GE RX3i - Figure 62: COMMREQ Ladder Logic Segment (Continued)

Chapter 9. Modbus/TCP Client
GFK-2224Q January 2017 167
12
13
Figure 62: COMMREQ Ladder Logic Segment (continued)
Rung # 12: When READ_SUCCESS is set it triggers CLOSE_REQ, which enables execution of the BLKMOV, MOVE
and COMMREQ functions for the Close Modbus/TCP Connection COMMREQ. CLOSE_REQ is a one-shot (Positive
Transition) coil, activating once when READ_SUCCESS transitions from OFF to ON.
Rung # 13: The MOVE WORD function moves a zero to the CRS word referenced in the Command Block (see
rung #9). This clears the CRS word. This rung also resets the CLOSE_FLT output coil of the COMMREQ Function
Block in rung #15.
14
Figure 63: COMMREQ Ladder Logic Segment (continued)
Rung # 14: The BLKMV INT functions set up the COMMREQ Command Block contents. When this rung is
activated, the constant operands are moved into the memory beginning at the address indicated in the
instruction. The constant operands in this example are defined in the Close Modbus/TCP Connection Example
in this chapter.