GE GFK-1541B manual

4

ƒThe IN field points to the starting location of the Command Block parameters (%R00301 in this example).

ƒThe SYSID field of the COMMREQ Function Block defines the target rack and slot of the Ethernet Interface to receive the command data. This is a hexadecimal word value that gives the rack (high byte) and slot (low byte) location of the Ethernet Interface module. In the example ladder diagram shown, which is taken from a VersaPro screen, the first three number places (from left to right) are zeros and are not displayed; only the last number, 4, appears. This indicates rack 0, slot 4.

ƒThe TASK field of the COMMREQ Function Block indicates which mailbox task ID to use for the specified rack and slot. For the Series 90-30 Ethernet Interface this value should always be zero.

ƒThe FT output (energizes the CLOSE_FLT coil in this example) is turned ON (set to 1) if there were problems preventing the delivery of the Command Block to the Ethernet Interface. In this case, the other status indicators are not updated for this COMMREQ.

Rung # 16: When ETH_READY is set the CRS word for the Close Modbus/TCP Connection commreq is monitored for a status of 1, indicating that the Close commreq completed successfully. The CRS word change to 1 sets coil CLOSE_SUCCESS.

4-32 TCP/IP Ethernet Communications for the Series 90™ PLC User's Manual– May 2002 GFK-1541B