W-4: Com Port 3 Wiring - Automation Direct CLICK PLUS PLC Manual

Chapter 4: PLC Communications

W-4: Com Port 3 Wiring

W-4
Com Port 3 supports 2-wire RS-485.
3 Pin
Terminal Block
Wiring Strategy
You need to connect all + signal terminals in the network together. You will also need to
connect all – signal terminals together. It is optional to connect the logic ground.
NOTE: The resistance of the termination resistors needs to match the impedance of the communication
cable.
NOTE: Use a repeater if connecting more than 32 slaves to Port 3.
4-18 CLICK PLUS PLC Hardware User Manual, 1st Edition, Rev. B – C2-USER-M
Port 3 Pin Descriptions
1 + (Plus)
2 - (Minus)
3 LG
RS-485 Port on
another device
CLICK
Com Port 3
RS-485
+
–
LG
Add a termination resistor between
the + and – terminals on Port 3.
Signal A (RS-485)
Signal B (RS-485)
Logic Ground (0 V)
RS-485 Port on
another device
+ +
– –
LG LG
Add a termination
resistor between the
+ and – terminals on
the last device.
Optional (Some devices may
not have this terminal.)