Command Block For The Commreq Function; Example Of The Commreq Function - GE VersaMax PLC User Manual

%M0021
| |
%R0032
CONST
0000
CONST
00020
Serial I/O / SNP / RTU Protocols
For public disclosure

12.1.2 Command Block for the COMMREQ Function

The Command Block starts at the reference specified in COMMREQ parameter IN. The
length of the Command Block depends on the amount of data sent to the device.
The Command Block contains the data to be communicated to the other device, plus
information related to the execution of the COMMREQ. The Command Block has the
following structure:
address
address + 1
address + 2
address + 3
address + 4
address + 5
address + 6 to
address + 133

12.1.3 Example of the COMMREQ Function

In the example, when %M0021 is ON, a Command Block located starting at %R0032 is
sent to port 2 (communications task 20) of the CPU (rack 0, slot 0). If an error occurs
processing the COMMREQ, %Q0110 is set.
COMM_
REQ
FT
IN
SYSID
TASK
Length (in words)
Wait/No Wait Flag
Status Pointer Memory
Status Pointer Offset
Idle Timeout Value
Maximum Communication Time
Data Block
%Q0110
( )
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