Troubleshooting
11.9 No RS485 Communication
A communication error can be detected when monitoring the special relays for serial
communication.
•
Make sure the transmission cables have been securely connected between the two
(+) terminals and the two (-) terminals of the stations.
•
Make sure the characteristics of the transmission cables are within the specified
ranges. See "Transmission Cables" on page 94.
•
Make sure all of the cables in the link are of the same type.
•
Make sure the terminating resistors have been correctly set on the first and on the last
station only.
•
Check that link areas do not overlap.
When using FPG-COM4:
When the RS485 port (COM port 1) of FPG-COM4 is used, set the baud rate in the system
registers to either 19200bit/s or 115200bit/s. Set DIP switch SW1-2 of the cassette to the
same setting (see page 162).
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FPΣ User's Manual