User`s manual

5-12 Smartio C168H/PCI User’s Manual
RS-485 Cable Wiring for Opt8J
One of the RS-485 connection boxes designed for Smartio C168H/PCI is:
Opt8J: Connection box with 8 female RS-422/485 DB25 ports. Set the port switch to
the ON position.
The Opt8J option only supports 2-wire half-duplex RS-485 communication. Data
+/ − pins are used 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
3 Data+
(B)
7 GND
Data- (A)
16