Troubleshooting 
 
FPΣ User's Manual 
270 
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).