FPΣ User's Manual
11.10 No RS232C Communication
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11.10 No RS232C Communication
A communication error can be detected when monitoring the special relays for serial
communication.
• Check whether the RD terminal of a connected device is connected to the SD terminal
of the communication cassette, and that SD is connected to RD. Make sure SG is
connected.
• Check that link areas do not overlap.
When using FPG-COM1:
Data cannot be sent unless the pin CS (Clear to Send) is on. When connecting to a three-wire
port, short-circuit the RS and CS pins.
• Check if the CS signal is TRUE. If the LED COM.2 R on the CPU is off, the CS signal
is FALSE.
• RS (Request to Send) can be controlled by the SYS1 instruction.