Communication Interfaces - Maple Systems PLC-FB0808P User Manual

Communication Interfaces (32 Point PLC)
▶ Serial Port PIN Map
▶ RS-485 Line Resistance Option
If RS-485 communication is not stable because of the surrounding noises, use the "RS-
485 Resistance Option" switch to enhance the resistance. Turning on this option switch
may improve the communication quality, but the available communication distance will
decrease.
PIN NAME
1 TX
2 RX
3 GND
4 D+
5 D-
6 SG
20
COMM
RS232C
RS485