YASKAWA MP920 User Manual page 178

7 218IF Module
7.6.2 Communications Ladder Logic Programming
Programming Precautions
Care is required when one 218IF Module is communicating with 11 stations (11 connec-
tions) or more. This is because there are only 10 channels of shared memory between the
CPU and the 218IF, and these channels will be used until the system function has been com-
pleted. In other words, the 218IF cannot communicate with 10 stations at the same time.
When the 218IF is communicating with 11 stations or more, one channel must be used by
two stations and the communications destination must be switched using the ladder logic
program so that the 218IF communicates with the second station only after it has finished
communicating with the first station. In this case, the EXECUTE system function must not
be set to ON (SB04) all the time.
CPU Channel
1
2
3
10
218IF
Connection 1
2
3
4
19
20
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