Chapter 6. Programming EGD Commands104 PACSystems* RX7i & RX3i TCP/IP Ethernet Communications User Manual GFK-2224Q6.8 Write EGD Exchange (4003)The Write EGD Exchange command can be used to write portions of a configured Ethernet Global Dataexchange in a remote producer node. EGD protocol prohibits writing to a consumed exchange. This commandidentifies the exchange to be written using its configured Producer ID and Exchange ID. It can then write thecontent of that data directly to the device memory. This command can be sent to PACSystems PLCs and toother EGD Class 2 devices. In a PACSystems PLC, writing an EGD exchange modifies the PLC reference memorylocations configured for transfer at the specified offset in the exchange. Thus current process data will beupdated, not the data that was transferred last in the exchange.Write EGD Exchange Command BlockWord Offset Value DescriptionWord 1 Length of command datablockAlways 19Word 2 0 Always 0 (no-wait mode request)Word 3 (See table on page 95) Memory type of COMMREQ Status WordWord 4 0-based 13 Offset of COMMREQ Status WordWord 5 0 ReservedWord 6 0 ReservedWord 7 4003 (fa3H) Write EGD Exchange command number.Word 8 Retry time, in milliseconds The time between retries of command transfers. Default is1000ms.Word 9 Local write buffer memorytypeMemory type for the data, in the local PLC.Word 10 Local write buffer referencetable starting address (leastsignificant word)1-based offsetWord 11 Local write buffer referencetable starting address (mostsignificant word)Word 12 Remote signature EGD Exchange signature. This should be 0 for PLCs when notusing signatures. If run-mode store of EGD will be used, theuse of signatures is highly recommended.Word 13 Remote Producer ID (leastsignificant word)EGD Producer IDWord 14 Remote Producer ID (mostsignificant word)Word 15 Remote Exchange ID (leastsignificant word)EGD Exchange IDWord 16 Remote Exchange ID (leastsignificant word)Word 17 Remote Exchange Offset Byte offset (0-based) in the exchange that should be read.Word 18 Write length Number of bytes to be written in the range 0 to 1400 bytes.Word 19 Network address type Must be 1. Indicates an IP address will be used.Word 20 Network address length Must be 4 for IP address.Group ID (multicast) is not permitted.Word 21 toWord 24IP Address of the remote PLC Four integers, specified as one integer per word of the dotted-decimal IP address of the remote PLC. May not be a group IPaddress.Word 25 Reserved Always 0
