Moxa Technologies C168P - Manual (Page 66)

5-10 C168P User’s Manual
RS-485 Cable Wiring for Opt8J
One RS-485 connection box designed for C168P is:
Opt8J: Connection box with 8 female RS-422/485 DB25 ports. Set the port
switch to ON position (RS-485) for the desired port(s).
The Opt8J supports only 2-wire half-duplex RS-485 communication. Data+/- pins
are served for both data transmitting and receiving, depending on the RTS signal.
RS-485 Pinouts for Opt8J:
Opt8J
3 Data+(B)
7 GND
16 Data-(A)
Multidrop RS-485 Half-duplex Point-to-Point RS-485 Half-duplex
Opt8J RS-485 Device 1 Opt8J RS-485 Device
Master Slave 3 Data+(B) Data+(B)
3 Data+(B) Data+(B) 16 Data-(A) Data-(A)
16 Data-(A) Data-(A) 7 GND GND
7 GND GND
RS-485 Device N
Slave
Data+(B)
Data-(A)
GND
See section “RS-485 Programming” of Chapter “Serial Programming Tools” for
more Opt8J RS-485 programming details.
3 Data+ (B)
Data-(A) 16
7 GND