Omron NQ HMI Getting Started Manual page 30

Multi-drop networks
3-4-2 RS-485 network
3-4-3 Network termination
16
The following wiring diagram is applicable for a RS-485 network (2-wire).
The two ends of a multi-drop network have to be terminated. For the correct
termination of the last NQ-Series in the network, a resistor (120 Ohm) needs
to be applied between R+ (pin 4) and R- (pin 9) on DSUB9 (Male) cable
connector for correct termination.
Figure 3.10: RS-485 network
Section 3-4