Rockwell Automation 1771-KA2 Communication Adapter Module - Manual (Page 120)

Start–up and Troubleshooting
Chapter 9
9-18
Testing the Receiving Station
The receiving station is checked with the sending station for one
purpose--verification of data transfer. Although this procedure may be
time-consuming, it is essential in initial start-up testing and for testing
whenever a command is added at a station.
The station communication adapter module, upon receiving a command
message, executes the command at its station processor, and formats and
transmits a reply message back to the sending station. START/DONE and
REMOTE/LOCAL FAULT bits indicate proper execution of this
procedure.
The checks performed in testing the sending station, therefore, can
indicate and help to isolate the source of a problem that prevents the
command from being executed. The checks at the receiving station help to
verify that program addressing and station number switch selection is
correct and that data are being sent to the intended station.
When a command has been initiated and tested at its sending station,
perform the following procedures at the receiving station.
1. On the programming terminal at that station, display the instructions
for the application program that are affected by data transferred from
the sending station.
To identify areas of the program that are affected by transferred data, refer
to Form 5033, which is recommended programmer documentation for
each station.
2. Observe that the data at these locations matches the data in the
proper locations at the sending station processor. For write or read
commands, observe instructions that address transferred words in the
program at the receiving station processor. (These instructions
include GET, PUT, TON, TOF, RTO, CTU, and CTD.)
For bit write commands, observe the ON/OFF status indicator for
instructions that examine those bits in the program.
The same tools and procedures used in start-up of a station containing a
communication adapter module can be used for troubleshooting. This
section outlines procedures that can be used in addition to the start-up
procedures of section titled “Start-up Procedures.” Troubleshooting