FPΣ User's Manual 
 
8.2 Communication Cassettes 
159 
8.2 Communication Cassettes 
There are several types of communication cassettes, each having a particular field of 
application (see page 
163): 
Types 
•  FPG-COM1: 1-channel RS232C type (see page 
159) 
•  FPG-COM2: 2-channel RS232C type (see page 
160) 
•  FPG-COM3: 1-channel RS485 type (see page 
160) 
•  FPG-COM4: 1-channel RS485 and 1-channel RS232C combination type (see page 
161). 
 
8.2.1  Communication status LEDs 
The labeling of the communication status LEDs on the CPU refers to the 2-channel RS232C 
type communication cassette (FPG-COM2). For all other types, the following table applies: 
 
LED  FPG-COM1  FPG-COM2  FPG-COM3  FPG-COM4 
S 
SD SD SD RS485: SD 
COM1 
 
R 
RD RD RD RS485: RD 
S 
RS SD — RS232C: SD 
COM2 
 
R 
CS RD — RS232C: RD 
SD: Send Data (output)  RS: Request to Send   
RD: Receive Data (input)  CS: Clear to Send   
The LED flashes while communication is taking place and goes out when there is no 
communication. 
 
8.2.2  FPG-COM1: 1-Channel RS232C Type 
This communication cassette is a 1-channel unit with a five-wire RS232C port. RS/CS control 
is possible. 
Terminal layout 
 
Pin  Name  Signal direction  Port 
SD 
Send Data 
PLC → External device 
RD 
Receive Data 
PLC ← External device 
RS 
Request to Send 
PLC → External device 
CS 
Clear to Send 
PLC ← External device 
SG 
Signal Ground  — 
COM 1 
 
RS (Request to Send) can be controlled by the SYS1 instruction. 
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.