA Previous WakeupLaterWAKEUP21783465NOTE:

Detailed FlowchartsAppendix DD18WAKEUP without losing immediate control of the processor. If B wakesup A, context switching would be deferred until

Detailed FlowchartsAppendix DD19Figure D.22Message QueueFIRSTLASTNEXTMESSAGESIZESTATUSNetwork Data BlockNEXTMESSAGESIZESTATUSNetwork Data Blo

InstallationChapter 2211Each mode of operation requires a different communication protocol. Theunpolled mode uses full–duplex protocol (chapter 10)

Detailed FlowchartsAppendix DD20Figure D.24LINK SubroutineRETURNAn ImplementationInput:LINK10094–IAddress of Queue Message BlockDependent Routinethat

Detailed FlowchartsAppendix DD21Figure D.25XMSG SubroutineXMSGGETBUFCheck Availabilityof Receive BufferClear BCCAccumulatorGETCODEGet a CodeLink Data

Detailed FlowchartsAppendix DD22Figure D.26GETCODE SubroutineGETCODEGETRAWGet Byte From UARTDLE ?GETRAWGet Byte From UARTDLE ?NoYesBCCAdd Data Byte

Detailed FlowchartsAppendix DD23Figure D.27GETRAW SubroutineGETRAWDisable Processor Interrupts Enable UARTReceive InterruptByte inUART ? Di

Detailed FlowchartsAppendix DD24Figure D.28Receive Interrupt Subroutine10098-IWAKEUPRECEIVEINTERRUPTINTERRUPTRETURNNOTE: of a Z80 S10This figure ass

Detailed FlowchartsAppendix DD25Figure D.30GETBUF SubroutineGETBUFIs therea Buffer ?GETFREE Get anEmpty BufferRETURNYesNoIs therea Buffer

Detailed FlowchartsAppendix DD26Figure D.31GETFREE Subroutine10101–IGETFREERETURNAn Implementation Dependent Routine to Try to Allocate anEmpty Messa

Symbols**Empty**, 224AAddresses, 43, 45Addressing rules, 41addressing a file, 47addressing a word, 48, 411addressing a word range

IndexI–2Half-duplex protocolblock check, 116link-layer packets, 114multidrop link, 111transmission codes, 112Hardware Installation, 21

Publication 17756.5.1 - October, 1992Supersedes 1775-6.5.1 January 1985AllenBradley, a Rockwell Automation Business, has been helping its customers

InstallationChapter 2212Table 2.CDistance Rate VariationsDistancein feetMaximumBaud Rate1,000 19,2002,000 9,6003,000 9,6004,000 4,8005,000 4,8006,000

InstallationChapter 2213PinoutThe necessary RS–232–C port connections are described in Table 2.Dbelow:Table 2.DRS-232-C Port ConnectionsSignal at the

InstallationChapter 2214sequence. Some modem will not respond to DTR until the phone rings,while others will always pick up the phone whether it is r

InstallationChapter 2215Figure 2.8Connection to Allen-Bradley 1771-KG or 1771-KE/KF Module1273254568201313214456811Connect the Shield at One End Only

InstallationChapter 2216Figure 2.9Connection to Allen-Bradley 1775-KA Module127325456820132527456820Connect the Shield at One End OnlyRS–232–CCHANNEL

InstallationChapter 2217Figure 2.10Connection to user-Supplied Modem or RS-232-C Device12345678202510011–I1User–suppliedModerm orRS–232–CDeviceProtec

Table of ContentsiiMessage Procedure Commands 61. . . . . . . . . . . . . . . . . . . . General 61. . . . . . . . . . . . . . . . . . . . . . .

InstallationChapter 2218DTR, DSR, and DCD signals. It incorporates timeouts and tests toproperly operate these types of modems. Auto–answer: these

InstallationChapter 2219The transmission format may be summarized as follows:start bitdata bit 0data bit 1data bit 2data bit 3data bit 4data bit 5dat

InstallationChapter 2220Figure 2.11LIST Menu for 1775-KA ModuleSystem Mode1 Test–Monitor2 Run Monitor3 Program Load4 Remote Enable5 System Statu

InstallationChapter 2221You access the LIST function by typing the word LIST and press theENTER key. After accessing the LIST function, select option

InstallationChapter 22223 ACCEPT UPLOAD/DOWNLOAD4 ACCEPT WRITES5 BACKUP OPERATION6 PLC–2 MASKENTER NEXT>This menu allows you to select options tha

InstallationChapter 2223Send UnprotectedThis option determines whether or not the 1775–KA module will be ableto send unprotected command messages to

InstallationChapter 2224keyswitch is on. At initial power–up, the module enables the ACCEPTWRITES option by default.Backup OperationThis option det

InstallationChapter 2225This menu allows you to select options that apply to only the DataHighway port of the 1775–KA module. These options are desc

InstallationChapter 22265 EVEN PARITY6 SEND EMBEDDED RESPONSESENTER NEXT>This menu allows you to select options that apply to only the modem porto

InstallationChapter 2227Communication ModeThis option determines whether the RS–232–C port of the 1775–KAmodule can operate in a half–duplex (polled)

Table of Contents iiiThe Network and Application Layer Protocol 121. . . . . . . . . . . Network Layer 121. . . . . . . . . . . . . . . . . . .

InstallationChapter 2228module must have its own unique station number. If you want to send thesame message through both 1775– KA modules, you must

InstallationChapter 22292. Use the LIST function to disable the modem and Data Highwayports.3. Use the LIST function to select BACKUP OPERATION for b

InstallationChapter 2230Figure 2.12How addresses of the primary and backup PLC-3 controllers change during switchover.Before switchover: Primary PCL–

InstallationChapter 2231Using Manual SwitchoverAfter you select the BACKUP OPERATION for a rev. D. (or later)1775–KA module, you may choose to use

InstallationChapter 2232Figure 2.13Example of a Rung that Sends a Message during switchover from primary PLC-3 to backupPLC-3.ENMSGMESSAGE TYPECTL

InstallationChapter 2233If an automatic switchover occurs:And: Then:the PLC-3 processor is waiting for aresponsethe response is ignoredanother statio

Chapter 331Data Highway CommunicationThis chapter introduces some of the concepts and terminology involvedwith operating the 1775–KA module of the Da

Data Highway CommunicationChapter 332A command message either gives (writes) data to, or requests (reads)data from, one station to another. A reply m

Data Highway CommunicationChapter 333To enter a message instruction, complete the steps below:1. Enter a condition that, when true, will activate the

Data Highway CommunicationChapter 3342. Press the message instruction key.3. Specify message type 1.4. Choose a control file word where status inform

Chapter 111IntroductionThe PLC–3 Communication Adapter Module (cat. no. 1775–KA) is anoptional module used in the PLC–3 main chassis or expander chas

Data Highway CommunicationChapter 335When the rung becomes true, the message instruction begins sendingcommand(s) across the Data Highway. At the sam

Data Highway CommunicationChapter 336The whole purpose of Data Highway communication is to transfer datafrom one station processor memory location to

Data Highway CommunicationChapter 337Figure 3.3Two Ways to Use 1775-KA CommandsSTATMSGMESSAGE TYPE 1STAT1001201STATCTL = FB200:0000=200CHANNEL: E2.5.

Data Highway CommunicationChapter 338Access privilegesNot every Data Highway station can read or write to every other station.In general, read and wr

Data Highway CommunicationChapter 339A PLC–3 station can read from any part of a PLC/PLC–2 data table.However, A PLC– 3 station cannot write to a PLC

Data Highway CommunicationChapter 3310PLC/PLC–2 station numbers are octal, while PLC–3 input files havedecimal addresses. This means that PLC–3 input

Data Highway CommunicationChapter 3311PLC–4 StationsTo read or write to a PLC–4 station, you can send either protected orunprotected commands.Switche

Chapter 441Addressing Rules and ExamplesThis chapter presents some general rules for specifying data addresses inmessage procedures. This chapter ass

Addressing Rules and ExamplesChapter 442An expression can be used in place of any of the above fields in anaddress.Within the above listed fields of

Addressing Rules and ExamplesChapter 443Data is referenced by its address in memory. In a message procedure, youmust precede an address with a dolla

IntroductionChapter 112 Chapter 10 – describes how to write a full–duplex line driver to enablea computer to communicate to the 1775–KA’s RS–232–C ch

Addressing Rules and ExamplesChapter 444You can also use symbols to represent data and data addresses in messageprocedures. A symbol can consist of

Addressing Rules and ExamplesChapter 445Figure 4.4Symbol TypesUser SymbolGenerate this symbolicvalue through theassignment commandSymbolSystem Symbol

Addressing Rules and ExamplesChapter 446A symbolic address is another way of representing the logical address ofdata (section titled Addresses). You

Addressing Rules and ExamplesChapter 447The PLC–3 processor uses logical addresses to reference data in memory.No PLC–3 address is valid unless it me

Addressing Rules and ExamplesChapter 448For PLC–3 timer and counter files, it is important to note that the datawords are stored in the following ord

Addressing Rules and ExamplesChapter 449<wordaddr><filesym>:<offset><wordsym>Note that <wordaddr>is interpreted as an o

Addressing Rules and ExamplesChapter 4410Figure 4.6Example of Addressing Specific Bits in PLC-3 Memory@FILE_A:16/8<Bit number 8 (decimal)Delimiter

Addressing Rules and ExamplesChapter 4411Figure 4.7Example of Addressing a Range of PLC/PLC-2 Words#H024$015,4<<<Number of words to be trans

Addressing Rules and ExamplesChapter 4412Figure 4.8Example of Addressing Specific Bits in PLC/PLC-2 Memory#H015$0121/010<<<Bit number 10 (oc

Addressing Rules and ExamplesChapter 4413 1. A remote address can be used only with the single equals sign (=)type of assignment command. 2. In the

IntroductionChapter 113Table 1.BRelated Data Highway DocumentationPublicationNumber(Old/New No.)Title1770-810/1770-6.2.1Data Highway Cable Assembly a

Addressing Rules and ExamplesChapter 4414OperatorOrder ofExecutionOperation.LT.Compare less than8.LE.Compare less or equal8.NE.Compare not equal8.AND

Addressing Rules and ExamplesChapter 4415Number SystemsWithin an expression, direct values are always interpreted as decimal(base 10) numbers unless

Addressing Rules and ExamplesChapter 4416The result of a logical complement is 1 (true) if the expression followingthe .NOT. is a value of 0 (zero).

Addressing Rules and ExamplesChapter 4417The bitwise 32–bit EXCLUSIVE OR (.BXOR.) forms a bit–by–bit logicalEXCLUSIVE OR of two 32–bit operands. Ther

Addressing Rules and ExamplesChapter 4418If the accumulated value of counter 1 is greater than or equal to theaccumulated value of counter 2, then th

Chapter 551EditingThis chapter explains how to create and edit message procedures andcommands for the 1775–KA module. The message procedure commandst

EditingChapter 552Table 5.AExample of Message instruction EditingSystem PromptActionKey StrokesStart edits.SED [ENT]Insert rung.IR [ENT]Enter the ene

Chapter 553Table 5.BExample of Editing a Message Procedure Through an Industrial TerminalSystem PromptActionKey StrokesCreate the message procedure.

EditingChapter 554Note that it is not always necessary to create a message procedure. If youwant to execute just a single assignment command that is

Chapter 661Message Procedure CommandsThe 1775–KA module has its own command language that you can use inprogramming message procedures. This chapter

IntroductionChapter 114command is sometimes used synonymously to mean privilegedcommand. non–privileged commands include any command that both PC’s a

Message Procedure CommandsChapter 662Blanks may be inserted anywhere to improve the readability of a messageprocedure. However, blanks should be kept

Message Procedure CommandsChapter 663copies the value of user symbol US_5 into word 24 (octal) of input file12.ModifiersSeveral modifiers may be adde

Message Procedure CommandsChapter 664 Normal PriorityIf you use the less–than sign (<) with the assignment command, thecommand will generate a pri

Message Procedure CommandsChapter 665For example, the command#H027$0121=17407would generate a protected write command to write the value 1740–7 intow

Message Procedure CommandsChapter 666Using the DELETE command on a procedure name not only deletes thename but also erases the named procedure from P

Message Procedure CommandsChapter 667The format of the EXIT command is simply the single letterEWithout any modifiers or parameters.Each main procedu

Message Procedure CommandsChapter 668the value of the expression is false (0), the embedded command is notexecuted. The embedded command may be any o

Message Procedure CommandsChapter 669command line 1command line 2ON_ERROR GOTO RECOVERcommand line 3command line 4ON_ERROR ERR_CODE = $B2:16command l

Message Procedure CommandsChapter 6610There are two functions: TO_BCD FROM_BCDFigure 6.2 illustrates the format of these functions as they might appe

Message Procedure CommandsChapter 6611FROM_BCD FunctionThe FROM_BCD function converts its parameter frombinary–coded–decimal format to binary format.

IntroductionChapter 115Figure 1.1Communication Adapter Module (Cat. No. 1775-KA)10000-IPASSFAILSELFTESTKADATAHWYNOMODEMINTERFACEDATAHWYXMTGRCVGRDYERR

Chapter 771Error ReportingThe 1775–KA module detects and reports various types of errors.Appendix B lists all the errors reported by the module. As y

Error ReportingChapter 772To aid in error monitoring, the 1775–KA module maintains a 6–worderror block in the module status area of PLC–3 memory. Thi

Error ReportingChapter 773And word 3 gives the number of the line in procedure MAIN thatexecuted procedure SUB1.Figure 7.1Examples of Error Block Ope

Error ReportingChapter 774Note that an ON_ERROR or an IF command may contain an embeddedcommand to execute another procedure. In these cases, the em

Error ReportingChapter 775Access to Error BlockThe error block retains its data even after the message procedures aredone executing. It is re–initia

Chapter 881Programming ExamplesThis chapter presents some detailed examples of 1775–KA modulecommands and message procedures.The first set of example

Programming ExamplesChapter 882Figure 8.2Writing Data to a Remote PLC-3 Station10033-IData Type Assignment StatementFile #H045$N4 = $B3Destination fi

Programming ExamplesChapter 883Figure 8.3Writing Data to a Remote PLC/PLC-2 Station10034-IData Type Assignment StatementFile #H021$040 = $B3Destinati

Programming ExamplesChapter 884Figure 8.4 presents a printed listing of a Data Highway messageprocedure. As the listing indicates, the purpose of the

Programming ExamplesChapter 885Some of the statements in the sample procedure are not necessary toaccomplish the bit monitoring. However, they were i