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PACSystems RX3i Serial Communications Manual, GFK

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2. The module waits for the slave to return a copy of the query RX3i Serial Communications Module Port in MODBUS Slave Mode No exchange configuration is needed The Serial Communications module automatically responds with a copy of the master s query regardless of whether or not it is configured for Preconfigured Exchanges This command does not cause the module to exchange any data with the CPU GFK 2460A Chapter 5 MODBUS Communications 5 19 Write Multiple Coils Force Multiple Outputs MODBUS Function 15 The MODBUS Master can issue a Write Multiple Coils message to force up to 254 contiguous points in one slave s or all slaves discrete outputs coils Ox table The specified outputs are forced automatically Write Multiple Coils is not an output override command The outputs are guaranteed to be forced only once The query and normal response formats are Master Device Function Starting Number of Query Point Number Points Error Check 1 1 i 1 i Slave Device Function Starting Number of l Normal Address ak Point Error Check Response Point Number oints i RX3i Serial Communications Module Port in MODBUS Master Mode An RX3i Serial Communications module automatically forms a Write Multiple Coils query function code 15 from a Write exchange that has a Target Type of Coils 0x The module requests the content of the configured CPU reference address The values for the output points must be ordered by number starting w
3. 3 19 E Error Selector 4 12 Error Status Handling 4 14 F Faults Reported 1 2 Features 1 2 Flow Control 3 3 3 9 3 14 3 19 Flush Input Buffer 4 12 Flushing the Input Buffer 6 4 Index Force Single Coil 5 16 Four Wire MODBUS 2 9 G Grounding and Ground Loops 2 8 H Hardware Flow Control 6 3 Hazardous Locations 2 2 Infolink 1 1 Initializing Resetting the Port 6 3 Input Buffer 3 5 6 4 Input Data 4 5 6 5 Isolation 1 3 L LEDs 2 3 Loopback Maintenance 5 19 Machine Edition 1 2 Mask Write 4x Memory 5 23 Modbus reference tables 5 5 MODBUS Cable 2 7 MODBUS Communications Overview 5 2 MODBUS Functions 1 8 5 6 MODBUS Master Configuration 3 8 MODBUS Master Diagnostics 5 10 MODBUS Master Operation 5 8 MODBUS Message Formats 5 4 MODBUS Multidrop Connections 2 7 MODBUS Multidrop RS 485 1 5 MODBUS Slave Configuration 3 13 3 18 MODBUS Slave Operation 5 11 Modem 6 7 Module LEDs 2 3 N Normal Read Request from the CCM Master 7 6 Number of Modules 1 2 O Order Numbers 1 2 Index 1 Index Output Data 4 9 Outputs Disabled 4 2 P Parity 1 3 3 3 3 8 PLC Access 3 16 Point to Point Serial Connections 2 6 Port LEDs 2 3 Port Pin Assignments 2 4 Port Reset 4 11 Port Status 6 4 Port Status Input Data 4 3 Port Type 3 3 3 8 Preconfigured Exchanges 3 15 3 16 3 20 Preset Write Multiple Registers 5 21 Preset Write Single Regist
4. Read Continuous to read the data continually without having to set the exchange s Control Bit Read Continuous Bit Control to read the data continually after triggering the operation using the exchange s Control Bit Read Single Bit Control to read the diagnostic data each time the Control Bit is toggled Word Offset Description 1 Most recent internal error or MODBUS exception Hexadecimal error codes include 0000 No error 0001 Illegal function function code not supported by slave 0002 Illegal data address address is not available in slave or diagnostic code not supported 0003 Illegal value data format incorrect or data length specified is longer than data received 0004 Slave device failure query processing failure in the slave 0005 Acknowledge 0006 Slave device busy 0007 Negative acknowledge 0008 Memory Parity error 8xxx Internal errors 8001 Query timeout 8002 Response timeout 8003 UART response error 8004 Response length invalid 8005 Response CRC invalid 8006 Response slave ID invalid 8007 Response received after timeout Number of queries failed due to timeout Number of queries sent on the MODBUS port Number of normal responses received Number of exception responses received Number of responses failed due to timeout Number of responses failed due to U
5. The sum of the starting point number value and the number of points value must be less than or equal to the highest output point number in the slave When all the data has been received from the MODBUS Slave the module automatically writes the data highlighted above from the configured CPU Reference Address area and updates the exchange status information RX3i Serial Communications Module Port in MODBUS Slave Mode Using the default Data Exchanges the module automatically requests from the CPU an area of the l reference table The starting reference address and length are specified in the master s query f a new exchange is configured the PLC Access mode may be either Read Only or Read Write The Target Type must be Discrete In 1x The Target Address is the offset from the start of the Master s Discrete Inputs table The configured Reference Address and Reference Length specify the CPU location of the data available to be read The module receives the requested data from the CPU then immediately sends it to the MODBUS Master using a Normal Response as shown above GFK 2460A Chapter 5 MODBUS Communications 5 13 Read Holding Registers Read Registers MODBUS Function 03 The master can directa MODBUS Read Holding Registers message to a specified slave to read up to 254 bytes 127 registers from the slave s registers holding registers 4x table The query and normal response formats are Device Function
6. These values are in addition to the character that is being transmitted at the time CTS is de asserted Outputs Disabled Control Default is Stop Processing Exchanges Alternative is Continue Processing Exchanges This option applies to continuous read and write exchanges It does not apply to bit controlled continuous exchanges or to single exchanges Port Config ID Setting User Config ID Default is 1 range is 0 to 255 GFK 2460A Chapter 3 Configuration 3 9 Configuring MODBUS Master Exchanges If the protocol selected for a port is MODBUS Master configure up to 64 data exchanges on the corresponding PortData_Modbus Master tab Based on the selections made on this screen the Serial Communications module will execute the appropriate standard MODBUS functions Settings Port1 Port 2 Port3 Port 4 PortData ModbusMaster 1 PortData_ModbusMaster 2 PortData_ModbusMaster 4 Power Consumption Ref Address Ref Length Read Continuous oils Ox 1 j Data Exchange Number 2 Data Exchange Number 4 Data Exchange Number 6 Data Exchange Number 8 at Data Exchange Number 9 i Data Exchange Number 10 Disabled When configuring master exchanges remember that read exchanges will read data from the slave target and write it to the specified reference address Write exchanges will read data from the specified reference address and write it to the slave target Looking at the fields on the exchange configuratio
7. half duplex operation for RS 485 422 Flow Control for R 232 Selectable Hardware CTS RTS or none Turnaround Delay 6mS minimum enforced by module External devices must hold off response for at least 6ms after the last character received Baud rates 1200 2400 4800 9600 19 2K 38 4K 57 6K 115 2K Parity Even odd none Data bits 7 8 Stop bits 1 2 Operating Temperature 0 C to 60 C Input Impedance Zin gt 96 kOhm for RS 485 422 3 kOhm lt Zin lt 7 kOhm for RS 232 Max Overvoltage 25V Channel Channel Crosstalk 55 dB minimum Isolation Port to Backplane and to frame ground 250 VAC continuous 1500 VAC for 1 minute 2550VDC for one second Port to port 500VDC continuous 710VDC for one minute In order to meet emission and immunity requirements for the EMC directive CE mark shielded cable must be used with this module GFK 2460A Chapter 1 Introduction 1 3 Communications Standards Each port on an RX3i Serial Communications module supports the RS 232 RS 422 and RS 485 standards for asynchronous serial communications RS 485 has largely replaced RS 422 because it guarantees multidrop capability RS 232 In RS 232 mode a port transmits and receives data and control signals on unbalanced circuits with one Signal Common or Signal Ground wire serving as the return path for all the data and control circuits RS 232 is suitable fo
8. restarts operation as though the port just received another configuration All port operations and data are initialized and reset according to the configuration The port will only be reset GFK 2460A Chapter 4 Port Status and Control Data 4 11 again if the module sees a transition from the Port Reset bit from a 0 to a 1 The port remains in Reset if the CPU is not in Run mode Port Exchange Error Selector Output Bits 73 80 The value in byte 10 output bits 73 80 of the port Output Data is the Port Exchange Error Selector Initially there are no errors for any exchange on a port so this value can be set to 0 As long as the Error Exchange Number Selector value is 0 the Error Status input bits 201 208 and Error Status Exchange Number input bits 193 200 fields contain the last processed exchange error status and the exchange number respectively If the number of a specific exchange is entered in this byte the module will return its error status in the Port Status input data Output Commands to the Module Output Bits 81 128 For Serial I O The CPU can use output bytes 11 16 bits 81 128 for each port to control Serial I O Protocol operations Cancel Pending Receive Operation Output Bit 81 Setting this bit to 1 stops a pending Serial I O receive If this bit is set when a Receive is ongoing the Receive stops and the error code is changed to 24 The data is not flushed from the buffer when this occurs Subsequent Recei
9. s reference table definition is different from the internal structure of the PACSystems reference tables MODBUS terminology refers to Holding Register Input Register Input Discrete and Coil tables PACSystems terminology refers to Discrete Input l Discrete Output Q Analog Input AI Register R and Word W reference tables The following table compares MODBUS data types and lengths with equivalent PACSystems reference tables PACSystems MODBUS Holding MODBUS Input MODBUS Input MODBUS Coil Reference Tables Register Table Register Table Discrete Table Table 4xxxx 3xxxx 1xxxx 0xxxx 11 32768 1 32768 bits bits AI1 32640 16 bit words Q1 32768 1 32768 bits bits R1 32640 1 32640 16 bit words 16 bit words GFK 2460A Chapter 5 MODBUS Communications 5 5 MODBUS Communications for RX3i Serial Communications Modules PACSystems RX3i Serial Communications modules IC695CMM002 and IC695CMM004 use the standard MODBUS Function codes listed below to communicate with MODBUS devices Supported MODBUS Functions Function Function MODBUS MODBUS Code Master Slave 01 Read Coil Status Read Output Table Yes Yes 02 Read Input Status Read Input Table Yes Yes 03 Read Holding Registers Yes Yes 04 Read Input Registers Read Registers Yes Yes 05 Force Single Coil Force Single Output Yes Yes 06 Preset Write Single Register Yes Yes
10. the module will return all data from the serial channel up to the specified number of bytes If the length is set to 0 all bytes in the port s input buffer will be received The word of data between bits 177 192 of the port s input status data indicates the number of bytes read If there are no characters in the port s input buffer the module terminates the receive operation immediately The module sets the port s Exchange Error Report bit to 1 and the received character count to 0 Read Dynamic Byte Count If the ports Read Control Operation is configured for Dynamic Read Length the application sends the number of bytes to be read in the word between bits 97 112 of the Port Control Data The module then reads the data as described above for Read Fixed Byte Count 3 The module immediately sends the serial data to the CPU 4 The module updates the port s error status received character count and input buffer characters available information in the Port Status data and sets input bit 1 to match the state of output bit 1 When these two bits match it indicates that the Serial I O read has been completed GFK 2460A Chapter 6 Serial I O Communications 6 5 sl Writing Serial I O Data The CPU references to be used for serial data and the length of data that will be written in each transmission are set up in the port configuration The application logic controls transmission of serial data using the port s status an
11. 193 200 Byte 25 For MODBUS Master or Slave When an error occurs on a port this byte identifies the exchange number that had the error If the Error Exchange Number Selector output bits 73 80 is 0 this byte contains the last processed exchange number whether or not that exchange had an error To retrieve the error status of a specific exchange the CPU must send the module its exchange number in the Port Control output data For Serial I O A value of 1 in this byte indicates a receive error and a value of 2 indicates a transmit error GFK 2460A Chapter 4 Port Status and Control Data 4 7 Error Status Input Bits 201 208 Byte 26 When an error occurs on a port this byte contains a number representing the error type for example 2 receive overflow See the previous table for a list of error numbers If the Error Exchange Number Selector output bits 73 80 is 0 this byte contains the error status of the last processed exchange whether or not that exchange had an error To retrieve the error status of a specific exchange the CPU must send the module its exchange number in the Port Control output data Period Time Input Bits 209 224 Bytes 27 28 For MODBUS Master these two bytes contain the time required to execute all master exchanges in milliseconds Each time all exchanges have been scanned either processed or passed over this value is updated indicating the time it took for the Exchange scan to complete
12. CCM slave will immediately end a transaction if a data block is not valid Turn Around Delay Default is 0 Range is 0 to 65535mS This is a time to be added to the CCM protocol s base timeout period Setting Turn Around Delay to 0 does NOT disable timeouts For CCM there are eight predefined timeouts see chapter 7 conditions The overall timeout period is the sum of these eight timeouts plus the Turn Around Delay configured here plus the configured Timeout in milliseconds GFK 2460A Chapter 3 Configuration 3 19 Setting Up CCM Slave Data Exchanges Data Exchanges set up specific communications between a Serial Communications Module and its local RX3i PLC CPU over the RX3i backplane CMM CCM Master Module CCM Communications When a port is set up for CCM Slave operation a set of default Data Exchanges is provided for that port that will permit the CCM Master to read or write all locations in R l and Q memory and to set and clear all bits l and Q memory in the PACSystems CPU The default Data Exchanges are shown below These Data Exchanges match any CCM request the module might receive from the CCM Master The Ref Length of 0 means there is no length restriction the entire CPU table Reference Address type in that Data Exchange is accessible RX3i CPU CCM RX3i CPU Access Addressing Addressing SSS eae Settings Pott1 Pot2 PortData_CCM_Slave 1 Power Consumption Data Exchange Number 1 Data Exchange N
13. Exchange Error Report bit in the Port Status input data to 1 When an error bit is set it remains set until the application has acknowledged the error cleared all errors reset the port downloaded a new configuration For a Read Single or Write Single Bit controlled exchange the Exchange Error Report bit will automatically be cleared if the next exchange has no errors Acknowledging Errors To acknowledge one error specify the error number in the Port Exchange Error Selector output bits 73 80 and set the Acknowledge Current Error bit output bit 65 to 1 Multiple exchange errors can be acknowledged by sending the module a sequence of commands updating the Port Exchange Error Selector value without toggling the Acknowledge Current Error for each acknowledgement The module responds by mirroring the Port Exchange Error Selector value in the port s Error Status Exchange Number field input bits 193 200 and by setting the Error Status field input bits 201 208 to 0 Clearing All Errors on a Port All exchange errors are acknowledged and reset to 0 by setting the Clear All Errors bit setting the Port Reset bit or downloading a new configuration 4 14 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Using DO I O and Suspend I O Both the DO I O and Suspend I O program functions can be used with PACSystems RX3i Serial Communications modules Suspend I O suspends I O updates for the module DO I
14. For MODBUS Slave and Serial I O these bytes are reserved 4 8 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Port Control Output Data The Port Control output data for each port is shown below The byte and bit values used in the table represent relative offsets from the start of each port s control data Byte Bit Description 1 8 1 64 Exchange Control Bits MODBUS Master One bit per exchange Used if the Operation type is one of the Bit Control choices such as Read Single Bit Control Serial I O Bit 1 Receive Setting this bit to a different value than the corresponding Port Status bit enables the module to receive a new packet if one exists Bit 2 Transmit Setting this bit to a different value than the corresponding Port Status bit commands the module to initiate the next packet transmission CCM Slave One bit per exchange Used if the PLC Access type is one of the Bit Control choices such as Read Single Bit Control One bit per exchange Not used for other PLC Access types 9 65 72 Port Command Bit 65 1 Acknowledge the error indicated in the Error Status and Error Status Exchange Number input data fields Bit 66 1 Clear All Errors Bit 67 1 Port Reset Bits 68 72 spare 10 73 80 Port Exchange Error Selector byte Specifies the Exchange Number for which the Error Status and Error Status Exchange Number will be retu
15. Introduction to MODBUS Communications Each port on an RX3i Serial Communications module can be set up for either MODBUS Master or MODBUS Slave operation RX3i Serial Communications modules handle MODBUS master or slave communications without the need for COMMREQ commands in the application program Chapter 5 MODBUS Communications explains how RX3i Serial Communications modules handle each supported MODBUS function in master or slave mode The following MODBUS functions are supported Supported MODBUS Functions Function Function MODBUS MODBUS Code Master Slave 01 Read Coil Status Read Output Table Yes Yes 02 Read Input Status Read Input Table Yes Yes 03 Read Holding Registers Yes Yes 04 Read Input Registers Read Registers Yes Yes 05 Force Single Coil Force Single Output Yes Yes 06 Preset Write Single Register Yes Yes 07 Read Exception Status No Yes 08 Diagnostics Loopback Maintenance Yes Yes Diagnostic Code 00 Return Query Data Reads query data Yes Yes from one slave 15 Write Multiple Coils Force Multiple Outputs Yes Yes 16 Preset Write Multiple Registers Presets a group of contiguous Yes Yes registers to a specified value 17 Report Slave ID Report Device Type No Yes 20 Mask 4x Registers No Yes 23 Read Write 4x Registers No Yes Supported Transmission Mode RX3i Serial Communications modules execute MODBUS communications in RTU Remote Terminal Unit tra
16. MODBUS 0 no error detected Master or 1 error detected This bit remains 1 until errors are acknowledged Slave One bit per exchange bit 65 exchange 1 to bit 128 exchange 64 Bit 65 1 indicates a receive error has occurred Serial I O Bit 66 1 indicates a transmit error has occurred Bits 67 128 Reserved 0 no error detected CCM Slave 1 error detected This bit remains 1 until errors are acknowledged One bit per exchange bit 65 exchange 1 to bit 128 exchange 64 17 129 Port Status 18 144 Bit 129 Port Ready 1 Bit 130 Configuration underway 1 Bit 131 1 Control Bit Ready The Exchange Control bit is being used for bit controlled operations Set to 0 if outputs are disabled 132 136 Reserved 137 144 Byte 18 Configuration ID from the Port configuration tab 19 145 MODBUS Master Slave this data not used GFK 2460A Chapter 4 Port Status and Control Data 4 3 Bytes Bits Description 24 192 Serial I O Protocol Status Bit 145 CTS Status for RS232 when HW Control Disabled 0 Not CTS 1 CTS Bits 146 160 Spare Bits 161 176 Word Number of input buffer characters bytes available Bits 177 192 Word Number of characters bytes received CCM Slave Not used 25 193 Error Status Exchange Number 200 MODBUS Master Slave Exchange number of the error in the Error Status field below Serial I O Value of 1 receive error 2 t
17. PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A L Reading Input Data The application logic in the RX3i CPU is responsible for reading data from the input buffer into its assigned CPU reference area 1 To read Serial I O data from the RX3i Serial Communications module s input buffer the application program toggles bit 1 of the Port s Control output data to the opposite state 2 The module reads the requested data from its internal buffer The amount of data transferred depends on the parameters that were chosen for the Serial I O Read configuration Read Input Buffer Only f the Read Control Operation configuration parameter is set to Receiving Disabled the receive transaction will only read data bytes that are already in the port s input buffer The number of bytes actually read is indicated in the word of data between bits 177 192 of the port s input status data Read a Data String f the Read Control Operation parameter is configured for Read Delimiter the module reads data until the specified termination sequence occurs or until an error is detected If a Timeout value has been configured and a timeout occurs before the termination sequence is received any data collected before the timeout is discarded If the terminating character cannot be found the receive operation terminates immediately Read Fixed Byte Count If the port s Read Control Operation is configured for Byte Count
18. be used as is or customized for the application For other protocols such as MODBUS master the configuration of a port includes defining all of the data exchanges that will be read or written by the port Up to 64 exchanges can be defined Settings Port 1 Port 2 PortData_ModbusMaster 2 PortData_ModbusSlave 1 Power Consumption Data Exchange Number Slave Address Target Address Ref Address Ref Length Data Exchange Number 1 R Data Exchange Number 2 D Data Exchange Number 3 D Data Exchange Number 4 Data Exchange Number 5 D 1 6 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Introduction to Serial Communications Module Data During system operation an RX3i Serial Communications module exchanges two basic types of data with the system CPU Status and Control data and Serial Communications data Data formats are detailed in chapter 4 Port Status and Control Data Status and Control Data The module exchanges status input and control output data for each port with the CPU during the CPU s I O Scan Transfer of this data is controlled by the CPU Status and control data for each port uses reference addresses that are assigned during module configuration Settings Port 1 Port 2 PortData_SeriallO 1 Power Consumption Parameters 0 Settings ort 1 Status Data Port 1 Status Data Length ala ol Be o 2 o a o Port 1 Contr
19. buffer If the buffer becomes full any additional data received from the serial port is lost The application logic can monitor port status to see how much space is used in the input buffer The application logic is responsible for reading data out of the buffer in a timely manner so that incoming data will not be lost The application can also flush the input buffer which removes input data that has not yet been read Reading the Port Status Each CPU sweep the module automatically informs the CPU of the status of the Serial I O input buffer in the Port Status input data The application logic should monitor this status to be sure input data is not lost Port input bits 161 176 word data contain the number of input buffer characters that have been received Port input bits 177 192 word data contain the number of input buffer characters that were last transferred from the input buffet to PLC memory This makes it possible to determine how many bytes of the last received data are new Flushing the Input Buffer The port s Serial I O input buffer can be cleared by setting bit 83 flush input buffer in the Port Control output data to 1 This operation empties the input buffer of any characters received through the serial port but not yet read by the CPU If the application tries to flush the buffer while a read operation is pending the read buffer operation is executed first then the buffer is cleared of all remaining data 6 4
20. bytes have been read the read operation stops The entire contents of the ports 2K bytes input buffer The port can be configured to write A predetermined length of data When the specified number of bytes have been written the write operation stops A changeable length of data with the length supplied by the application in the port s output data When the specified number of bytes have been written the write operation stops Monitoring and Controlling Serial I O Communications Instead of using COMMREQ commands in the application program RX3i Serial Communications modules use the port s status and control data to monitor and control serial communications Chapter 4 Status and Control Data describes all of the input and output data that is automatically exchanged between the CPU and a Serial Communications module The application uses this data to start and stop communications to monitor communications status to clear errors to reset the port and to implement hardware flow control GFK 2460A Chapter 1 Introduction 1 9 Introduction to CCM Slave Communications Each port on an RX3i Serial Communications module revision 1 10 or later and Proficy Machine Edition 5 6 SIM 6 or later can be set up for CCM Slave protocol CCM Slave protocol makes RX3i CPU data accessible to a variety of GE Fanuc devices such as Series 90 30 and Series 90 30 CCM and PCM modules RX3i Serial Communications modules do not support CCM Mas
21. first byte The Slave ACKnowledges the Enquiry it sends a NAK if it is busy The Master then sends the slave a 17 byte Header that specifies the type of communication being requested read target memory address data length x x E g gt g i Ne NM E After receiving a data read request the Serial Communications module requests the data from the RX3i CPU The CPU transfers all of the requested data to the module in a single backplane write The transfer is generally completed within 4 16mS However if the module is running processor intensive protocols on the other ports it may take longer Qa lS Master QZ Glin 79 Slave Full Data ETB Slave ID STX Block ETB The Serial Communications Module Slave starts returning the data to the Master immediately after Acknowledging the Header If the Master has requested more than 256 bytes of data the data is returned in multiple blocks each with the format shown above All blocks except the last have 256 data bytes The Master returns an ACK response after receiving each data block After the Master acknowledges the last data block the Slave returns an End of Transmission character to the Master The Master responds with an End of Transmission character ending the communication Quick Read Request from the CCM Master The Master can use a Quick Read request to read bytes 11 through 14 of the Port Control Output Data directly from the module The applicatio
22. for RS 485 Full Duplex 4 Wire RS 485 3 Terminating Resistor Half Duplex 2 Wire RS 485 1 Terminating Resistor Built in Termination for RS 485 By default each port is set for no termination To set 120 Ohm termination internally 1 Remove the module s faceplate by pressing in on the side tabs and pulling the faceplate away from the module 2 With the module oriented as shown move either the upper or lower jumper Internal 120 Ohm Termination Default Jumper Positions Jumper for Full Duplex 4 Wire in Default Upper Position Jumper for Half Duplex 2 Wire in Default Upper Position Front of Module with Faceplate Removed 77 Full Duplex Four Wire RS 485 Move top jumper down or connect Port pins 7 and 3 Leave bottom jumper in Default Position a Leave top Jumper in Half Duplex Two Wire RS 485 Default Position Move bottom jumper down or connect Port pins 4 and 1 GFK 2460A Chapter 2 Installation and Wiring Point to Point Serial Connections When the network has only one slave device a point to point connection between the master and slave is used The cable connection may be either RS 232 or RS 485 RS 232 MODBUS RS 232 MODBUS should only be used for shorter distances typically less than 20 meters MODBUS Devices that use an RS 232 interface define the following connections
23. however only inputs from the specified reference table are copied T00200 T00201 ot S I100001 I00032 E The example DO I O function block above will update both the bit and word data for a module with a l starting reference of l00001 When the DO I O function receives power flow and output references are specified the output points starting at the reference ST and ending at END are written to the referenced module s GFK 2460A Chapter 4 Port Status and Control Data 4 15 If outputs should be written to the output modules from internal memory other than Q or AQ the beginning reference can be specified using the ALT input If a discrete Q reference is specified with no alternate source both the control Q and command AQ data are updated using the module s Q and AQ data The example DO IO function block below will transfer 32 bits of discrete data from the alternate source location starting at T1 to the module configured with Q starting reference of Q00001 T00201 S If previous outputs have not been consumed because DO I O has been attempted within less than one module sweep since outputs were last written then DO I O terminates and does not pass power flow 4 16 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Chapter MODBUS Communications 5 MODBUS communications are set up primarily within the module s configuration as described in chap
24. of zero data bytes An external device attempted to transfer data to or from an invalid memory type or absolute source address An external device attempted to read or write one or more a non existent Diagnostic Status Words 12 Serial communication was aborted after a data block was retried three times or more times than permitted 20 One or more of the following errors occurred during a data block transfer An invalid STX Start of Text character was received An invalid ETB End of Block character was received An invalid ETX End of Text character was received An invalid LRC Longitudinal Redundancy Check character was received A parity framing or overrun error occurred An EOT End of Transmission character was expected and not received 22 An ACK Acknowledge or NAK Negative Acknowledge character was expected and not received 26 A timeout occurred during an attempt to transmit on a port due to CTS being in an inactive state too long 29 An error occurred when data was being transferred between the Module and Backplane Mail system error A parity framing or overrun error occurred during a Header transfer A parity framing or overrun error occurred during a data block transfer Transmission Errors CCM uses parity checking and LRC longitudinal redundancy checking Parity checking is used to detect errors within a character It can be configured as even odd or none The parity bit is derived by the sender and
25. parity ODD or EVEN the character length used by MODBUS Master is 11 bits one start bit 8 data bits one parity bit and one stop bit When None is selected 2 stop bits are required Stop Bits Default is 1 Choices 1 2 If Parity is set to Odd Even the number of Stop Bits should be 1 If Parity is set to None the number of Stop Bits should be set to 2 The Stop Bits setting should be 1 stop bit for compatibility with other GE Fanuc Automation MODBUS Slaves Timeout mS Default is 100ms Range is 0 to 65535ms A 500 milliseconds timeout is recommended by the MODBUS standard The time out begins after the port has transmitted the last character of the query and stops when the character gap timeout expires after the last response character is received If the response timeout expires before the end of the character gap time out the port is checked for a response message If one is detected for example because the response timeout expired after the response was received but before the gap timeout expired the response is processed normally after the gap timeout expires If no valid response is detected a timeout error code is returned to the status location GFK 2460A Chapter 3 Configuration 3 13 Port Type RS232 RS485 2 wire or RS485 4 wire Tx RTS Drop Delay bits defaults to 0 Range 0 to 15 bits For RS232 or RS485 4 wire This is the time from the end of the last transmitted character to the time when RTS is turned off
26. registers of data to a slave s Registers 4x table Report Slave ID 17 Not available in Master mode Mask 4x Registers 22 Not available in Master mode Read Write 4x Registers 23 Not available in Master mode Handled automatically by default GFK 2460A Chapter 5 MODBUS Communications 5 7 MODBUS Master Operation for RX3i Serial Communications Modules When a port is configured for MODBUS Master operation the module acts on behalf of the CPU to exchange data with MODBUS Slaves on the network Because the RX3i Serial Communications modules handle the details of MODBUS communications automatically it is only necessary to set up MODBUS device addresses exchange types and memory addresses in the hardware configuration The application program only needs to handle any data that is sent to MODBUS devices or received from them and the sending and receiving of MODBUS data that is controlled by the exchange control bits The module automatically forms a complete MODBUS message around the data to be read or written For both Master and Slave protocols the Exchange information includes an address to reference memory locations with the RX3i CPU and an address to MODBUS memory locations with the externally connected Slave Both addresses are selected in the Machine Edition configuration The maximum data length that can be exchanged between the master and the slave is 254 bytes The length is configu
27. specifications 1 3 W Write Continuous 3 11 Write Control Operation 3 7 Write Data Length 3 7 Write Length 4 12 Write Multiple Coils 5 20 Write Periodic Bit Control 4 10 Write Single Bit Control 3 11 4 11 Writing Serial I O Data 6 6 Index 2 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A
28. stops processing on that port and restarts operation as though the port just received another configuration Resetting the port initializes all port operations according to the port s configuration To reset a port the application logic sets bit 67 Port Reset in the port s Port Control Data to 1 The port will only be reset again if the module sees another scan of the Port Reset bit still set to 1 The port remains in Reset if the CPU is not in Run mode The port will reset again every time this bit is not set back to 0 for an output scan Managing Hardware Flow Control for RS 232 Communications For RS 232 communication if the port s Flow Control parameter has been configured for Hardware Flow Control RTS CTS the application should set output bit 84 Activate RTS in the port s Port Control Data to 1 to force RTS on the port before transmitting The application should then check input bit 145 CTS active When this bit is 1 the port can safely transmit If CTS does not become active within 2 seconds the module returns a timeout error to the status location If CTS becomes active and then de asserts additional data transmission must stop until CTS reasserts After the last transmit character is sent the application must set the RTS bit to 0 GFK 2460A Chapter 6 Serial I O Communications 6 3 sl Reading Serial I O Data When the module receives Serial I O input data it automatically stores the data in the 2048 byte input
29. t 3 Master staring Number of Error Check Query Register No Registers Slave Device Function l Normal Address Error Check Response RX3i Serial Communications Module Port in MODBUS Master Mode An RX3i Serial Communications Module automatically forms a Read Holding Registers query function code 03 from a Read exchange that has a Target Type of Holding Registers 4x The module directs the query to the device address configured Station Address of the slave The starting register configured Target Address can be any value less than the highest holding register number available in the slave The number of registers configured exchange Reference Length specifies the number of registers requested The sum of the starting register number value and the number of registers value must be less than or equal to the highest register number in the slave When all the data has been received from the MODBUS Slave the module automatically writes the data highlighted above to the configured CPU Reference Address area and updates the exchange status information RX3i Serial Communications Module Port in MODBUS Slave Mode Using the default Data Exchanges the module automatically requests from the CPU an area of the R reference table The starting reference address and length are specified in the master s query If a new exchange is configured the PLC Access mode may be either Read Only or Read Write The Target Type must be Ho
30. time when RTS is turned off Flow Control for RS232 only Default is none Choices are None or Hardware Control RTS CTS If Hardware Control is specified the port will assert RTS then wait for CTS to become active before transmitting If CTS does not become active before the timeout period expires an error code 0x1A is set in the Diagnostic Status data If the exchange number is known when the error occurs error code 0x1A is also set in the Exchange Error location If CTS becomes active and then is de asserted while the port is transmitting up to 5 milliseconds may elapse before transmission stops The maximum number of characters transmitted after CTS is de asserted is proportional to the data rate These values are in addition to the character that is being transmitted at the time CTS is de asserted Outputs Disabled Control Default is Stop Processing Exchanges Alternative is Continue Processing Exchanges CCM Slave Port Settings Station Address The CCM Slave ID used for the port Default is 1 Range is 1 to 90 Header Retries Number of times the CCM Slave will allow the Master to resend a header before sending EOT Default is 3 Range is 0 to 5 If Header Retries is set to 0 the CCM slave will immediately end a transaction if a header is not valid Data Block Retries Number of times the Slave will allow the Master to resend a data block before sending EOT Default is 3 range is 0 to 5 If Data Block Retries is set to 0 the
31. to 0 or vice versa Bit 2 Transmit Packet If the state of the second bit in the Port s Status input data is the same as the current state of the second output bit Transmit Packet it means that the previous Serial I O transmission has completed The CPU can begin a new transmission by setting this bit to its opposite state if the Transmit Packet output bit is 1 set it to 0 or vice versa Port Command Output Bits 65 72 Byte 9 The CPU can set individual the Port Command output bits to acknowledge or clear errors or reset the port Acknowledge Current Error Output Bit 65 The CPU can set this bit to 1 to acknowledge the error that is currently indicated by the Error Status and Error Status Exchange Number input data fields The module responds by mirroring the Port Exchange Error Selector value in the port s Error Status Exchange Number field input bits 193 200 and by setting the Error Status field input bits 201 208 to 0 The CPU can acknowledge multiple exchange errors by sending the module a sequence of commands and updating the Port Exchange Error Selector value output bits 73 80 without toggling the Acknowledge Current Error bit output bit 65 from 1 to 0 to 1 for each acknowledgement Clear All Errors Output Bit 66 The CPU can set output bit 66 to 1 to acknowledge all exchange errors and reset their error status to 0 Port Reset Output Bit 67 Setting the Port Reset bit to 1 stops processing on that port and
32. will be reported to the status location if this timeout expires before a complete response is received MODBUS requires a timeout in all cases A 500 milliseconds timeout is recommended by the MODBUS standard If no valid response from the slave is detected after the configured timeout period an error code is returned to the status location Port Type RS232 RS485 2 wire RS485 4 wire Tx RTS Drop Delay bit times defaults to 0 Range 0 to 15 bit times This is the time from the end of the last transmitted character to the time when RTS is turned off dropped 3 8 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A The receiver is disabled during transmission and remains disabled during the RTS drop delay time If the specified delay is longer than the MODBUS Slave s silent interval between the query and its response the master will ignore all or part of the response Flow Control for RS232 only Default is none Choices are None Hardware Control RTS CTS If Hardware Control is specified the port will assert RTS then wait for CTS to become active before transmitting If CTS does not become active within 2 seconds a time out error code is returned to the status location If CTS becomes active and then is de asserted while the port is transmitting up to 5 milliseconds may elapse before transmission stops The maximum number of characters transmitted after CTS is de asserted is proportional to the data rate
33. 07 Read Exception Status No Yes 08 Diagnostics Loopback Maintenance Yes Yes Diagnostic Code 00 Return Query Data Reads query data Yes Yes from one slave 15 Write Multiple Coils Force Multiple Outputs Yes Yes 16 Preset Write Multiple Registers Presets a group of contiguous Yes Yes registers to a specified value 17 Report Slave ID Report Device Type No Yes 20 Mask 4x Registers No Yes 23 Read Write 4x Registers No Yes Supported Transmission Mode RX3i Serial Communications modules execute MODBUS communications in RTU Remote Terminal Unit transmission mode The entire message is transmitted as a continuous stream of characters Between characters the line is held in the 1 state In RTU transmission mode gaps of silence are used to frame a message Because message frames must be separated by intervals of silence MODBUS RTU is not recommended for use with modems which can compress or change the gaps between frames and interfere with message timing 5 6 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A How MODBUS Functions are Implemented PACSystems RX3i Serial Communications modules handle MODBUS Master and Slave communications without the need for COMMREQ commands in the application program For reference the table below lists in the left column MODBUS functions that are done using COMMREQs for RX3i CPUs For RX3i Serial Communications modules in MODBUS Master mode the same functions are han
34. 1 for 1 03 4 Backplane Run Status 5 Minor Revision Code eg 03 for 1 03 6 0 reserved 7 0 reserved 8 OxXX CRC error check 9 OxXX CRC error check 5 22 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Mask Write 4x Memory Register Table MODBUS Function 22 The master can issue MODBUS message Mask Write 4x Memory function code 22 to modify the content of a specified register in slave Register Holding Registers 4x memory The query and response formats are Master Device Function Register Query Number Slave Device Function Register Normal Address Number Response Error Check Error Check RX3i Serial Communications Module Port in MODBUS Master Mode This function is not supported by an RX3i Serial Communications module port configured for MODBUS Master mode RX3i Serial Communications Module Port in MODBUS Slave Mode Using the default Data Exchanges the module automatically requests from the CPU an area of the R reference table The starting reference address and length are specified in the master s query If anew exchange is configured the PLC Access mode must be Read Write The Target Type must be Holding Regs 4x The Target Address is the offset from the start of the Master s Holding Registers table The configured Reference Address and Reference Length specify the CPU location of the data available to be written When the module receives
35. 16 bit words registers The default is 0 which means there is no restriction and the entire table starting at the Reference Address offset is available for access by the CCM Master For example here Data Exchange Number 5 has been edited so that the master can set only 16 bits beginning at 100049 in the Input Table Data Exchange Number 3 Data Exchange Number 4 fre EZ 4 at 4 More exchanges can be defined to allow the Master access to additional ranges within a memory type For example here Data Exchange Number 8 will allow the Master to set input bits from 100257 to the end of the Input Table In this example Input table bit 1 is written to 100257 Input table bit 2 is written to 100258 Input table bit 400 is written to 100656 Data Exchange Number 7 rite Uniy Output Table Bit CWT Data Exchange Number 8 Write On ie Sie Sia I Access to other memory types can be provided by either editing the default exchanges or defining additional exchanges For example here Data Exchange Number 9 will allow the Master to Read Write the RX3i Analog Input Table Data Exchange Number 8 Data Exchange Number 9 Write On Re ut Table Bit Data Exchange Number 9 includes both bit type and word type memories For this exchange the slave has 64 x 16 1024 bits of Input Table data mapped to the first 64 words of AI memory for the Master to access GFK 2460A Chapter 3 Configurati
36. 32 RS 485 422 communication software selected Hardware handshake RTS CTS for RS 232 Selectable Baud Rates 1200 2400 4800 9600 19 2K 38 4K 57 6K 115 2K Module fault status reporting Watchdog Ram Fail Flash Fail Module identity and status reporting including LED status indicators Meets CE UL CUL 508 and 1604 and ATEX requirements Flash memory for future upgrades These modules must be located in an RX3i Universal Backplane An RX3i CPU with firmware version 3 83 or later is required Machine Edition 5 5 with Service Pack 2 SIM 4 or later is required for configuration Machine Edition 5 6 SIM 6 or later is required for CCM Slave protocol RX3i Serial Communications Modules can be hot inserted and removed following the instructions in the PACSystems RX3i System Manual GFK 2314 1 2 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Module Specifications Number of Serial Ports IC695CMMO02 two independent serial ports IC695CMMO004 four independent serial ports Connectors RJ 45 Number of Serial Communications Modules per CPU Six in the main CPU backplane Backplane power requirements IC695CMMO002_ 0 7 Amps maximum 3 3 VDC 0 115 Amps maximum 5 0 VDC IC695CMM004 0 7 Amps maximum 3 3 VDC 0 150 Amps maximum 5 0 VDC LEDs Module OK Port Fault Port Status 2 or 4 Port Type RS 232 or RS 485 22 4 wire full duplex or 2 wire
37. 41h A 41h T 54h 5444h D 44h T 54h 3332h Phone number 2 32h 3 33h 3534h 4 34h 5 35h 3736h 6 36h 7 37h 0D38h 8 38h lt CR gt 0Dh GFK 2460A Chapter 6 Serial I O Communications 6 7 6 8 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Chapter CCM Communications Built in CCM slave protocol allows a PACSystems RX3i Serial Communications module revision 1 10 or later to communicate with a variety of GE Fanuc devices Communications characteristics are set up primarily within the module s configuration as described in chapter 3 Configuration Chapter 4 Port Status and Control Data details the data that is automatically exchanged between the module and the RX3i CPU each I O Scan The application uses that automatic data transfer to control and monitor communications through each port This chapter describes CCM Slave operations for RX3i Serial Communications modules CCM Overview CCM Commands Supported by RX3i Serial Communications Modules CCM Slave Operations for the Serial Communications Module Write Request from the CCM Master Normal Read Request from the CCM Master Quick Read Request from the CCM Master Scratchpad Data Diagnostics Data for CCM Slave Ports GFK 2460A 7 1 CCM Overview CCM protocol is a serial communications protocol used by GE Fanuc Programmable Logic Controllers PLCs to share data between PLCs or between PLCs and a host comp
38. 512 bits variables During system operation Port Status and Port Control data is transferred between the RX3i CPU and a Serial Communications module during the CPU s I O Scan Serial Communications Module MODULE OK PORT FAULT P1 P2 P3 P4 CPU Sweep Read Inputs Port Status Data Execute Application Program Write Outputs Port Control Data IC695CMM004 If the CPU is stopped with outputs disabled it stops exchanging Port Status and Control data with the module When the CPU goes back into Run mode it resumes reading Port Status data and module status information The application should monitor the Port Status input data for information about serial communications status and use the Port Control output data to send the module commands acknowledge faults or reset a port In addition to being transferred during the I O Scan transfer of status and control data can be controlled using the DO I O and Suspend I O program functions as described in this chapter 4 2 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Port Status Input Data The Port Status input data format for each port is shown below The byte and bit values used in the table represent relative offsets from the start of each port s status data Bytes Bits Description 1 8 1 64 Exchange Response Report module
39. ART errors Number of responses failed due to invalid length received Number of responses failed due to invalid CRC received Number of responses failed due to invalid slave address Number of responses failed due to invalid function code Number of responses failed due to invalid query data Number of responses received after timeout 15 16 17 18 The first 8 bytes of the most recent query 5 10 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A MODBUS Slave Operation for RX3i Serial Communications Modules For a port in MODBUS Slave mode the module acts on behalf of the CPU to respond to queries from the MODBUS Master over the serial bus as they are received How the Module Handles a Read Request in Slave Mode If the module receives a request to read RX3i CPU data from a MODBUS Master the module follows these steps 1 Each configured exchange is checked for a match If the requested MODBUS Address Target Type and Target Address from Master is not mapped or not valid the module automatically sends a MODBUS exception response on the bus Otherwise 2 If the requested exchange is enabled and valid the module immediately requests the specified data from the CPU 3 After receiving the data from the CPU the module replies to the request by sending a response to the master 4 The module updates the exchange completion status The module sets an Exchange St
40. C memory by default A Read Exchange can be programmed in the exchange table to allow local access to the CCM Diagnostic Status Words only not Scratchpad The Master can clear the CCM Diagnostic Status Words by writing zeros to the seven Diagnostic Status words 7 4 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A CCM Slave Operations for the Serial Communications Module Because an RX3i Serial Communications Module can only be used as a CCM Slave this manual does not include detailed information about implementing CCM communications CCM Slave operation for the RX3i Serial Communications Module is summarized below Write Request from the CCM Master The Master can write up to 2K bytes of data to the RX3i CPU A Write Request from the Master starts with a Normal N Enquiry which has the ASCII character N as its first byte The Slave acknowledges the Enquiry with an ACK character or a NAK if the Slave port is busy The Master then sends the slave a 17 byte Header message that specifies the type of communication being requested write target memory address data length s a xolo Slo o E Master A ofr A SIE O S mH o m H u oO LL l Module sends x Slave All Data to RX3i_ E gt 9 After the Slave acknowledges receiving the Header the Master sends the data If there are more than 256 bytes of data the data is sent in multiple blocks each with the format shown above All data bl
41. FK 2460A Input Data Definitions Exchange Response Report Input Bits 1 64 Bytes 1 8 The Exchange Response Report bits reflect the execution status of the configured communications MODBUS Master For Read or Write Continuous exchanges if this bit is 1 the last execution of the exchange completed successfully If this bit is 0 the last attempt has either failed or not yet completed For Read or Write Continuous Bit Controlled exchanges if this bit is 1 the last exchange attempt completed successfully If this bit is 0 the last attempt has either failed or not yet completed or the control bit was set to 0 during the last output scan causing no exchange to be attempted For a read or write single one shot exchange if this bit matches the corresponding Exchange Control output bit in the output status data the exchange has completed successfully If this bit does not match the output data the exchange is still pending When the bit changes to match the commanded state the exchange is complete MODBUS Slave If this bit is 0 the exchange failed or has not yet executed If this bit is 1 the last execution of the exchange completed successfully Serial I O only the first two Exchange Response bits are used If bit 1 matches the corresponding Control bit a new Serial I O receive has completed If this bit does not match the output data the receive is still pending When the bit changes to match the commanded state the receive is
42. GE Fanuc Automation Programmable Control Products PACSystems RX3I Serial Communications Modules User s Manual GFK 2460A March 2007 GFL 002 Warnings Cautions and Notes as Used in this Publication Warning notices are used in this publication to emphasize that hazardous voltages currents temperatures or other conditions that could cause personal injury exist in this equipment or may be associated with its use In situations where inattention could cause either personal injury or damage to equipment a Warning notice is used Caution notices are used where equipment might be damaged if care is not taken Note Notes merely call attention to information that is especially significant to understanding and operating the equipment This document is based on information available at the time of its publication While efforts have been made to be accurate the information contained herein does not purport to cover all details or variations in hardware or software nor to provide for every possible contingency in connection with installation operation or maintenance Features may be described herein which are not present in all hardware and software systems GE Fanuc Automation assumes no obligation of notice to holders of this document with respect to changes subsequently made GE Fanuc Automation makes no representation or warranty expressed implied or statutory with respect to and assumes no responsibility for the accur
43. MODBUS is a query response protocol The MODBUS Master sends a query to a MODBUS Slave which responds A slave cannot send a query it can only respond After powerup the Master goes into idle mode The Master can only send messages while it is in idle mode After sending a request the Master waits for a reply A Response timeout starts If no reply is received within this time an error is generated and the Master goes back to the idle state The response timeout must be set long enough for any slave to process the request and return the response A timeout can be configured for the port as described in chapter 3 Configuration 5 2 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A The query response transaction completes when the master receives a well formed response After receiving a reply from the slave the Master checks the reply Normal Response After the slave performs the function requested by the query it sends back a normal response for that function This indicates that the request was successful Error Response If the slave receives a query but for some reason it cannot perform the requested function it sends back an error response to the master indicating the reason the request could not be processed No error message is sent for certain types of errors See chapter 4 for a list of error codes Broadcast Messages The MODBUS master sends a broadcast message addressed to all slaves by using addre
44. Num F ata Exchange Num C ata Exchange Num ata Exchange Num C Data Exchange Num Default Data Exchanges Up to 64 data exchanges can be configured for the MODBUS Slave Note that during operation the module will scan the exchanges from 1 to 64 and select the first match for the Master query If the default exchanges are used without being edited they will match any query the Master might send so any additional exchanges will never be reached Some of the default exchanges must be changed or disabled to use additional exchanges If the default exchanges are suitable for the application no additional slave exchanges need to be configured Configure the following parameters for each additional exchange that might be received by the MODBUS Slave port 3 16 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A PLC Access Specify whether the exchange is disabled or if the MODBUS Master should have Read Only or Read Write access to RX3i CPU memory If Read Only or Read Write is selected configure the data mapping for the exchange as described below Target Type Specify the type of MODBUS memory in the master that will be exchanged The Default is Coils Ox Alternatives are Discrete Inputs 1x Input Registers 3x and Holding Registers 4x If PLC Access is configured as Disabled Target Type is read only Target Address Enter a value from 1 to 65535 This is the offset within the Tar
45. O immediately updates the module s I O data when the function executes in the application program Both of these functions operate according to the standard for PACSystems controllers and modules The data that is updated by DO O is the data that is the Port Status Data and Port Control Data described in this chapter DO I O cannot be used with serial communications data which is not part of the normal I O Scanning process The PLC CPU and Serial Communications modules do not permit back to back DO I O commands or normal output scans to overwrite output data before the module can read it If output DO I O will overwrite the previous output data that has not yet been consumed by the module the DO I O will discard the outputs and NOT pass power flow The application must retry output DO I O until successful or retry later DO I O Function Block Format The DO I O function has four input parameters and one output parameter When the function receives power flow and input references are specified the input points starting at the reference ST and ending at END are scanned If an input reference is specified with no alternate destination all of the module s input data is updated Overwriting of all previous input data is only supported when no alternate location is specified If a reference is specified for ALT a copy of the new input values is placed in memory beginning at the alternate reference and the regular input points are not updated
46. Q T Vl Prevent the MODBUS Master from writing to some or all memory in the RX3i CPU Limit MODBUS Master access to certain memory areas and types Target specific data items to be read or written The process of creating custom Data Exchanges is explained in this chapter GFK 2460A Chapter 3 Configuration 3 15 Setting Up MODBUS Slave Data Exchanges Data Exchanges set up specific communications between a Serial Communications Module and its local RX3i PLC CPU over the RX3i backplane MODBUS Module MODBUS Master Communications When a port is set up for MODBUS Slave operation a set of default Data Exchanges is provided for that port that will permit the MODBUS Master to read or write all locations in R and Q memory and read l and AI memory as well as the eight Exception Status bits in Q memory in the PACSystems CPU The default Data Exchanges are shown below These Data Exchanges match any request the module might receive from the MODBUS Master The Ref Length of 0 for the default exchanges means there is no length restriction the entire CPU table Reference Address type in that Data Exchange is accessible RX3i CPU MODBUS RX3i CPU Access Addressing Addressing an a Settings Port1 Port2 Port3 Port 4 PortData ModbusSlave 1 Power Consumption Data Exchange Ref Length ata Exchange Num Read Write i ata Exchange Num F ata Exchange Num F ata Exchange Num F ata Exchange
47. Signal Description For DCE Required for MODBUS Common Signal Common yes CTS Clear to Send In RTS Request to Send Out RxD Received Data In yes TxD Transmitted Data Out yes Each TxD must be wired with the RxD of the other device RS 232 bus cable should not be terminated Can use either or GE Fanuc RX Serial both of these COM ada Compliant VersaMax i evice ene s Communications Module connections RX3i RX7i Series 90 VersaMax Modular pass RS 232 DB 9Male B25 DBS Female Rutt Ru45 Rid RJ 45 Connector Conector Connector Connector Connector Connector Connector Connector COM GND COM GND CMM 8 5 7 5 7 4 8 8 z CTS RTS C COM GND COM GND 7 4 8 4 6 i 5 5 7 5 7 3 5 8 1 4 5 RxD TxD a ee a eee RTS CTS 5 E a a a ey 8 5 7 5 1 6 2 6 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A MODBUS Multidrop Connections For a multidrop MODBUS connections in an RS 485 system either two wire or four wire At least 32 devices can be used without a repeater Depending on the load and the line polarization see below more devices may be possible without a repeater Repeaters can be used when more devices are required An RS 485 MODBUS serial line without a repeater has one trunk table Devices can be connected either directly or using short branch
48. Slave refer to the documentation for the MODBUS Master system for information on implementing MODBUS communications On a MODBUS serial line the Master operates as the client and the slaves operate as servers The Master issues explicit commands to one of the slaves and processes responses Slaves do not typically transmit data without a request from the master and they do not communicate with other slaves The MODBUS Master does not have a specific address on the bus only slaves have addresses A MODBUS network has one master device and one or more up to 247 slave devices A serial network interconnects all these devices If there is only one slave a point to point connection is used A multidrop connection is needed for two or more slaves Unicast or Broadcast Messages The master can issue requests in two modes Unicast the master sends a message to a single slave by specifying its unique address 1 247 on the serial bus After receiving and processing the request the slave returns a reply message to the master In unicast mode a MODBUS transaction consists of two messages a request from the master and a reply from the slave Broadcast the master sends a message to all slaves by specifying the broadcast address 0 Broadcast requests are always write messages Slaves do not respond to a broadcast message The MODBUS Master does not have a specific address on the bus only slaves have addresses Messages and Responses
49. The second execution is complete when the input status bit becomes 0 again Write Periodic Bit Control This type of exchange writes to the specified slave continuously for as long as the corresponding Exchange Control Bit is set to 1 4 10 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Write Single Bit Control Uses toggle bit operation as described above for Read Single Bit Control This type of exchange writes data to the specified slave only once when the Exchange Control Bit transitions to 1 To be sure the exchange is not missed or unintentionally repeated the Control Bit should remain set to 1 until the module has completed the exchange and notified the CPU by setting the corresponding input Exchange Success Report or Exchange Error Report bits to 1 For Serial I O Only the first two bits are used Receive and Transmits use toggle bits as described for MODBUS Master Read Single Bit Control The CPU can set either of these bits to initiate a new Serial I O packet transmission The CPU must first check state of the corresponding Port Status input bit Bit 1 Receive Packet If the state of the first bit in the Port s Status input data is the same as the current state of the first output bit Receive Packet it means that the previous Serial I O receive has completed The CPU can begin a new receive operation by setting this bit to its opposite state if the Receive Packet output bit is 1 set it
50. a ort 1 Control Data Lenath ort 2 Status Data ort 2 Status Data Length ort 2 Control Data ort 2 Control Data Lenath eneral Settings 0 Scan Set IO Settings These parameters assign CPU reference memory for the port s status and control data which is used to monitor and control communications activities on the port This CPU reference memory is not used for the actual communications data CPU reference memory for that data is assigned in a separate step Port 1 2 3 4 Status Data Reference and Length This reference location can be l M or T memory For each port the length is fixed at 224 bits Port 1 2 3 4 Control Data Reference and Length The reference location can be Q M or T memory For each port the length is fixed at 128 bits If retentive memory Q or M may optionally be set up to be retentive T is non retentive is used for Port Control Data when a power cycle with battery or hot swap occurs the control data remains in memory and is executed by the module on the next PLC output scan or output DO I O unless that data is cleared by application logic General Settings I O Scan Set Selecting I O Scan 1 guarantees that the module s Port Status and Port Control data will be exchanged every I O Scan However any scan set from 1 to 32 can be chosen 3 2 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Configuring a Port for Serial I O Protocol To s
51. a query with function code 22 it automatically reads the contents of the two CPU registers that have been defined in the exchange The module uses the query s AND mask and OR values mask to change the register s current content Result Current Content AND And_Mask OR Or_Mask AND And_Mask Example Hex Binary Current Contents 12 0001 0010 And_Mask F2 1111 0010 Or_Mask 25 0010 0101 And_Mask oD 0000 1101 Result 17 0001 0111 The module returns the revised data to the same CPU registers then replies to the master using the normal response shown above GFK 2460A Chapter 5 MODBUS Communications 5 23 Read Write 4x Register Table Memory MODBUS Function 23 The master can issue MODBUS message Read Write 4x Memory to both read and write data in one MODBUS transaction The function writes new contents to one group of registers and returns the contents of a different group of registers Master Device rnin Starting Number of Starting Number of Register to Registers to Register to Registers to uer g g g g Error Check Q y Address 23 Read Read Write Write Slave Device meenen Byte Count Normal Address 23 Error Check Response RX3i Serial Communications Module Port in MODBUS Master Mode This function is not supported by an RX3i Serial Communications module port configured for MODBUS Master mode RX3i Serial Communications Module Port in MODBUS Slave Mode Using the defau
52. acy completeness sufficiency or usefulness of the information contained herein No warranties of merchantability or fitness for purpose shall apply The following are trademarks of GE Fanuc Automation Inc Alarm Master Genius ProLoop Series Six CIMPLICITY Helpmate PROMACRO Series Three CIMPLICITY 90 ADS Logicmaster PowerMotion VersaMax CIMSTAR Modelmaster PowerTRAC VersaPoint Field Control Motion Mate Series 90 VersaPro GEnet PACSystems Series Five VuMaster Proficy Series One Workmaster Copyright 2007 GE Fanuc Automation North America Inc All Rights Reserved Chapter 1 Chapter 2 Chapter 3 GFK 2460A Contents Introduction esos coacttec beset ccetec tres ctevebecstecctecstecerecetcrstac dts caceceteccra nenene nnna 1 1 Introduction to PACSystems RX3i Serial Communications Modules n 1 2 Module Specifications c iszcAclececitlabeteeteadiecie ladeiedieds cecaeidd ects aaa dd aa a aaa aa 1 3 Communications Standards cccccccccsceecceceeeeeseeecceeeeeeeeeeseseceeeeeeeeeseesesieaeeeeeess 1 4 Introduction to Installing Serial Communications Modules ccceeeeeeeeeeseeeeeeenteeeeeeaes 1 5 MODBUS Multidrop RS 485 00 0 cece ee eeneee ee eene ee ee teee ee teeeee sees eeseeeeesnaeeeeeee 1 5 Introduction to Serial Communications Module Configuration 0 ccceeeeeeeeeesteeeeenaes 1 6 Introduction to Serial Communications Module Data cccccccecceeceeeeeeeeeeeeeeeeeeeeeees 1 7 Statu
53. ading Input Data Writing Serial I O Data Dialing a Modem GFK 2460A 6 1 sl Serial I O Communications for RX3i Serial Communications Modules PACSystems RX3i Serial Communications modules support the same Serial I O protocol as the RX3i CPU Serial I O protocol can be used to communicate with a serial device such as a modem connected to one of the module s ports The module has a 2048 byte buffer to receive data from a serial device Serial I O Features of Serial Communications Modules PACSystems RX3i Serial Communications modules provide the Serial I O protocol features listed below Unlike the PACSystems RX3i CPU RX3i Serial Communications modules do NOT use Communication Request COMMREQ commands for Serial I O Instead the CPU sets up data communications in the port s configuration parameters and controls communications through the status and control data that it exchanges with the module each I O Scan detailed in chapter 5 Status and Control Data For reference the table below compares the Serial I O functions implemented using COMMREQs in an RX3i CPU with the same functions for an RX3i Serial Communications module PACSystems RX3i CPU RX3i Serial Communications Module Local functions do not receive or transmit data through the serial port Initialize Port Set bit 67 port reset in the Port s Control Data to 1 Set Up Input Buffer No action necessary The module automatically maint
54. age to preset a group of up to 127 contiguous registers in one slave or all slaves to a specified value Device Function Starting Number Master Register of Data Error Check Query Number Registers Slave Device Function Starting Normal Register Response Number Registers RX3i Serial Communications Module Port in MODBUS Master Mode An RX3i Serial Communications module automatically forms a Preset Write Multiple Registers query function code 16 from a Write exchange that has a Target Type of Holding Registers 4x The module requests the content of the configured CPU references addresses to be written in the query The starting register number configured Target Address can be any value less than the highest register number available in the slave The number of registers configured Reference Length specifies the number of registers to write The sum of the starting register number configured Target Address and the configured Reference Length must be less than or equal to the highest register number available in the slave As soon as the module receives the data highlighted above from the CPU it directs the query to the device address configured Station Address of the slave RX3i Serial Communications Module Port in MODBUS Slave Mode Using the default Data Exchanges the Serial Communications module automatically writes to the CPU R registers The starting reference address and length are spec
55. ains a 2K memory buffer for Serial I O data Flush Input Buffer Set bit 83 flush input buffer in the Port s Control Data to 1 Read Port Status Check the status bits in the Port s Status Data Write Port Control Set bit 84 activate RTS in the Port s Control Data to 1 Cancel COMMREQ Operation Not needed you can cancel a pending receive or transmit by using bit 81 to cancel a receive or bit 82 to cancel a pending transmit Remote functions receive and or transmit data through the serial port Autodial Use multiple write operations of different lengths to dial the modem send the data and send the hang up sequence Write bytes Toggle bit 2 of the Port s Control Data to initiate write Read bytes Toggle bit 1 of the Port s Control Data to initiate read of specific data length Read String Toggle bit 1 of the Port s Control Data to initiate read up to specified termination sequence 6 2 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Local Serial I O Operations Local Serial I O operations are performed by the CPU using the port s control output data The CPU automatically sends this data to the module each CPU sweep It can also be sent using a DO I O block in the application program Details of the Port Control Output data are provided in chapter 4 Port Status and Control Data Initializing Resetting the Port Resetting a port
56. atically supplies the Device Address Function Code and Error Check portions of the basic MODBUS message as indicated in the diagram Only the optional data portion of the message highlighted above and in the individual message descriptions in this chapter must be handled by the application logic in the CPU The Device Address field identifies the slave that will receive the data transfer An RX3i Serial Communications module automatically supplies this portion of a MODBUS message from the Station Address that is configured as part of each exchange that is set up for the port in MODBUS Master mode The Function Code field is a predefined number that identifies the MODBUS query type In MODBUS Master mode an RX3i Serial Communications module automatically determines the correct Function Code to use based on the configured parameters of the exchange No application programming is needed to provide this information The module also automatically performs the error checking function A 16 bit error check Cyclic Redundancy Check is included as the final field of each MODBUS query and response to ensure accurate transmission of data This error check is applied to the entire message frame as shown above It is independent of any parity checking that is done if configured on the individual characters within the message 5 4 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A MODBUS Data Addressing The MODBUS protocol
57. ations Module keep a running total of errors Diagnostic Status Words are independent for each port i oo Byte 1 Spare Byte 2 Most Recent Error Code see next page ooa Number of Successful Conversations serial communications via the port Number of Aborted Conversations m Diagnostic Status Words can be accessed in two ways From the Master by reading the Diagnostic Status Words Target Memory Type through the serial port From the local CPU using the Read Data Exchange in the Port Data CCM Slave tab not through the serial port Diagnostic status words can be cleared in two ways From the Master by writing zeros over the Diagnostic Status Words Target Memory Type through the serial port From the local CPU by setting the Clear CCM Errors bit not through the serial port 7 8 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Error Codes in the Diagnostic Status Words Error Code Description za Successful Transfer 01 A time out occurred on the serial link 03 An external device attempted to read or write a non existent I O point bit 04 4 An external device attempted to access more data than is available in a particular memory type An external device attempted to read or write an odd number of bytes to Register memory or the Diagnostic Status Words An external device attempted to read or write one or more a non existent Registers An external device specified the transfer
58. atus Report bit to 1 if the exchange was successful If the exchange was unsuccessful the module sets the Exchange Status Report bit to 0 and updates additional status information for the exchange as detailed in chapter 4 Port Status and Control Data How the Module Handles a Write Request in Slave Mode If the module receives a request to write RX3i CPU data from a MODBUS Master the module follows these steps 1 Each exchange is checked for a match If the requested MODBUS Address Target Type and Target Address from Master is not mapped or not valid the module automatically sends a MODBUS exception response on the bus Otherwise 2 If the requested exchange is enabled and valid the module immediately sends the data to the CPU 3 The module sends a normal response to the master 4 The module updates the exchange completion status as detailed in chapter 4 Port Status and Control Data GFK 2460A Chapter 5 MODBUS Communications 5 11 MODBUS Functions for RX3i Serial Communications Modules This section describes each MODBUS function that is supported by RC3i Serial Communications modules and explains how to implement the function for a Serial Communications module in master or slave mode Read Coil Status Read Output Table MODBUS Function 01 The master can direct a MODBUS Read Coil Status message to a specified slave to read up to 254 bytes of data from the slave s discrete outputs coils Ox table The query and normal
59. bits in the CPU s Q reference table If a new exchange is configured the PLC Access mode may be either Read Only or Read Write The Target Type must be Coils 0x The Target Address is the offset from the start of the Master s Coils table The configured Reference Address and Reference Length specify the CPU location of the data available to be read The module receives the requested data from the CPU then immediately sends it to the MODBUS Master using a Normal Response as shown above 5 18 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Diagnostics Return Query Data MODBUS Function 08 The master can direct a MODBUS Diagnostic Loopback Maintenance query to a specified slave to test the slave s ability to mirror the same data back to the master The query and normal response formats are Device Function Diagnostic i Master brie Query ode l i i 1 i Device Function Diagnostic Response Gade 00 RX3i Serial Communications Module Port in MODBUS Master Mode An RX3i Serial Communications Module automatically forms a Diagnostics query function code 08 with a Diagnostic Code of 00 from a Read Exchange that has a Target Type of Return Query Data The module requests from the CPU two bytes of data from the configured Reference Address location The values of the two data field bytes in the query are arbitrary After receiving the data from the CPU the module directs the query to the slave
60. ble shields at one end only to eliminate ground loop currents is not recommended because it increases the network s susceptibility to intermittent data errors from electromagnetic interference EMI Such errors can be difficult to detect and costly to correct If data errors caused by ground loops cannot be avoided for example because the cable run is too long for all devices to use a common ground point add one or more optically isolated RS 485 repeaters to the network Partition the network into segments so that each segment has a common ground Isolate the segments with repeaters 2 8 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Multidrop Connections for Four Wire MODBUS Four wire bus cable includes two pairs of communications lines and a common line Data on the master pair RxD1 RxDO is received by only the master Data on the slave pair TxD1 TxDO is received by only the slaves Only one driver at a time has the right to transmit The MODBUS slave devices must all use RS 485 compatible serial ports so that their transmitters are disabled except when transmitting Although some RS 422 devices disable outputs when not transmitting the RS 422 specification does not require it The master may use either RS 422 or RS 485 because it is the only transmitter on that pair Any high quality shielded twisted pair cable with two pairs is suitable for short cable runs up to about 15 meters without repeaters Long
61. cables up to 20 meters If a multi port tap is used each branch has a maximum length of 40 meters divided by the number of branches fed by that tap The length of the bus cable depends on the baud rate the number of loads the type of cable and the network configuration For a maximum 9600 baud rate and AWG28 or larger cable the maximum length is 1000 meters AWG24 is always sufficient for MODBUS data Category 5 cables may be used up to a maximum length of 600 meters In a system where four wire cabling is used in a two wire system as shown in this section the maximum cable length must be divided by 2 For the balanced pairs in an RS 485 system a characteristic impedance above 100 Ohms is preferred especially for baud rates of 19200 and above The line must be terminated near both ends of the bus trunk cable between the DO and D1 conductors of the balanced line Termination must not be placed on a branch cable 150 Ohm 1 2W resistors can be used for termination In a four wire system each pair must be terminated at each end of the bus The signal and optional power supply common signal must be connected directly to protective ground preferably at one point only This is usually done at the master or its tap GFK 2460A Chapter 2 Installation and Wiring 2 7 Grounding and Ground Loops Proper grounding of the cable shield requires careful planning of the network and its power wiring To avoid data errors from intermittent electri
62. cal noise the cable shield must be grounded to earth ground at every device on the network Unfortunately this introduces at least N 1 ground loops where N is the number of devices on the network Each ground loop path comprises the shield and drain wire on the cable segment between two devices and a ground return path The return paths start at the frame ground point of one device pass through its ground conductor to the common ground and then pass through the ground conductor of the other device to its frame ground point Ground loop currents must be kept within acceptable limits by careful grounding Otherwise common mode noise induced on the data pair by the ground loop currents can cause data errors When designing ground wiring consider these requirements 1 There must be one common ground point in the system with an extremely low impedance path to earth 2 The conductor from the frame ground point of each device to the common ground must have extremely low impedance 3 The recommended frame ground wire sizes lengths and proper wiring practices must be observed in designing the connections between frame ground points and the common ground 4 The data cable and ground wire routing must be physically isolated from other wiring that could couple noise onto the data cable or ground wiring 5 If disconnecting the cable shield from earth ground at any device reduces data errors the network has a ground loop issue Connecting ca
63. cations cccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeneeeeeeeeeeeeeees 5 1 MODBUS Communications Overview cceceeececeeceeeeeeeeeeeeeaeceeeeeeeseceneaeeeeeeeeetensnnaeees 5 2 Unicast or Broadcast MeSSages eeececeeeseeeeeeeeneeeeeeeneeeeeeaeeeeeeaeeeeeeaeeeeeenaeeeeeeaas 5 2 Messages and Responses ccccecseereeee sence ee eeneeeeeeaieeeeeteeeeesiieeeeetieeeeetneeeeeeaa 5 2 MODBUS Message Formals misuri reii i TAT R 5 4 MODBUS Data Addressing 0 ecccceccneeeeeeeneee ee etteee ee tieee ee teeeeeteeeeetaeeeeetaeeeeeeaa 5 5 MODBUS Communications for RX3i Serial Communications Modules 000 5 6 Supported MODBUS Functions ceccceecccceceeeeeeeeceeceeeeeeeseccaeaeeeeeeeeeesesecnieaeeeseess 5 6 Supported Transmission Modenesi aa aaa e eaaa aai ENEA 5 6 How MODBUS Functions are Implemented c cccccceeceeceeeeeeeeeeeeaeeeeeeeeeteees 5 7 MODBUS Master Operation for RX3i Serial Communications Modules 00000000 5 8 How the Module Handles a Write Request in Master Mode cceeeeteeeeees 5 9 How the Module Handles a Read Request in Master Mode ceeeeeetetees 5 9 MODBUS Master Diagnostics ce eceeeeceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeneaeeeseeaeeeetenaaeees 5 10 MODBUS Slave Operation for RX3i Serial Communications Modules c000000 5 11 How the Module Handles a Read Request in Slave Mode sc
64. complete If bit 2 matches the corresponding Control bit a new Serial I O transmit has completed If this bit does not match the output data the transmit is still pending When the bit changes to match the commanded state the transmit is complete CCM Slave For PLC Access of Read Only Read Write or Write Only if this bit is 1 the last exchange attempt completed successfully If this bit is 0 the last attempt has either failed or not yet completed or the control bit was set to 0 during the last output scan causing no exchange to be attempted For all other types or PLC Access if this bit is 1 the last execution of the exchange completed successfully If this bit is 0 the last attempt has either failed or not yet completed GFK 2460A Chapter 4 Port Status and Control Data 4 5 Exchange Error Report Input Bits 65 128 Bytes 9 16 The Exchange Error Report input bits reflect the error status of the configured communications For MODBUS Master or Slave and CCM Slave the 64 Exchange Error Report bits report the error status of the configured exchanges For each exchange if the corresponding bit is 1 an error occurred for that exchange The bit remains set until one of the following occurs The error is acknowledged by the application setting the Port Error Exchange Selector to the exchange number Port Control bits 73 80 and the Port Command bit 65 to 1 All errors are cleared by the application setting Port Command bit 66 The
65. connected in parallel to a single pair of wires Both ends of the pair must be terminated with 120 ohm resistors All devices must be RS 485 compatible in order to disable their transmitters except when transmitting All devices must disable their receivers while transmitting The signal pair must be terminated at both ends If either end device lacks a built in terminator a recommended 120 ohm watt resistor must be wired across the signal pair inside the connector shell Any high quality shielded twisted pair cable is suitable for short cable runs up to about 15 meters Longer runs require a cable with a suggested nominal impedance of 120 ohms Use a cable designed for RS 485 transmission such as Belden 3105A or equivalent Serial ports on all devices should be configured for Flow Control NONE RS 485 repeaters can also be used on 2 wire networks Connections for Two Wire Devices Two wire bus cable includes two communications lines and a common line Only one driver at a time has the right to transmit MODBUS Master Gi Common Termination Termination GFK 2460A Chapter 2 Installation and Wiring 2 11 Connecting Four Wire Devices to a Two Wire Network Four wire devices can be connected to a two wire network as shown below In this example the master and slave 1 use a two wire interface Slaves 2 and 3 use a four wire interface MODBUS Master Termination Termination For each four wire d
66. converted to their hexadecimal equivalents as shown below for the example values 0x41 a b c is converted to 0x41 0x61 0x62 0x63 aa is converted to 0x61 0x61 0x41 remains 0x41 0x41 0x42 0x43 0x44 remains 0x41 0x42 0x43 0x44 3 6 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Serial I O Write Configuration Write Control Operation Default is Transmitting Disabled Alternative is Transmitting Enabled Serial 1 0 Write Configuration wits Cowie Goa Write Serial 1 0 Memory Area Write Serial 1 0 Data Length HRE fan Seance Static Write Length For Transmitting Enabled configure the additional parameters shown Write Serial I O Memory Area Specify the beginning reference in CPU memory for the data that will be written to the serial device Memory types are AI AQ R M Q l Write Serial I O Data Length Default is 0 Range is 0 to 1024 The length in 8 bit increments or 16 bit words as appropriate for the CPU reference area that will be used for Serial I O transmitted data The length must accommodate the largest amount of data that may be sent in one transaction Write Length Source If the same length of data will always be written choose Static Write Length and enter a value below If the write length may change choose Dynamic Write Length Found in Output Scan Data The CPU must then provide the data length in bits 113 128 of the Port Control output data it sends
67. d by configuring a Data 6003 Exchange to read Diagnostic Status data from Diagnostic Statu S Mord ron GEM the module to a memory location in the RX3i interface to CPU CPU CCM Command number not supported This 6004 Software Configuration Local command function is handled by port configuration in Machine Edition 6101 Read from Target slave to Source CCM Master Register Table Read Write Register Table Data Exchange sets 6102 Read from Target slave to Source up CCM Master reads to any specified RX3i CCM Master Input Table memory area as configured Multiple memory 6103 Read from Target slave to Source areas and types can be configured CCM Master Output Table Read Q Response to Source Output The module returns the requested data to the 6109 Table Master Single Bit Write This function writes one Configured Data Exchanges in the Serial bit to l or Q Bit may be set to 1 or Communications Module define Input Table B 6110 cleared to 0 depending on the memory set and or clear and Output Table Bit set type specified as explained in the CCM and or clear Multiple memory areas and types Master documentation can be configured Write to Target from Source Register 6111 Table This function writes a specified number of words from Master to R Register Table F Read Write Register Table Data Exchange sets 6112 write to Target from Sour e Input Table up CCM Master writes to any specified RX3i This funct
68. d communications data which is explained in more detail in chapter 4 To write data to a Serial I O device the application should 1 Application program toggles Port Control output bit 2 to the opposite state to initiate the next packet transfer The Serial Communications module responds by immediately requesting the contents of the configured Serial I O transmit references from the CPU the data should not be changed until the operation is complete For example Data Values 6568 h 68h e 65h 6C6C 6Ch T 6Ch 006F o 6Fh Although printable ASCII characters are used in this example there is no restriction on the values of the characters that can be transmitted The amount of data transferred depends on the parameters that were chosen for the Serial I O Write configuration Write Fixed Byte Count If the port s Write Length Source is configured for Static Write Length the module will write the configured number of bytes Write Dynamic Byte Count If the port s Write Length Source is configured for Dynamic Write Length the application sends the number of bytes to be read in the word between bits 113 128 word 16 of the Port Control Data The CPU provides the requested data to the module The status of the operation is not complete until all of the characters have been transmitted or until a timeout occurs for example if hardware flow control is being used and the remote d
69. dled by configuring Data Exchanges as shown in the center column When used in MODBUS Slave mode Serial Communications modules can handle all MODBUS communications automatically with no need to configure Data Exchanges Additional Data Exchanges can be configured as suitable for the application PACSystems RX3i CPU use COMMRE to Perform MODBUS Function RX3i Serial Communications Module in Master Mode Configure a Data Exchange to RX3i Serial Communications Module in Slave Mode Read Coil Status 01 Read up to 254 bytes from the slave s Coils 0x table Read Input Status 02 Read up to 254 bytes from the slave s Discrete Input 1x table Read Holding Registers 03 Read up to 127 words from the slave s Holding Registers 4x table Read Input Registers 04 Read up to 127 words from the slave s Input Registers 3x table Force Single Coil 05 Not available in Master mode Preset Single Register 06 Write one register two bytes of data to the slave s register memory Read Exception Status 07 Read the exception status of the slave by configuring a Target Type of Diagnostic Status Diagnostics 08 diagnostic code 00 Read or write with a Target Type of Return Query Data Write Multiple Coils 15 Write up to 254 bytes of data to the slave s Coils 0x table Preset Write Multiple Registers 16 Write one or more
70. dropped Flow Control for RS232 only Default is none Choices are None or Hardware Control RTS CTS If Hardware Control is specified the port will assert RTS then wait for CTS to become active before transmitting If CTS does not become active within 2 seconds a time out error code is returned to the status location If CTS becomes active and then is de asserted while the port is transmitting up to 5 milliseconds may elapse before transmission stops The maximum number of characters transmitted after CTS is de asserted is proportional to the data rate These values are in addition to the character that is being transmitted at the time CTS is de asserted Outputs Disabled Control Default is Stop Processing Exchanges Alternative is Continue Processing Exchanges MODBUS Slave Port Settings If the Protocol Type is Modbus Slave only select the Station Address of the slave port Range is 1 to 247 Port Config ID Setting User Config ID Default is 1 range is 0 to 255 3 14 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Automatic MODBUS Slave Exchanges Proficy Machine Edition 5 6 SIM 6 or later provides a set of default Data Exchanges that will automatically accommodate all supported MODBUS queries from the master By default when the port is set up for MODBUS Slave operation a set of predefined Data Exchanges map MODBUS addresses to PACSystems CPU reference addresses When the default Data Exchan
71. dule OK LED indicates the status of the module MODULE OK Solid green indicates that the module has been configured HEME Re A The Module OK LED is off if the module is not receiving power from the RX3i backplane or if a serious module fault exists At powerup the Module OK LED flashes green off while the module is executing powerup diagnostics It then flashes more slowly as the module receives its configuration from the CPU If a problem occurs the Module OK LED blinks amber to indicate the cause of the error 1 watchdog expired 2 RAM error 6 Invalid CPU Master Interface version 7 CPU heartbeat failure 8 Failed to get semaphore The Port Fault LED indicates the status of all ports The Port Fault LED is green when there are no faults present on any enabled port If this LED turns amber there is a fault on at least one port Port LEDs Each port has a Status LED that flashes green when there is activity on the port Recording Port Assignments The front of the module has an area where identifying information about each port should be written GFK 2460A Chapter 2 Installation and Wiring 2 3 Serial Ports RX3i Serial Communications modules provide either 2 or 4 identical serial ports that can be individually configured for RS 232 or RS 485 operation Port Pin Assignments Each port is a standard RJ 45 female connector with the following pin assignments For MODBUS applications note that these pin assignmen
72. dules LEDs Module LEDs Port LEDs Serial Ports Port Pin Assignments Built in Termination Point to Point Serial Connections RS 232 MODBUS MODBUS Multidrop Connections Grounding and Ground Loops Multidrop Connections for Four Wire MODBUS Multidrop Connections for Two Wire MODBUS For additional module installation and system installation information please refer to the PACSystems RX3i System Manual GFK 2314 GFK 2460A Installation in Hazardous Locations The information below applies to modules that are installed in hazardous locations For more information about standards compliance please refer to Appendix A of the PACSystems RX3i System Manual GFK 2314 EQUIPMENT LABELED WITH REFERENCE TO CLASS GROUPS A B C amp D DIV 2 HAZARDOUS LOCATIONS IS SUITABLE FOR USE IN CLASS I DIVISION 2 GROUPS A B C D OR NON HAZARDOUS LOCATIONS ONLY WARNING EXPLOSION HAZARD SUBSTITUTION OF COMPONENTS MAY IMPAIR SUITABILITY FOR CLASS I DIVISION 2 WARNING EXPLOSION HAZARD WHEN IN HAZARDOUS LOCATIONS TURN OFF POWER BEFORE REPLACING OR WIRING MODULES AND WARNING EXPLOSION HAZARD DO NOT CONNECT OR DISCONNECT EQUIPMENT UNLESS POWER HAS BEEN SWITCHED OFF OR THE AREA IS KNOWN TO BE NONHAZARDOUS 2 2 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A LEDs RX3i Serial Communications provide visual indication of module and port status with the LEDs described below Module LEDs The Mo
73. e references If the Data Exchange Target Type is Return Query this reference should specify the start of two bytes of data to be sent to the specified slave The content of the data is not meaningful its purpose is to verify the slave s data to return the query Available FL ow Limit 1 High Limit 64 End ZAL00064 Cancel Help Reference Length Specify the length of the memory area selected above in bits or 16 bit words registers The default is 0 Range is 1 to 127 words or 1 to 2040 bits For Diagnostic Status this is fixed at 18 words 240 bits For a Return Data Query the length of this data area should be 16 bits 1 word 3 12 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Configuring a Port for MODBUS Slave Protocol On the port tab set Protocol to MODBUS Slave then configure the additional port parameters as described below Settings Port 1 Port 2 Port 3 Port 4 PortData_ModbusSlave 1 Power Co Parameters Serial Port Settings ata Rate ata bits arity top bits imeout mS t utputs Disabled Control MODBUS Slave Port Settings tation Address Port Config ID Setting ser Contig ID 3 ig ll i koa Serial Port Settings Data Rate Default 19 2k Choices are 1200 2400 4800 9600 19 2k 38 4k 57 6k 115 2k baud Data bits This is always 8 for MODBUS Slave Parity None Odd Even When
74. e port can safely transmit If CTS does not become active within 2 seconds the module returns a timeout error to the status location After the last transmit character is sent the CPU must set the RTS bit to 0 If CTS becomes active and then is de asserted while the port is transmitting up to 5 milliseconds may elapse before transmission stops The maximum number of bytes transmitted after CTS is de asserted is proportional to the data rate These values are in addition to the byte that is being transmitted at the time CTS is de asserted Data Rate Maximum Number of Characters Data Rate Maximum Number of Characters Received after CTS is De asserted Received after CTS is De asserted 1200 1 19200 10 2400 2 38400 20 4800 3 57600 29 9600 5 115200 58 Bits 161 to 176 number of input buffer characters available is a data word containing the number of input buffer bytes available in the module to receive data from the serial device If there are no characters in the port s input buffer the module ends the receive operation immediately The module then sets the port s Exchange Error Report bit to 1 and the received character count next item to 0 The CPU is responsible for reading serial data out of the buffer to make room for new data Bits 177 to 192 number of characters received is a word of data that contains the number of bytes received by the module Error Status Exchange Number Input Bits
75. eaeeeeeeesetennueaeeeeeess 7 5 Normal Read Request from the CCM Master ccccccseeeeceeceeeeeeeeeeaeeeeeeeeeeeenaees 7 6 Quick Read Request from the CCM Mastet ccceceeeseeceeeeeeeeeeeseeneeeeeeeeeteees 7 6 Scratchpad Data ss ennaa ea a e tee ena ea Aneta ea eo ee 7 7 Diagnostics Data for CCM Slave Ports ssssseseessseieesesrrssttrrssttrrssttnresttnrssttnnssttnnnsttennnnt 7 8 TransmissioM ETOS mig e a a aae cece tind it e a e al et 7 9 GFK 2460A Contents v Contents vi PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Chapter Introduction l This chapter is an introduction to the PACSystems RX3i Serial Communications modules Introduction to PACSystems RX3i Serial Communications Modules Module Specifications Communications Standards Introduction to Installing Serial Communications Modules Introduction to Serial Communications Module Configuration introduction to Serial Communications Module Data Status and Control Data Serial Communications Data Introduction to MODBUS Communications Supported MODBUS Functions Supported Transmission Mode Introduction to Serial I O Communications Introduction to CCM Slave Communications Additional Documentation PACSystems Serial Communications Modules IC695CMM002 and IC695CMM004 GFK 2461 This datasheet type document contains the same module descriptions and specifications found in this user manual plus the m
76. eceeeeeeeeeees 5 11 How the Module Handles a Write Request in Slave Mode eceeeeeeeeees 5 11 MODBUS Functions for RX3i Serial Communications Modules ccceseeeeeeees 5 12 Read Coil Status Read Output Table MODBUS Function 01 1 0 eee 5 12 Read Input Status Read Input Table MODBUS Function 02 eeee 5 13 Read Holding Registers Read Registers MODBUS Function 03 eee 5 14 Read Input Registers Read Analog Inputs MODBUS Function 04 5 15 Force Single Coil MODBUS Function 05 cccccccececeeeeeeceeeeeeeeeteceeeeeeeeeeeeenenas 5 16 Preset Write Single Register MODBUS Function 06 ee cceeeeeeeeeeeeeeeeeeeeneeees 5 17 Read Exception Status MODBUS Function 07 ccccceseseseseeesseeeeseeeeeeeneees 5 18 Diagnostics Return Query Data MODBUS Function 08 ceseeeeeeeeeeeees 5 19 Write Multiple Coils Force Multiple Outputs MODBUS Function 15 5 20 Preset Write Multiple Registers MODBUS Function 16 ccccceeeeeeeereeeeees 5 21 iv PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Contents Report Slave ID MODBUS Function 17 ccccccesesesesessseseseseseseeesesseeseseeeeeeeees 5 22 Mask Write 4x Memory Register Table MODBUS Function 22 00 00 eee 5 23 Read Write 4x Register Table Memory MODBUS Function 23 eee 5 24 Chapter 6 Serial O C
77. ed Read Continuous Read Continuous Bit Control Read Single Bit Contral Read Onl Read Write Write Only Disabled the exchange number is not defined Read Continuous Read Continuous Bit Control Read Single Bit Control These three PLC Access Types set up local data exchange between the Serial Communications Module and its RX3i CPU The RX3i CPU will read the module s seven CCM Status Words and place them into the specified Reference Address The format of this data is shown in chapter 7 Depending on the PLC Access selected CCM Status Words can be read continuously continuously with application program control or once with application program control Here the port is set up for continuous reading of its CCM Status Words which will be placed into RX3i CPU memory starting at Reference Address R00065 Data Exchange Number 10 l GFK 2460A Chapter 3 Configuration 3 21 The CCM Master can always access seven Diagnostic Status Words using a CCM Read command to that target memory type The CCM Master can also clear the CCM Status Words in the PLC CPU by writing zeros to that target memory type Read Only Read Write Write Only These three PLC Access Types define how the application program can access the CCM Diagnostic Status Words To read the seven Diagnostic Status words in the local RX3i CPU directly from the slave an exchange of this type must be used The local RX3i CPU can always clear these D
78. egister number value and the number of registers value must be less than or equal to the highest register number in the slave When all of the data has been received from the MODBUS Slave the module automatically writes the data highlighted above to the configured CPU Reference Address area and updates the exchange status information RX3i Serial Communications Module Port in MODBUS Slave Mode Using the default Data Exchanges the module automatically requests from the CPU an area of the Al reference table The starting reference address and length are specified in the master s query If anew exchange is configured he PLC Access mode may be either Read Only or Read Write The Target Type must be Input Regs 3x The Target Address is the offset from the start of the Master s Input Registers table The configured Reference Address and Reference Length specify the CPU location of the data available to be read The module receives the requested data from the CPU then immediately sends it to the MODBUS Master using a Normal Response as shown above GFK 2460A Chapter 5 MODBUS Communications 5 15 Force Single Coil MODBUS Function 05 The master can issue a MODBUS Force Single Coil message to a specified slave or to all slaves to change the state of one point in the discrete outputs coils Ox table The specified output is forced automatically This command is not an output override command The output is guaranteed to be f
79. egisters 3x MODBUS Holding Registers 4x MODBUS Query data or Diagnostic Status data If Diagnostic Status is selected the CPU can use this exchange to read from the Serial Communications Module a set of Diagnostic Status words for the port See chapter 4 for details of the Diagnostic Status words If Return Query Data is selected the CPU will use this exchange to automatically perform MODBUS function 08 Subfunction 00 Read Query Data The module sends two bytes of data to the specified Slave Address Target Type and Target Address to see whether the slave echoes the data back The data that is sent will be two bytes from the configured Reference Address The content of the data is not meaningful Target Address For MODBUS data this is the starting address in the MODBUS table selected as the Target Type For Diagnostic Status Data this is the first word of Diagnostic Status data to be read from the module For example entering a Target Address of 1 would access Word 1 of the Diagnostic Status data which is the MODBUS Errors status word as detailed in chapter 4 GFK 2460A Chapter 3 Configuration 3 11 Reference Address Specify the CPU memory type and starting address for the data to be read or written in the Data Exchange To select a memory type and starting address double click on the Ref Address field or right click and select Data Entry Tool z Select a starting address 222100033 a Select a memory type Availabl
80. er 5 17 Proficy Machine Edition 1 2 Q Quick Read Request from the CCM Master 7 6 R Read Coil Status 5 12 Read Continuous 3 10 Read Control Operation 3 5 Read Delimiter 3 5 Read Delimiters 3 6 Read Exception Status 5 18 Read Holding Registers 5 14 Read Input Registers 5 15 Read Input Status 5 13 Read Length 3 6 4 12 Read Periodic Bit Control 4 10 Read Single Bit Control 3 11 Read Single Bit Control 4 10 Read Write 4x Register Table Memory 5 24 Receive Checksum 3 4 Receive Packet 4 11 Receiving Disabled 3 5 Reference Address 3 17 3 22 Reference Address Assignment 3 2 Report Slave ID 5 22 Return Query Data 3 11 RS 232 1 2 1 4 RS 232 MODBUS 2 6 RS 485 1 2 1 4 RS 485 MODBUS 2 7 RTS 3 14 3 19 4 12 RTU 1 8 RTU Message Types Broadcast 5 3 S Scan Set 3 2 Scratchpad Data 7 7 Serial Communications Data 1 7 Serial I O Communications 1 9 Serial I O Configuration 3 4 Serial I O Data 6 6 Serial I O Features 6 2 Serial I O Memory Area 3 5 Specifications 1 3 Standards 1 2 Station Address 3 11 Status and Control Data 1 7 4 2 Stop Bits 1 3 3 3 3 8 Suspend I O 4 15 T Target Address 3 11 3 17 3 22 Termination 2 5 2 7 Timeout 3 3 3 8 3 13 Transmission Mode 1 8 5 6 Transmit Checksum 3 4 Transmit Packet 4 11 Turnaround Delay 1 3 Two Wire MODBUS 2 11 U Upgrades 1 2 V Validate Receive Checksum 3 4 Voltage
81. er runs require a cable with a suggested nominal impedance of 120 ohms Both signal pairs must be terminated at both ends by a suggested 120 ohm 1 4 watt resistor across the RxD signal pair Co B 10 KS Master peh e A k xD GFK 2460A Chapter 2 Installation and Wiring 2 9 Connecting the Master Using a Passive Tap Four wire cable must cross the two pairs on the bus between the bus interface and the passive bus tap on the master This may be done with crossed cables but the recommended way to connect a 4 wire master device is to use a tap that provides a crossing capability In Piles 7 P Type meas a ee Slave Pair RxD1 In B TxD1 RxDO In A TxDO Master Pair TxD1 Out B RxD1 TxDO Out A RxDO Connecting Two Wire Devices in a Four Wire System Two wire devices can be connected to a four wire system as shown below In this example the master and slave 1 use a four wire interface Slaves 2 and 3 use a two wire interface MODBUS Master TxD1 Mee Teco Termination Termination The TxDO signal must be wired to the RxDO signal turning them into the DO signal The TxD1 signal must be wired to the RxD1 signal turning them into the D1 signal 2 10 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Multidrop Connections for Two Wire MODBUS On a two wire network the Transmit Data TxD and Receive Data RxD pairs of all devices are
82. et up a port for Serial I O protocol on the Port tab set Protocol to Serial I O then configure the additional port parameters for Serial I O as described below Settings Port 1 Port 2 PortData_SeriallO 1 Power Consumption sl SemlPatSetings DataRate E P Ee me i Ar TWAS Diop Delay ots i Gti al eas Port Config D Seting Serial Port Settings Data Rate Default 19 2k Choices are 1200 2400 4800 9600 19 2k 38 4k 57 6k and 115 2k Baud Data bits Choices 7 8 Parity None Odd Even Stop Bits Default is 1 Choices 1 2 Timeout mS Defaults to 100 Range is 0 to 65535ms If the module is expecting to receive data and it hasn t received data before this assigned timeout period a receive timeout error occurs for the exchange being processed If there is data to be transmitted and the hardware handshaking isn t allowing data to be transmitted CTS not asserted when in RS 232 mode with Hardware Control configured for the assigned timeout value a transmit error occurs for the exchange being processed Port Type RS232 RS485 2 wire RS485 4 wire Tx RTS Drop Delay defaults to 0 Range 0 to 15 This is the time from the end of the last transmitted character to the time when RTS is turned off dropped A Drop Delay may be needed for some modem communication with RTS and long distance RS 485 connections For RS 232 with Flow Control next item a suitable Drop Delay should be co
83. evice The TxDO signal must be wired with the RxDO signal then connected to the DO signal on the trunk The TxD1 signal must be wired with the RxD1 signal then connected to the D1 signal on the trunk 2 12 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Chapter Configuration 3 This chapter describes the configurable parameters of PACSystems RX3i Serial Communications modules Configuring Basic Module Settings I O Settings General Settings Configuring a Port for Serial I O Protocol Serial Port Settings Serial I O Port Data Serial I O Read Configuration Serial O Write Configuration Configuring a Port for MODBUS Master Protocol Serial Port Settings Configuring MODBUS Master Exchanges Configuring a Port for MODBUS Slave Protocol Serial Port Settings Automatic MODBUS Slave Exchanges Configuring MODBUS Slave Exchanges Configuring a Port for CCM Slave Protocol GFK 2460A 3 4 Configuring Basic Module Settings Click on the slot and right click to Add a Module From the module catalog select either of the following from the list of Communications Modules IC695CMMO002 RX3i Serial Communications Module 2 ports IC695CMMO004 RX3i Serial Communications Module 4 ports For the module configure the following settings Settings Port 1 Port 2 PortData_SeriallO 1 Power Consumption Parameters 0 Settings ort 1 Status Data ort 1 Status Data Length ort 1 Control Dat
84. evice never enables the transmission After transmitting all of the data the module updates any error status in the Port Status Data and sets bit 2 of the Port Status input data to the same state as output bit 2 The application logic should monitor status bit 2 When input bit 2 and output bit 2 are the same it indicates that the last transmission was completed successfully 6 6 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A L Dialing a Modem Serial I O writes can be used to dial a modem and send a specified byte string For example pager enunciation can be implemented by three commands requiring three commands Dial the modem Specify an ASCII string to be sent from the serial port Sending the hang up command string It is the responsibility of the application logic to hang up the connection Command Strings to Dial or Hang Up a Modem Commonly used command strings for Hayes compatible modems are listed below ATDP15035559999 lt CR gt 16 10h Pulse dial the number 1 503 555 9999 ATDT15035559999 lt CR gt 16 10h Tone dial the number 1 503 555 9999 ATDT9 15035559999 lt CR gt 18 12h Tone dial using outside line with pause Hang up the phone ATHO lt CR gt 5 05h ATZ lt CR gt 4 04h Restore modem configuration to internally saved values For example these strings tone dial the number 234 5678 using a Hayes compatible modem Data Values 54
85. ges are used no additional slave exchanges need to be configured Following are the RX3i addresses that correspond to MODBUS functions that may be received by the slave port Read Input Registers Al Read Holding Registers R Preset Single Register R Preset Multiple Registers R Mask 4X Registers R Read Write 4X Registers R Read Input Status l Read Coils Status Q Force Single Coil Q Force Multiple Coils Q Changed Implementation of MODBUS Slave Exchanges Earlier versions of Machine Edition such as Machine Edition 5 5 with Service Pack 2 SIM 4 implemented MODBUS Slave Exchanges using the Preconfigured Exchanges field on the port configuration tab Selecting Preconfigured Exchanges set up the automatic mapping described above but prevented configuration of additional Data Exchanges for the port With Machine Edition 5 6 SIM 6 or later the Preconfigured Exchanges field is no longer available The function is replaced by the preconfigured Data Exchanges which provide greater configuration flexibility as described below Customizing MODBUS Slave Exchanges The default Data Exchanges in Machine Edition 5 6 SIM 6 or later permit the MODBUS Master to read all of the l AI Q and R references and to write all of the Q and R references in the PACSystems RX3i CPU The default exchanges can be edited and new Data Exchanges can be defined in order to Read or write additional reference types AI AQ R W M
86. get Type memory for the data to be read written Reference Address Specify the PACSystems memory type and starting address for the data to be read or written in the Data Exchange To select a memory type and starting address double click on the Ref Address field or right click and select Data Entry Tool Reference Address z Select a 2A100033 H ane starting address High Limit 64 E Select a nd vlou memory type N Available references Cancel Help Reference Length Specify the length of the memory area selected above in bits or 16 bit words registers The default is 1 Range is 1 to 127 words or 1 to 2040 bits GFK 2460A Chapter 3 Configuration 3 17 Configuring a Port for CCM Slave Protocol On the port tab set Protocol to CCM Slave then configure the additional port parameters as described below Settings Port 1 Port 2 PortData_CCM_Slave 1 Power Consumption Ati Fiwlniy a CCM Slave Port Settings StationAddess Ea Port Config ID Seting JUserConfigID Meerrr Serial Port Settings Data Rate Default 19 2k Choices are 1200 2400 4800 9600 19 2k 38 4k 57 6k 115 2k baud Choose a baud rate that matches that used by the CCM Master Note that RX3i Serial Communications modules do not support the 300 and 600 baud data rates of CCM hardware modules such as the Series 90 30 CMM311 and CCM hardware modules do n
87. h 2007 GFK 2460A Read Single Bit Control This type of exchange must be initiated by setting a bit in the CPU see chapter 4 for details The module reads the specified data once each time the control bit transitions Write Continuous This type of exchange repeatedly writes the specified bit or word data from the assigned CPU references to the slave s Coils Ox or Holding Registers 4x table The CPU does not control this exchange It only stops when PLC outputs are disabled if the Outputs Disabled parameter on the Port tab is set to disable continuous exchanges when outputs are disabled Write Continuous Bit Control This type of exchange must be started by setting a bit in the CPU see chapter 4 for details The module then periodically writes the specified data to the slave until commanded to stop by clearing the same bit Write Single Bit Control This type of exchange must be initiated by setting a bit in the CPU see chapter 4 for details The module writes the specified data once each time the control bit transitions Station Address Specify the MODBUS Device ID from of the slave associated with the exchange For Read operations the range of Device IDs is 1 to 247 For Write operations the range of Device IDs is 0 to 247 If the MODBUS query should be broadcast to all slaves enter 0 as the Device ID Target Type Select the type of data to be exchanged MODBUS Coils 0x MODBUS Discrete Inputs 1x MODBUS Input R
88. iagnostic Status words through a control bit described in chapter 7 Target Type The CCM memory type These types can be mapped to any RX3i CPU memory type in the Reference Address field If PLC Access is configured as Disabled Target Type is read only For the local data exchanges Read Continuous Read Continuous Bit Control or Read Single Bit Control the only Diagnostic Status can be chosen If PLC Access is configured as Read Only or Read Write Target Type can be Register Table Input Table or Output Table If PLC Access is configured as Write Only Target Type can be Input Table Bit Set Input Table Bit Clear Output Table Bit Set or Output Table Bit Clear Target Address Enter a value from 1 to 65535 This is the offset within the Target Type memory for the data to be read written Reference Address Specify the RX3i CPU memory type and starting address for the data to be read or written in the Data Exchange To select a memory type and starting address double click on the Ref Address field or right click and select Data Entry Tool Reference Address Fa oof Select a a starting address re Al Available Fil ow Limit 1 High Limit 64 Al00064 memory type End N Select a Available references Cancel Help 3 22 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Reference Length Specify the length of the memory area selected above in bits or
89. ified in the master s query If anew exchange is configured the PLC Access mode must be Read Write The Target Type must Registers 4x The configured Reference Address and Reference Length specify the CPU location of the data to be written The module writes the received data to the RX3i CPU then immediately replies to the MODBUS Master using a normal response as shown above GFK 2460A Chapter 5 MODBUS Communications 5 21 Report Slave ID MODBUS Function 17 A master can directa MODBUS Report Slave ID message to a specified slave to find the device type of the slave For an RX3i Serial Communications Module this function is only used in slave mode Master Query Slave i Device Function Byte Device Slave Run Normal Address Code Gount Type Light Data Error Check Response 17 RX3i Serial Communications Module Port in MODBUS Master Mode Not supported by a port configured for MODBUS Master mode Error Check RX3i Serial Communications Module Port in MODBUS Slave Mode No exchange configuration is needed The Serial Communications module automatically returns the Normal Response shown above The slave run light field is one byte in length This field indicates the state of the backplane Run line The slave response contains the following data Response Data Model 0 Slave Address 1 Function Number 17 decimal or 0x11 hex 2 5 data count 3 Major Revision Code eg
90. ime out will occur causing the communication to be aborted For an RX3i Serial Communications Module timeouts are the sum of the base value shown below plus the configured Timeout mS plus the configured Turnaround Delay of 0 to 65 535 milliseconds If the sum of the base timeout and the configured turnaround delay are greater than 65 535 OxFFFF 65 535 is used Setting the Timeout parameter to 0 does not disable timeouts for the CCM Slave Condition Base Timeout in mSec Wait on ACK NAK following ENQ 800 Wait on start of header following ACK of ENQ 800 Wait on header to finish 670 7 10 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A GFK 2460A A Acknowledge Current Error 4 11 Acknowledging Errors 4 14 B Baud Rates 1 2 Bit Control 3 11 C Cancel Pending Operation 4 12 Catalog Numbers 1 2 CCM Commands 7 3 CCM Memory Types 7 4 CCM Protocol 7 2 CCM Slave Communications 1 10 CCM Slave Operations 7 5 Checksum 3 4 Clear All Errors 4 11 4 14 COMMREGQs 1 6 Communications Standards 1 4 Configuration ID 3 4 3 9 3 14 3 19 CPU Stopped 4 2 CTS 3 14 3 19 Current specifications 1 3 D Data Bits 1 3 3 8 3 13 3 18 Data Rate 3 8 3 13 3 18 Data Rates 1 2 Delimiters 3 6 Diagnostics Data for CCM Slave Ports 7 8 Diagnostics Return Query Data 5 19 Dial or Hang Up a Modem 6 7 DO I O and Suspend I O 4 15 Documentation 1 1 Drop Delay 3 3 3 8 3 14
91. ion writes a specified number meho arca as conhoured Multiple meno of bits from Master to l Input Table y g p ry areas and types can be configured Write to Target from Source Output 6113 Table This function writes a specified number of bits from Master to Q Output Table GFK 2460A Chapter 7 CCM Communications 7 3 CCM Memory Types RX3i Serial Communications modules permit the CCM Master to perform the following read or write operations By default CCM Memory Types 1 3 and 13 18 are set up in the Serial Communications Module to access the conventional CCM Memory Types However the CCM Master can also access other memory types as described in chapter 3 CCM Description Memory Type in RX3i Slave Read MemoryType accessed by CCM CPU Register Table Defaults to R Register Table yes CPU Input Table Defaults to l Input Table yes s vs CPU Output Table Defaults to Q Output Table CCM Scratchpad CCM Scratchpad in module Y CCM Diagnostic Status CCM Diagnostic Status Words Words Defaults to I Input Table yes Defaults to Q Output Table yes Defaults to l Input Table applicable Defaults to Q Output Table yes can be configured in Serial Communications Module to access any RX3i CPU memory type R AI WAQ AW M Q T l yes yes yes es yes These types are stored internally in the RX3i Serial Communications module they are not mapped to PL
92. ith the LSB of the first byte The number of points is based on the configured reference length As soon as the module receives the data from the CPU it directs the query to the device address configured Station Address of the slave The starting point number configured as the Target Address can be any value less than the highest output point number available in the slave The sum of the starting point number and the number of points value must be less than or equal to the highest output point number available in the slave If the number of points is not a multiple of 8 the last data byte contains zeros in its higher order bits RX3i Serial Communications Module Port in MODBUS Slave Mode Using the default Data Exchanges the Serial Communications module automatically writes to the CPU Q discrete outputs The starting reference address and length are specified in the master s query If anew exchangeis configured the PLC Access mode must be Read Write The Target Type must Coils Ox The configured Reference Address and Reference Length specify the CPU location of the data to be written The module writes the received data to the CPU then immediately replies to the MODBUS Master using a normal response as shown above 5 20 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Preset Write Multiple Registers MODBUS Function 16 The master can issue a MODBUS Preset Write Multiple Registers mess
93. lding Regs 4x The Target Address is the offset from the start of the Master s Holding Registers table The configured Reference Address and Reference Length specify the CPU location of the data available to be read The module receives the requested data from the CPU then immediately sends it to the MODBUS Master using a Normal Response as shown above 5 14 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Read Input Registers Read Analog Inputs MODBUS Function 04 The master can direct a MODBUS Read Registers message to a specified slave to read up to 254 bytes 127 registers of the slave s analog inputs input registers 3x table The query and normal response formats are Device Function hi Master Starting Number of Error Check Query Register No Registers Slave Device Function Normal Address Error Check Response RX3i Serial Communications Module Port in MODBUS Master Mode An RX3i Serial Communications Module automatically forms a Read Registers query function code 04 from a Read exchange that has a Target Type of Input Registers 3x The module directs the query to the device address configured Station Address of the slave The starting register configured Target Address can be any value less than the highest register number available in the slave The number of registers configured Reference Length specifies the number of registers requested The sum of the starting r
94. ll be cleared continuously on the module until it is cleared to 0 If this bit is set to 0 CCM errors are accumulated in the module and could still be cleared by the CCM Master using a Write command to the Diagnostic Status Words GFK 2460A Chapter 4 Port Status and Control Data 4 13 Error Status Handling The module automatically returns the error status of an exchange in the Port Status input data The Error Status field contains the exchange status The Error Status Exchange Number contains the exchange number For MODBUS Master or Slave protocol this bit corresponds to the exchange number where the error occurred For Serial I O protocol bit 1 is set if there is a receive error Bit 2 is set if there is a transmit error To retrieve the status of a specific exchange specify the exchange number in the Port Exchange Error Selector field output bits 73 80 and clear the Acknowledge Current Error bit output bit 65 to 0 The module responds by setting the Error Status Exchange Number field input bits 193 200 to match the selected exchange number If there is no current error for the exchange the exchange number is returned in the Error Status Exchange Number inputs 193 200 and the Error Status value inputs 201 208 is 0 If the Port Exchange Error Selector value is set to 0 the module returns the error status and exchange number of the most recently completed exchange If an error has occurred the module also sets the corresponding
95. lt Data Exchanges the module automatically requests from the CPU an area of the R reference table The starting reference address and length are specified in the master s query If anew exchange is configured the PLC Access mode must be Read Write The Target Type must be Holding Regs 4x The Target Address is the offset from the start of the Master s Holding Registers table The configured Reference Address and Reference Length specify the CPU location of the data to be written When the module receives a query with function code 23 it first performs the write operation to the CPU registers It then performs the read from CPU registers After completing both actions the module replies to the MODBUS Master using a normal response as shown above 5 24 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Chapter Serial I O Communications 6 This chapter describes the Serial I O feature of RX3i Serial Communications modules Serial I O communications can be used to exchange up to 2K bytes of data with an individual serial device such as a modem that is connected to one of the module s ports Serial I O Communications for RX3i Serial Communications Modules Serial I O Features of Serial Communications Modules Local Serial I O Operations Initializing Resetting the Port Managing Hardware Flow Control for RS 232 Communications Reading Serial I O Data Reading the Port Status Flushing the Input Buffer Re
96. monitored by the receiver LRC checking is used to detect errors in an entire block The sending device inserts the LRC at the end of the header block and each block of data text The receiving device generates its own block check character based on the incoming data and compares it to the transmitted GFK 2460A Chapter 7 CCM Communications 7 9 LRC to detect errors This is handled automatically by the Serial Communications Modules if set up in the configuration Transmission Timing Errors Timing problems between transmitter and receiver can produce transmission errors such as overrun framing and time out errors Overrun An Overrun error is reported if timing problems between the transmitter and receiver cause characters to be sent faster than the receiver can handle them If that happens the previous character is overwritten and an error is indicated Framing Errors A Framing error is reported if the receiver mistakes a logic 0 data bit or a noise burst for a start bit The error is detected because the receiver knows which bit after the start bit must be a logic 1 stop bit If the start bit is really a data bit and the expected stop bit is not the stop bit but a start or data bit the framing error will be reported Timeout Errors Time outs are used to ensure that a good link exists between devices during a communication When a source device initiates a communication the target must respond within a certain amount of time or a t
97. n Seting vivir cc ie ate el Wi a vite ae a end tenis 3 13 iii Contents Chapter 4 Chapter 5 Automatic MODBUS Slave Exchanges c cccccccceeesseeeeeseieeeeeenieeeeeenteeeeenaeeeeeaas 3 15 Customizing MODBUS Slave Exchanges ccccccecceeeeeeeeeeeeeseeeeeeeseeneeeeeeeaees 3 15 Setting Up MODBUS Slave Data Exchanges 00 cccccceeeeeeeeeeeeeeeeeneeeeeeeaeeeeeeeaees 3 16 Configuring a Port for CCM Slave Protocol cccecceeeeseeeeeeeeneeeeeeneeeeeeneeeeeeneeeeeeaes 3 18 Serial Port SENINI Senie a ae ieee eat ee 3 18 Setting Up CCM Slave Data Exchanges 00 cccceceeseeeeeeeeeeeeeneeeeeenaeeeeeeneeeeeeaaes 3 20 Port Status and Control Data cccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeneeeeeees 4 1 Transfer of Status and Control Data ccccecccccceeeeeeeeceeceeeeeeeeeceaeeeeeeeeeteseneaeeeeeeeeeteees 4 2 Port Status Input Data sci cecsctectede ca tags eens eee ai e dads peak edd tages saga eae tae deh peak ees ages 4 3 Input Data Definitions 2 2 0 cecececeeeeececeeeeececeaeceeeeeeeeeesecaaeaeeeeeeesecscaeeeeeeeeeeeeseaeess 4 5 Port Control Output Data mas n en hes ete eta ee ieee 4 9 Output Data Definition Sat osre aes arte ural aes 4 10 Error Status Handling 0200 Lone cet a nate Lite he diene hadi 4 14 Using DO I O and Suspend VO sneanesi iiien iiad 4 15 DO I O Function Block Format ccccceeeeeeeeceeceeeeeeeseceaeaeeeeeeeeeeeneieeeeeeeeneneneees 4 15 MODBUS Communi
98. n program is responsible for supplying appropriate content for these four bytes in the CPU See chapter 4 for information about Port Control Output Data A Quick Read Enquiry starts with the ASCII character Q as its first byte O Master QZ Su aa Slave E N Block ETB LRC After receiving a Quick Read Enquiry the module immediately sends the 4 bytes of requested data from its internal memory The Slave response ends the communication 7 6 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Scratchpad Data Read only Scratchpad memory in the Serial Communications Module can be read by the CCM Master It is not accessible from the application program in the local CPU Any element within the 256 byte range may be read If the read request extends beyond the length of the scratchpad memory the module replies with an NAK The information within this memory is limited to a few parameters see table Valid Target Memory address range is 0 255 Scratchpad Address Field Identifier Definition Bits Byte Offset 0x00 Outputs Enabled Status 1 Outputs enabled 0 Outputs disabled 0x01 0x0D Reserved Always 0 Ox0E CMM Firmware Revision Major Ox0F CMM Firmware Revision Minor 0x10 0x15 Reserved Always 0 0x16 CCM CPU ID Number Slave 1 90 Decimal 0x17 0xFF Reserved Always 0 GFK 2460A Chapter 7 CCM Communications 7 7 Diagnostics Data for CCM Slave Ports The RX3i Communic
99. n screen read data flows from the target memory to the configured reference address Write data flows from the configured reference address to the target memory Settings Port1 Port2 Port3 Port 4 PortData ModbusMaster 1 PortData_ModbusMaster 2 PortData_ ModbusMaster 4 Power Consumption Data Exchange Number pe LRetebddress Ref Length Data Exchange Number 1 Data Exchange Number 2 Data Exchange Number 3 Data Exchange Number 4 Data Exchange Number 5 Data Exchange Number 6 Data Exchange Number 7 Data Exchange Number 8 Data Exchange Number 9 Data Exchange Number 10 Disabled Operation This parameter sets up how the MODBUS Master function will be performed The default for each exchange is Disabled Options are described below Read Continuous This type of exchange repeatedly reads the specified data from the target slave and places it into the assigned CPU reference addresses The CPU does not control this exchange It only stops when PLC outputs are disabled if the Outputs Disabled parameter on the Port tab is set to disable continuous exchanges when outputs are disabled Read Continuous Bit Control This type of exchange must be started by setting a bit in the CPU see chapter 4 for details The module then periodically reads the specified data from the slave until commanded to stop by clearing the same bit 3 10 PACSystems RX3i Serial Communications Modules Marc
100. nfigured Flow Control for RS232 only Default is none If Hardware Control is selected RTS and CTS will be used to control serial transmission flow and the module will be able to control the flow of data without losing any data bytes See chapter 6 for more information about managing Hardware Flow Control for RS 232 communications GFK 2460A Chapter 3 Configuration 3 3 Port Config ID Setting User Config ID Default is 1 range is 0 to 255 Use of a configuration ID is optional If a User Config ID is configured the module returns it to the CPU in each sweep of its Port Status data see chapter 4 Port Status and Control Data This feature might be used in an application where the same application logic is used with different configurations Serial I O Port Data If the protocol selected for a port is Serial I O configure the following parameters on the corresponding PortData_Serial I O tab Settings Port1 Pot 2 PortData_SeriallO 1 PortData_ ModbusSlave 2 j Parameters Values Serial 1 0 Read Configuratio _ Baad Cond Govan Read Serial 1 0 Memory Area Hi v Serial 1 0 write Configuration white CNY OSIN Write Serial 1 0 Memory Area 2AQ0 Checksum Configuration Validate Receive Checksum the default is No Receive Checksum If Validate Checksum is configured the module will automatically calculate a checksum on the data If the calculated checksum does not match the checksum at the end
101. nsmission mode The entire message is transmitted as a continuous stream of characters Between characters the line is held in the 1 state In RTU transmission mode gaps of silence are used to frame a message Because message frames must be separated by the intervals of silence MODBUS RTU is not recommended for use with modems which can compress or change the gaps between frames and interfere with message timing 1 8 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Introduction to Serial I O Communications Each port on an RX3i Serial Communications module can be set up for Serial I O protocol In Serial I O mode the port can exchange up to 2K bytes of data with an individual serial device such as a modem RX3i Serial Communications modules support the same Serial I O protocol features as the RX3i CPU Chapter 6 Serial I O Communications compares the Serial I O functions implemented using COMMREQs in an RX3i CPU with the same functions for an RX3i Serial Communications module The basic setup for read and write operations is done in the port configuration The port can be configured to read A data string of variable length up to a specified termination character A predetermined length of data When the specified number of bytes have been read the read operation stops A changeable length of data with the length supplied by the application in the port s output data When the specified number of
102. ocks except the last have 256 data bytes The Slave returns an ACK response after successfully receiving each individual data block The Serial Communications Module buffers the incoming data After successfully receiving all of the data blocks the Serial Communications Module transfers all of the data to the RX3i CPU in a single backplane communication The transfer of data is generally completed within 4 16mS However if the module is running processor intensive protocols on the other ports it may take longer The Serial Communications Module Slave then responds to the Master with an ACK character Because it first must transfer the data to the CPU the module takes longer to send ACK NAK for the last block than the preceding data blocks The Master responds with an End of Transmission character and the transaction is completed If the Serial Communications Module is not able to successfully transfer all of the data to the RX3i CPU the Slave port sends an EOT character instead of ACK after the last data block then goes to an idle state If the CCM Master receives an EOT instead of an ACK after a Write Request it should interpret the EOT as an indication that the write to the RX3i CPU did not occur GFK 2460A Chapter 7 CCM Communications 7 5 Normal Read Request from the CCM Master The Master can read up to 2K bytes of data from the RX3i CPU The Read Request starts start with a Normal N Enquiry which has the ASCII character N as its
103. of the received data the module will not pass the data to the CPU The checksum byte s are not sent with the data to the CPU if a checksum is calculated Append Transmit Checksum the default is No Transmit Checksum If the message should have a transmit checksum select Append Transmit Checksum to End of Message and specify the checksum type below Checksum Type The default is CRC16 The module will calculate a 16 bit Cyclic Redundancy Check across all data not including any end delimiters If BCC is selected the module will calculate a Block Check Character by doing an XOR of all data bytes 3 4 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Serial I O Read Configuration Read Control Operation The default is Receiving Disabled The other choices are Read Delimiter Byte Count Receiving Disabled prevents Serial I O read operations through the port If Receiving Disabled is selected a receive transaction will only read data bytes that are already in the port s internal Receive Buffer up to 2KB The number of bytes actually read will be indicated in the byte 24 bits 177 192 of the port s input status data Serial 1 0 Read Configuration Bead Conny Operati Receiving Disabled Read Serial 1 0 Memory Area Al00001 Read Delimiter if Read Delimiter is selected the data in the port s Input Buffer will be searched for the first occurrence of the configured Read End Delimite
104. ol Data Length Port 2 Status Data Port 2 Status Data Length Pott2ControlData 0 Port 2 Control Data Length 1 eneral Settings 0 Scan Set NIN ie The application logic monitors the status data for each port in the input references and sends commands to the port in the output references Those commands control the port s communications which result in the communications data described below While the CPU is stopped it does not read Port Status input data from the module When the CPU goes back into Run mode it starts reading the Status data again Serial Communications Data Serial communications data is exchanged separately and stored separately from the Port Status and Port Control Data Transfer of this data to and from the RX3i CPU is controlled by the module and is not synchronized with the I O Scan When the CPU is stopped or outputs are disabled the module continues exchanging serial communications data with the CPU Communications data uses another set of CPU reference addresses that are assigned during port configuration as shown below for a port in MODBUS Master mode Settings Port 1 Port 2 PortData_ModbusMaster 2 PortData_ ModbusSlave 1 Power Consumption Data Exchange Number Slave Address Target Address Ref Address Ref Length Data Exchange Number 1 R Data Exchange Number 2 D Data Exchange Number 3 D Data Exchange Number 4 D GFK 2460A Chapter 1 Introduction 1 7
105. ommunications ccccccceceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeaeeees 6 1 Serial I O Communications for RX3i Serial Communications Modules 000 6 2 Serial I O Features of Serial Communications Modules ccccceeeeseeeeeeeeees 6 2 Local Serial I O Operations cccccccccccecceceeeeeeeeecaeceeeeeeeseeeacaececeeeeesesacnaeceeeeeeeeeesnnaeees 6 3 Initializing Resetting the Port 2 0 0 e cece eeeeneeeeeenneeeeesaeeeeesnaeeeeeesaeeeeetaeeeeeeaaes 6 3 Managing Hardware Flow Control for RS 232 Communications eeeeeeee 6 3 Reading Serial VO Data cesia teen teeter eee tiie ee ee AREE sees ee a EEA AARE T aA 6 4 Reading the Port Status erarecon ati aias A aE A A AE LSAT EAR 6 4 Flushing the Input Buffer aerer een a aa aar 6 4 Reading Input Dala eiri ieaie EAA E EAA E EEEE 6 5 Writing Serial VO D taesicnariiieie i ai eniai tea caved Aiai i data ia 6 6 Dialing a Modem cierran uiie A Aa AE A SENAR 6 7 Chapter 7 CCM CommunicationS sssssssensunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn nnmnnn 7 1 COM Overview sanii a aa a aa deen da een a E aa ede aaa eaten 7 2 CCM Commands for RX3i Serial Communications Modules csccseeceeeeeeeeeeees 7 3 CCM Memory Types nis ness tanta ida we Atak G 7 4 CCM Slave Operations for the Serial Communications Module ccceseeeeeeeeeees 7 5 Write Request from the CCM Master cccceeeeeeeeceeceeeeeeesecen
106. on 3 23 3 24 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Chapter Port Status and Control Data 4 This chapter describes status control diagnostics and communications data for PACSystems RX3i Serial Communications modules It also explains how the DO I O and Suspend I O functions can be used with these modules Transfer of Status and Control Data Port Status Input Data Port Control Output Data Error Status Handling Using DO I O and Suspend I O Module Status and Control data does not include the serial communications data that is exchanged between the module and one or more serial devices That data uses a different set of assigned CPU references and is written to or read from the CPU outside of the CPU s normal I O Scan Because each protocol handles serial communications data differently serial communications data is covered in the chapters of this manual that describe the individual port protocols GFK 2460A 4 1 Transfer of Status and Control Data Module configuration reserves CPU memory for the module s Port Status and Control data Each port s status and control data references are configured separately lengths are fixed Data Type Total Data Length Memory Type Port Status Data CMMO02 448 bits l M T or discrete I O 224 bits per port CMMO004 896 bits variables Port Control Data CMMO002 256 bits Q M T or discrete I O 128 bits per port CMM004
107. ons Modules March 2007 GFK 2460A Introduction to Installing Serial Communications Modules Up to six RX3i Serial Communications modules can be installed in the PACSystems Universal Backplane Modules are installed following the general installation instructions in the PACSystems RX3i System Manual GFK 2314 Chapter 2 of this manual Installation and Wiring describes the module LEDs and communications ports and gives port pin assignments Note that RX3i Serial Communications modules require custom cables for MODBUS communications their port pin assignments do not match the MODBUS specification RX3i Serial Communications modules can be connected to one serial device for either RS 232 or RS 422 485 communications Connections to multiple devices require RS 422 or RS 485 communications Each port is easily set up for either RS 232 or RS 485 communications in the module configuration MODBUS Multidrop RS 485 For multidrop MODBUS connections in an RS 485 system either two wire or four wire Atleast 32 devices can be connected to an RS 485 network without a repeater Repeaters can be used if more devices are required An RS 485 MODBUS serial line without a repeater has one trunk cable Devices can be either connected directly or using short branch cables up to 20 meters In multidrop mode MODBUS slave devices must all use RS 485 compatible serial ports so that their transmitters are disabled except when transmitting Although
108. orced only once Master Query Slave Normal ae Error Check Response umber RX3i Serial Communications Module Port in MODBUS Master Mode This function is not available for an RX3i Serial Communications module port in MODBUS Master mode RX3i Serial Communications Module Port in MODBUS Slave Mode Using the default Data Exchanges the Serial Communications module automatically writes to the CPU Q reference table The starting reference address and length are specified in the master s query A new exchange can be configured that maps some amount of Q memory to coils The PLC Access mode must be Read Write The Target Type must Coils 0x The Target Address is the offset from the start of the Master s Input Registers table The configured Reference Address and Reference Length specify the CPU location of the coils available to be forced by the master After writing the received data to the CPU the module replies to the MODBUS Master using a normal response as shown above The normal response to a force single output query is identical to the query 5 16 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Preset Write Single Register MODBUS Function 06 The master can issue a MODBUS Preset Write Single Register message to one slave or to all slaves to set a single register in the registers holding registers 4x table The register is written automatically Device Function F Master dick
109. orresponding control bits For all of these exchange types the module automatically provides success or error status for the exchange in the Port Status input data as described earlier in this chapter Read Periodic Bit Control This type of exchange continuously reads MODBUS data from the specified slave for as long as the corresponding Exchange Control Bit is set to a 1 Read Single Bit Control This type of exchange reads data from the specified slave once when the corresponding Exchange Control Bit transitions to 1 To be sure the exchange is not missed or unintentionally repeated the Control Bit should remain set to 1 until the module has completed the exchange and notified the CPU by setting the corresponding input Exchange Success Report or Exchange Error Report bits to 1 This type of exchange is controlled by a toggle bit Note that if Input Status bit 131 Control Bit Ready transitions to 0 all Exchange Control outputs bits must be reset to 0 to guarantee that the exchange is not processed If the exchange should be processed after the control bits are ready again Input Status bit 131 goes to 1 set the Exchange Control bit to 1 For example if the Input Status bit for Exchange Number 4 is currently 0 to execute the exchange on the next output scan the application logic should set the control bit to 1 The exchange is complete when the Input Status bit also becomes 1 To execute exchange 4 a second time set the control bit to 0
110. ost up to date release information for these two modules PACSystems RX3i System Manual GFK 2314 This manual details system and module installation procedures and includes descriptions and specifications of PACSystems RX3i I O and option modules PACSystems RX3i user manuals module datasheets and other important product documents are available online at www gefanuc com They are also included in the nfolink for PLC documentation library on CDs catalog number IC690CDRO02 RX3i Serial Communications modules function as part of a larger control system Additional documentation may be needed to complete the system installation and configuration GFK 2460A 1 1 Introduction to PACSystems RX3i Serial Communications Modules PACSystems RX3i Serial Communications modules expand the serial communications capabilities of an RX3i system MODULE OK PORT FAULT Serial Communications module IC695CMMO02 provides two independent isolated serial ports Serial Communications module IC695CMMO04 illustrated at right provides four independent isolated serial ports Up to six Serial Communications modules can be located in the main PACSystems RX3i backplane Each port can be configured for MODBUS Master MODBUS Slave Serial I O protocol In addition for modules that are version 1 02 or later each port can be configured for CCM Slave protocol Additional module features include Port to port isolation and port to backplane isolation RS 2
111. ot support the faster data rates that are available on RX3i Serial Communications modules Data rates of 1200 baud through 19 2K baud should be compatible with all modules Data bits CCM protocol always uses eight data bits and one stop bit Parity None Odd Even Default is odd Stop Bits Default is 1 CCM protocol always uses eight data bits and one stop bit Timeout For CCM there are eight predefined timeouts see chapter 7 conditions The overall timeout period is the sum of these eight timeouts plus the configured Turn Around Delay plus the Timeout in milliseconds configured here If the Timeout value for CCM protocol is set to 0 timeouts are NOT disabled Port Type RS232 RS485 2 wire or RS485 4 wire CCM Hardware Modules use the RS 232 or RS 422 communication standards An RX3i Communications Module can be configured for RS 232 or RS 485 RS 485 4 wire mode is backward compatible to RS 422 3 18 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A allowing the RX3i Communications Module to be used on CCM RS 422 networks Refer to the hardware specification for more information Tx RTS Drop Delay bits defaults to 0 Range 0 to 15 bit times For RS485 4 wire only This is the time from the end of the last transmitted character to the time when the transmitter is turned off dropped For RS 232 with Hardware Flow Control enabled this is the time from the end of the last transmitted character to the
112. ponse to a preset single register query is identical to the query GFK 2460A Chapter 5 MODBUS Communications 5 17 Read Exception Status MODBUS Function 07 The master can direct a Read Exception Status MODBUS message to a specified slave to read the first eight output points Device Function l Master Error Check Query l Slave Device Function J Normal Error Check Response RX3i Serial Communications Module Port in MODBUS Master Mode The Read Exception Status function function code 07 is not explicitly supported by RX3i Serial Communications modules RX3i Serial Communications Module Port in MODBUS Master mode Configuring a Read exchange with a length of Target Type of Coils Ox and a Target Address of 1 will accomplish the same function The module automatically forms a Read Coils query from the configured exchange and directs it to the slave The data field of the normal response is one byte in length It contains the states of output points one through eight The output states are packed in order of number with output point one s state in the least significant bit and output point eight s state in the most significant bit As soon as all of the data has been received the module automatically writes it to the configured CPU Reference Address area RX3i Serial Communications Module Port in MODBUS Slave Mode Using the default Data Exchanges the Serial Communications module automatically requests the first 8
113. port is reset by the application setting Port Command bit 67 The module receives a new configuration For Serial I O only the first two Exchange Error Report bits are used If bit 65 1 a Serial I O receive error has occurred If bit 66 1 a transmit error has occurred Port Status Input Bits 129 144 Bytes 17 18 These two bytes provide information about the status of the port for all protocols Bit 129 indicates whether or not the port is ready for communications Bit 130 indicates whether or not the port is currently being configured Bit 131 indicates whether or not the exchange Control bits are ready to control exchanges Bits 132 to 136 are reserved Byte 18 bits 137 144 contains the Configuration ID that was configured for the port If the application includes multiple configurations this bit can be used to check which configuration is being used for the port 4 6 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Protocol Status Input Bits 145 192 Bytes 19 24 For Serial I O these bits provide the following information Not used for MODBUS CTS Status Bit 145 is used for RS 232 communication when the port s Flow Control parameter has been configured for Hardware Control RTS CTS Before transmitting the CPU should set output bit 84 Activate RTS in the port s Port Control Data to 1 to force RTS on the port The CPU should then check input bit 145 CTS active When this bit is 1 th
114. r point to point connections up to about 25 meters in length It is not suitable for longer lines or multidrop connections The RS 232 specification recommends limiting the data rate to 19 200 bits per second bps or less but rates up 115 200 bps are sometimes used with short cables typically about 2 meters RS 485 In RS 485 mode line drivers in the data circuits are required to switch to a high impedance state except when transmitting and the control and status circuits are rarely connected through the cable in multidrop applications Consequently multiple data line drivers can be connected in parallel to each data circuit The port firmware guarantees only one port at a time will attempt to transmit on each circuit RS 485 uses 120 ohm cable and terminating resistors Because transmitters are not always connected to the line terminating resistors must be used at both ends of each circuit Some RS 485 serial devices require pull up and pull down resistors to polarize bias receive data circuits to the mark state when all transmitters are in the high impedance state The ports on RX3i Serial Communications modules do not require pull up and pull down resistors In a multidrop network slave devices must all use RS 485 compatible serial ports so that their transmitters are disabled except when transmitting The master may use either RS 422 or RS 485 because it is the only transmitter on that pair 1 4 PACSystems RX3i Serial Communicati
115. r terminating character s When the Read End Delimiters are found the data is transferred to the CPU without the terminating characters If the terminating characters cannot be found the receive operation will be terminated after the timeout period has expired The module will set the Exchange Error Report bit bit 65 of the port s status data to 1 and byte 24 bits 177 192 of the port s input status data to 0 n Bood erin Operation he ead Serial 0 MemoyArea Al ead Seall O Data Lenn 0 Byte Count if Byte Count is selected a static or dynamic number of bytes will be read depending on the additional choices below Once the number of bytes selected is received the data is transferred to the CPU Serial 1 0 Read Configuratio Feat Sonny Gaerne Read Serial 1 0 Memory Area Read Serial 1 0 Data Length 0 FAIT EAD Sauce Static Read Length Read Serial I O Memory Area the CPU reference area for data read from the serial device Possible memory types are Al WAQ R M Q or l Read Serial I O Data Length the length in 8 bit increments or 16 bit words as appropriate for the CPU reference area that will be used for Serial I O read data The length must accommodate the largest amount of data that may be read in one transaction GFK 2460A Chapter 3 Configuration 3 5 Read Length Source If Read Control Operation is set to Byte Count and the length of the data will not always be the same
116. ransmit error CCM Slave Exchange number of the error in the Error Status field below 26 201 Error Status 208 General 0 no error 6 transmit timeout Errors 1 generic port error or module error 7 module failed to send to CPU 2 receive overflow 8 sent to CPU but failure response 3 parity error 9 not able to send to CPU module 4 framing error timed out 5 receive timeout MODBUS 20 unrecognized exception 29 through 35 reserved 21 illegal function 36 CRC error on response 22 illegal data address 37 unexpected slave address 23 illegal data value 38 unexpected function code 24 slave device failure 39 unexpected response length 25 acknowledge 40 exchange register type is bad 26 slave device busy 41 exchange register address is bad 27 negative acknowledge 42 returned query data does not match 28 memory parity error Serial I O 20 data requested exceeds 22 Data buffer overflow New data assigned memory discarded until characters have been 21 bad checksum Message removed from the buffer discarded 23 transmit command cancelled 24 receive command cancelled 25 data size exceeds 2k limit CCM Slave No additional error codes defined 27 209 Period Time 28 224 The time to execute all Master exchanges in milliseconds 0 for slave protocols 0 65535 for master protocols Exchange times above 65535mS appear as 65535mS 4 4 PACSystems RX3i Serial Communications Modules March 2007 G
117. red in each exchange When the module is started up it receives its configuration from the CPU The module processes each exchange in order from 1 to 64 An exchange is processed if it is enabled and the control operation indicates it is ready to be processed Processing the exchange consists of a single read or write operation with an externally connected slave For a read operation the module requests data from the specified slave When the module has received all of the requested data it writes the data to the configured reference addresses in CPU memory For a write operation the module reads CPU memory and sends the data it to one or more slave device s Upon completion of processing the exchange status information is set Once all enabled exchanges have been processed operation continues with exchange number 1 5 8 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A How the Module Handles a Write Request in Master Mode The module forms a standard MODBUS write request for each Write Continuous Write Continuous Bit Control or Write Single Bit Control exchange that has been set up in the port configuration At startup or after the application turns on or toggles the control bit associated with the exchange the module follows these steps 1 The module sends the appropriate write query via the MODBUS serial port 2 Fora directed write request the module then waits for a positive acknowledge response f
118. response formats are Device Function Startin Number of Master Address Code Point a oe Error Check Query 01 o i j Slave Device Function l Normal Address Error Check Response l RX3i Serial Communications Module Port in MODBUS Master Mode An RX3i Serial Communications module automatically forms a Read Coil Status query function code 01 from a Read exchange that has a Target Type of Coils Ox The module directs the query to the device address configured Station Address of the slave The starting point number configured exchange Target Address can be any value less than the highest output point number available in the slave The number of points configured exchange Reference Length specifies the number of output bits requested The sum of the starting point number value and the number of points value must be less than or equal to the highest output point number in the slave When all the data has been received from the MODBUS Slave the module automatically writes the data highlighted above to the configured CPU Reference Address area and updates the exchange status information RX3i Serial Communications Module Port in MODBUS Slave Mode Using the default Data Exchanges the module automatically requests from the CPU an area of the Q reference table The starting reference address and length are specified in the master s query Ifa new exchange is configured the PLC Access mode may be Read Onl
119. rial Communications Manual GFK 0582D For Series 90 PCM applications refer to the Series 90 Programmable Coprocessor Module Manual GFK 0255K For Series Six CCM applications refer to the Series Six PLC CCM Communications Manual GFK 25386A These documents are available at the GE Fanuc website and on the Infolink CD documentation library 7 2 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A CCM Commands for RX3i Serial Communications Modules As a CCM Slave an RX3i Serial Communications Module supports the CCM Master commands listed below The Command Numbers listed in the left column are used in the Master s application program to identify the command to be executed they are not part of the CCM communication itself and they are not relevant to the RX3i Serial Communications Module Master Command Number CCM Command number not supported This Set Q Response Local command which function is automatically handled in the 6001 passes four bytes of data from the CPU y Command Description Implementation for for CCM Masters RX3i Serial Communications Modules to the CCM interface module s Port Control Output data as described in chapter 4 CCM Command number not supported This eo02 ilies CCM Status Words Local function is handled with the Clear CCM Errors command Control bit Read CCM Diagnostic Status Words GCM command number not supported TRIG Local commana which reade CCM function is handle
120. rned by the module in the input data 11 16 81 128 Output Commands to the Module MODBUS Master Slave this data not used Serial I O Bit 81 1 cancel pending receive operation Bit 82 1 cancel pending transmit operation Bit 83 1 flush input buffer Bit 84 1 activate RTS RS232 only with HW Control disabled Bits 85 96 not used Bits 97 112 word Number of characters to read when Dynamic Read is configured Bits 113 128 word Number of characters to write when Dynamic Write is configured GFK 2460A Chapter 4 Port Status and Control Data 4 9 Byte Bit Description CCM Slave Bytes 11 14 Used for data to be sent when module receives Quick Response Q sequence from Master Byte 15 Bit 0 the Clear CCM Errors Control bit Used to select automatic clearing of CCM Diagnostic Status Words 0 CCM errors will be accumulated 1 CCM errors will be cleared each time a CCM port is processed Byte 15 bits 1 15 and Byte 16 not used Output Data Definitions Exchange Control Output Bits 1 64 For MODBUS Master not used for MODBUS Slave The CPU must set these bits to start execution of MODBUS Master exchanges that have been configured as Read Periodic Bit Control Read Single Bit Control Write Periodic Bit Control and Write Single Bit Control These bits do NOT control exchanges configured as Read Periodic or Write Periodic Those exchanges are executed regardless of the state of the c
121. rom the slave 3 The module will make up to 3 attempts to send the message before declaring failure if a response is not received 4 The module updates the exchange completion status How the Module Handles a Read Request in Master Mode The module forms a standard MODBUS read request for each Read Continuous Read Continuous Bit Control or Read Single Bit Control exchange that has been set up in the port configuration At startup or after the application turns on the control bit associated with the exchange the module follows these steps 1 The module sends the read query via the MODBUS serial port 2 The module waits for positive acknowledge response 3 The module will make up to 3 attempts to send the message before declaring failure if a response is not received 4 After receiving data from the slave the module immediately sends the data to the CPU 5 The module updates the exchange completion status GFK 2460A Chapter 5 MODBUS Communications 5 9 MODBUS Master Diagnostics The module automatically tracks the status of each MODBUS Master exchange This data is not provided to the CPU automatically If the application will monitor this data the port configuration should include a Data Exchange with a Target Type of Diagnostic Status The Reference Length is always 18 words 288 bits the length of the status data Additional configuration setup includes selecting an Operation type for the Data Exchange It can be
122. s Error Check Query umber High Low Slave Device Function i Normal baen Error Check Response UmDSr High Low RX3i Serial Communications Module Port in MODBUS Master Mode An RX3i Serial Communications Module automatically forms a Preset Write Single Register query function code 06 from a Write exchange that has a Target Type of Holding Registers 4x and a length of 1 register The module directs the query to the device address configured Station Address of the slave The register number configured Target Address can be any register available in the slave The data field is two bytes in length The module supplies this data from the register value received from the CPU As soon as the module receives the data from the CPU it writes the query to the MODBUS Slave RX3i Serial Communications Module Port in MODBUS Slave Mode Using the default Data Exchanges the Serial Communications module automatically writes to the CPU R reference table The starting reference address and length are specified in the master s query If anew exchange is configured the PLC Access mode must be Read Write The Target Type must Holding Registers 4x The configured Reference Address and Reference Length specify the CPU location of the data available to be written to The module writes the received data to the CPU then immediately replies to the MODBUS Master using a normal response as shown above The normal res
123. s and Control Data cccccccececeeeeeeececeeeeeeeeeeeceaeaeeeeeeesecnaaeaeeeeeeeseescnieaeeeeeess 1 7 Serial Communications Data cccccccccseccececeeeeeeeececeaeceeeeeeesecceeaeeeeeeeeeeensacaneseees 1 7 Introduction to MODBUS Communications cccccceeeeecceceeeeeeeeeceeeeeeeeeesetsnnieaeeeeeess 1 8 Supported MODBUS Functions eccccecccceceeeeeeeeceeceeeeeeeseccaeceeeeeeeesessnnieaeeeeees 1 8 Supported Transmission Mode ccceececceceeeeeeeeeeeeeeeeeeeeesecenaeaeeeeeeeseesenieaeeeeees 1 8 Introduction to Serial I O Communications cccccccseeceececeeeeeeeeecaeaeeeeeeesessnnieaeeeeeess 1 9 Monitoring and Controlling Serial O Communications ceeeeeseteeeeeeteeeeeees 1 9 Introduction to CCM Slave Communications cceceeeecceceeeeeeeeeeceeeeeeeeteenieeeeeeeeteees 1 10 Installation and Wiring sssssssssssssnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn 2 1 Installation in Hazardous Locations cccceceeeecee cece ee eeeeceeeaeeeeeeeeeeeneaeaeeeeeeesetsnnieeeeeeeees 2 2 LEDS isis ded native cable oes iad a ed eat tk eee eee ee 2 3 SOT alli POMS aie oss teers tet ed iaven aoe dd a stan a a Dk adeesat a ae 2 4 POM PINCASSIQNMENUS oein aT laasahanthacpeestaeemnins eaeed aa deheeedapareteas 2 4 Termination eshte tae ee cede ces ees eats ect etna ss cae aye dea ney ace ei acy a a a ea ea aad 2 5 Point to Point Serial CONNECTIONS
124. select Dynamic Read Length When Dynamic Read Length is selected the application program must supply the read length in bits 97 112 of the Port Control output data it sends to the module each I O Scan If the data length to read will always be the same select Static Read Length Static Read Length If Read Control Operation is set to Byte Count and the length of data to be read using Serial I O Protocol will always be the same enter the number of bytes to be read The range is 0 to 2048 2K bytes which is the total amount of data in the buffer If the length is set to 0 the module will send the CPU all of the data in the port s input buffer Read End Delimiters f Read Control Operation is set to Read Delimiter configure the end delimiters using up to 4 ASCII characters separated by commas or spaces During operation the module will scan the incoming data for this combination of characters and will receive the data once the terminating characters are found The terminating characters may be any combination of individual characters a z A Z 0 9 or as hexadecimal characters For example 0x41 a b c aa 0x41 0x41 0x42 0x43 0x44 Because either commas or spaces can be used to separate characters when configuring the values if a comma is desired as a delimiter its ASCII hex code should be used When the hardware configuration is validated any non hexadecimal characters that have been entered in the configuration are automatically
125. sets all bits to 0 on startup For continuous exchanges Last exchange completed successfully one bit per exchange bit 1 exchange 1 to bit 64 exchange 64 MODBUS For single bit control exchanges Last exchange completed Master successfully when this matches the corresponding control bit one bit per exchange bit 1 exchange 1 to bit 64 exchange 64 0 Last Exchange Execution Failed or has yet to be executed MODBUS a Slave 1 Last exchange execution completed successfully one bit per exchange bit 1 exchange 1 to bit 64 exchange 64 Bit 1 indicates a new Serial I O receive has completed when this bit matches the corresponding control bit Serial I O Bit 2 indicates a new Serial I O transmit has completed when this bit matches the corresponding control bit Bits 2 64 are reserved If PLC Access is configured as Read Only Read Write or Write Only 0 Last Exchange Execution Failed or has yet to be executed 1 Last exchange execution completed successfully one bit per exchange bit 1 exchange 1 to bit 64 exchange 64 CCM Slave If PLC Access is configured as any other type For continuous exchanges Last exchange completed successfully one bit per exchange bit 1 exchange 1 to bit 64 exchange 64 For single bit control exchanges Last exchange completed successfully when this matches the corresponding control bit one bit per exchange bit 1 exchange 1 to bit 64 exchange 64 9 16 65 128 Exchange Error Report
126. some RS 422 devices disable outputs when not transmitting the RS 422 specification does not require it The master may use either RS 422 or RS 485 because it is the only transmitter on that pair f a multi port tap is used each branch has a maximum length of 40 meters divided by the number of branches fed by that tap Two wire devices can be connected to a four wire network and vice versa following the instructions in chapter 2 GFK 2460A Chapter 1 Introduction 1 5 Introduction to Serial Communications Module Configuration Chapter 3 Configuration describes the configurable parameters of PACSystems RX3i Serial Communications modules Configuration with Proficy Machine Edition software is an important part of setting up module communications because RX3i Serial Communications modules do not use COMMREQs for communications between the CPU and the module A module s configuration determines all of its communications capabilities from the basic setup of each port Settings Port 1 Port 2 PortData_Seriall0 1 Power Consumption Values Serial 1 0 Serial Port Settings j i 1 x RATS Drop Delay bits D Port Config ID Setting g User Config ID To the details of reading and writing data 724100001 rakai Seneive Qnack stan No Receive Checksum Feat fang Sawee Static Read Lenath For some slave protocols pre configured default data exchanges are provided that can
127. ss 0 Slaves do not respond to broadcast messages However the Master expects a delay so that the slaves can process the request This delay is called the Turnaround Delay The master goes into a Waiting Turnaround Delay state The Turnaround Delay must be long enough for any slave to be able to process the request and receive a new one Therefore the Turnaround Delay should be shorter than the Response Timeout Typically the response timeout is 1s to several seconds at 9800 bps and the turnaround delay is 100ms to 200ms All slaves that receive the broadcast message perform the requested function When a broadcast message is sent to all slaves they do not send responses Instead of waiting for a response the master instead waits a specified length of time for the slaves to process the request before the master sends another message Master Broadcast Message Slave Turn around Time Slaves No Response GFK 2460A Chapter 5 MODBUS Communications 5 3 MODBUS Message Formats Each MODBUS serial message consists of a sequence of message fields a Device Address a Function Code optional Data fields and an error check field The diagram below shows the basic format of aMODBUS message frame E E E MODBUS Frame on Serial Line oen gt Device Function Data Error Address Code optional Check B a ad Automatically Supplied by RX3i Serial Communications Module In MODBUS Master mode an RX3i Serial Communications module autom
128. ter 3 Configuration Chapter 4 Port Status and Control Data details the data that is automatically exchanged between the module and the RX3i CPU each I O Scan The application uses that automatic data transfer to control and monitor communications through each port This chapter describes MODBUS Master and MODBUS Slave operations for RX3i Serial Communications modules MODBUS Communications Overview Messages and Responses MODBUS Message Formats MODBUS Data Addressing MODBUS Communications for RX3i Serial Communications Modules Supported MODBUS Functions Supported Transmission Mode How MODBUS Functions are Implemented MODBUS Master Operation for RX3i Serial Communications Modules How the Module Handles a Write Request in Master Mode How the Module Handles a Read Request in Master Mode MODBUS Master Diagnostics MODBUS Slave Operation for RX3i Serial Communications Modules How the Module Handles a Read Request in Slave Mode How the Module Handles a Write Request in Slave Mode MODBUS Functions for RX3i Serial Communications Modules This section describes each MODBUS function that is supported by RX3i Serial Communications modules and explains how to implement the function for a Serial Communications module in master or slave mode GFK 2460A 5 1 MODBUS Communications Overview This section is a quick reference to MODBUS communications For a Serial Communications module port configured as a MODBUS
129. ter or peer to peer operation CCM Networks use the RS 232 RS 422 communication standards RS 422 is necessary for a multi drop Master Slave network Communication is asynchronous half duplex at speeds up to 115 2K baud As a CCM Slave an RX3i Serial Communications Module will respond to the CCM Master commands listed below The Command Numbers listed in the left column are used in the Master s application program to identify the command to be executed they are not part of the CCM communication itself and they are not relevant to the RX3i Serial Communications Module Master Command Command Description Number CCM Protocol defines additional commands that can be used by Masters or by other CCM devices However any CCM command that is not listed above cannot be processed by an RX3i Serial Communications module That includes Local CCM commands that might be sent in COMMREQs by the RX3i CPU The functions performed using Local CCM commands for other types of CCM modules are not used for RX3i Serial Communications Modules Implementation of CCM functions for an RX3i Serial Communications module is different from the implementation for other CCM devices Chapter 7 CCM Communications describes CCM for an RX3i Serial Communications module 1 10 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Chapter Installation and Wiring Z This chapter provides installation information for RX3i Serial Communications mo
130. the port The CPU should then check input bit 145 CTS active When that bit is 1 the port can safely transmit If CTS does not become active within 2 seconds the module returns a timeout error to the status location After the last transmit character is sent the CPU must set the RTS bit to 0 4 12 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Dynamic Read Length bytes 13 14 bits 97 112 word If the Read Control Operation parameter is set to Dynamic Read Length the CPU must specify the length of data in bytes to be read here Dynamic Write Length bytes 15 16 bits 113 128 word If the Write Length Source parameter is set to Dynamic Write Length the CPU must specify the length of data in bytes to be written here For CCM Slave bytes 11 through 14 of the Port Control Output data are used for CCM Quick Response data As described in chapter 7 the CCM Master can request four bytes of data directly from the Serial Communications Module using a Quick Read request The Serial Communications Module automatically receives this data from the RX3i CPU in its output data and stores it internally The RX3i application program is responsible for maintaining the content of these four bytes in the CPU The least significant bit of byte 15 of the Port Control Output data can be used to control whether or not the CCM Diagnostic Status Words will be cleared automatically If this bit is set to 1 CCM errors wi
131. to the module each I O Scan Static Write Length Default is 0 Range is 0 to 2048 2K bytes which is the maximum amount of data the write buffer can contain GFK 2460A Chapter 3 Configuration 3 7 Configuring a Port for MODBUS Master Protocol On the port tab set Protocol to MODBUS Master then configure the additional port parameters as described below Settings Port 1 Port 2 PortData_ModbusMaster 1 eee E Fata MODBUS Master m Serial Port Settings DataRate Databits Paty d Stopbits Timeout mS Fit Fyne Tx RATS Drop Delay bits Flow Control Port Config ID Setting User Config ID Serial Port Settings Data Rate Default 19 2k Baud Choices are 1200 2400 4800 9600 19 2k 38 4k 57 6k 115 2k Baud Data bits Always 8 for MODBUS Master Parity None Odd Even When parity ODD or EVEN the character length used by MODBUS Master is 10 bits one start bit 8 data bits one parity bit and one stop bit There is no parity bit when parity NONE and the character length is 9 bits The selection should match the parity used by other devices on the network Stop Bits Default is 1 Choices 1 2 If Parity is set to Odd Even the number of Stop Bits should be 1 If Parity is set to None the number of Stop Bits should be set to 2 The Stop Bits setting should be 1 stop bit for compatibility with GE Fanuc Automation MODBUS Slaves Timeout mS Range is 0 to 65535ms An error
132. ts are different than the standard MODBUS pin assignments If the port is configured for MODBUS master or slave operation custom cables are needed RJ 45 RS RS 485 422 RS 485 422 Pin 232 Half Duplex Full Duplex 8 COM GND GND 7 Termination 2 6 CTS R RxDO 5 COM GND GND 4 Termination 1 3 RxD R RxD1 2 TxD T R DO T TxDO 1 RTS T R D1 T TxD1 Note There is no shield or frame ground pin on this connector If the Serial Communications module is communicating with a Series 90 30 CPU363 or external PACSystems RX3i CPU the connections are RX3i Serial Module CPU363 RX3i T To RD B T To RD A R To SD B R To SD A 2 4 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Termination Termination is needed if the module is the first or last device on an RS 485 network even if there is only one other device on the network Termination can be provided using either an external resistor or the port s built in 120 Ohm termination If line termination other than 120 Ohms is required an appropriate external resistor must be supplied Termination using the built in 120 Ohm resistor can be done by either setting the appropriate RS 485 termination jumper as shown at the bottom of the page OR by installing shorting jumpers on the RS 485 cable connector that attaches to the serial port User Supplied Termination
133. umber 2 l Data Exchange Number 3 Default Data Exchanges 3 20 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Configuring Custom Data Exchanges If the Master should NOT be permitted to read or write part or all of R l or Q memory or if the Master should be permitted access to other memory areas the configuration can be customized on this tab Also by default the module will NOT automatically send its CCM Diagnostics Status data to the local RX3i CPU If that data should be provided to the CPU a new Data Exchange can be set up for that purpose as described in this section When customizing the CCM Slave Data Exchanges it helps to know how the Serial Communications Module will process the exchanges The module maintains an internal record of up to 64 of Data Exchange definitions When the module receives a CCM request from the Master the module scans the Data Exchanges from 1 to 64 The module compares the Target Type Starting Target Address and Reference Length parameters of the request against the configured Data Exchanges until a match is found If no match is found an error is returned to the requesting master If a match is found the requested exchange is carried out The first match found while scanning from exchange 1 to 64 is always used Data Exchange Parameters The following parameters can be defined for each Data Exchange type PLC Access PLC Access Read Write Disabl
134. uter Master Master Slave Slaves Multi Drop Network Point to Point Connection The Master may download data to the slave stations or upload data from the Slave stations Slave stations only respond to requests from the Master station and cannot initiate communications Masters cannot broadcast a message to all Slaves CCM Networks use the RS 232 RS 422 communication standards RS 422 485 is necessary for a multi drop Master Slave network Communication is asynchronous half duplex at speeds up to 115 2K baud To avoid data collisions on a multi drop network slaves only speak when spoken to A PACSystems Serial Communications Module port can be used as a CCM Slave only on either a point to point or multidrop link Other CCM compatible devices on the link may include Series 90 70 Communications Coprocessor Module IC697CMM7 11 Series 90 70 Programmable Coprocessor Module IC697PCM711 Series 90 30 Communications Coprocessor Module IC693CMM31 1 Series 90 30 Programmable Coprocessor Module IC693PCM300 301 or 311 CCM protocol is NOT available on Series 90 CPU serial ports CCM protocol was originally developed for Series Six Communications Control Modules CCMs such as IC600CB536 IC600CB537 and IC600BF948 Instructions for using CCM protocol on other modules are not included here For Series 90 CCM applications refer to the Series 90 PLC Se
135. ve attempts are canceled while this bit is set If this bit is set and then reset before the next Receive error code 24 is written and the next Receive operation will not be cancelled If this bit is set when a Receive is not ongoing the error code switches to 24 and no Receives can occur until this bit is reset Cancel Pending Transmit Operation Output Bit 82 Setting this bit to 1 stops a pending Serial I O transmission If this bit is set when a Transmit is ongoing the Transmit stops and the error code changes to 23 Subsequent Transmit attempts are cancelled while this bit is set If this bit is set and then reset before the next Transmit there is no effect If this bit is set and then reset before the next Transmit error code 23 is written and the next Transmit operation will not be cancelled If this bit is set when a Transmit is not ongoing the error code switches to 23 and no Transmits can occur until this bit is reset Flush Input Buffer Output Bit 83 Setting this bit to 1 clears the port s input buffer of all characters that have been received but not read by the CPU If a read buffer is pending at the same time a flush buffer operation is requested the read buffer operation will be executed first before clearing the contents of the buffer Activate RTS Output Bit 84 If the port is configured for RS232 operation and Flow Control is configured for HW Control RTS CTS the CPU should set output bit 84 to 1 to force RTS on
136. y or Read Write The Target Type must be Coils 0x The Target Address is the offset from the start of the Master s Coils table The configured Reference Address and Reference Length specify the CPU location of the data available to be read The module requests the data from the CPU After receiving the data the module immediately sends it to the MODBUS Master using a Normal Response as shown above 5 12 PACSystems RX3i Serial Communications Modules March 2007 GFK 2460A Read Input Status Read Input Table MODBUS Function 02 The master can direct a MODBUS Read Input Status message to a specified slave to read up to 254 bytes of data from the slave s discrete inputs 1x table The query and normal response formats are Device Function i i Master Starting Number of Error Check Query Point No Points Slave Device Function l Normal Address Error Check Response i RX3i Serial Communications Module Port in MODBUS Master Mode An RX3i Serial Communications module automatically forms a Read Input Status query function code 02 from a Read exchange that has a Target type of Discrete In 1x The module directs the query to the device address configured Station Address of the slave The starting point number configured Target Address can be any value less than the highest input point number available in the slave The number of points configured Reference Length specifies the number of input bits requested

PACSystems RX3i Serial Communications Manual, GFK

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