FB3000 RTU Instruction Manual
D301851X012
November 2023
34 Installation
When connecting COM2 to an RS-485 (2-wire) port on another device use a cable with
configurations as shown in Figure 2-25:
Figure 2-25. Wiring COM2 on the CPU Module for RS-485 (2-wire)
RS-485 (2-wire) port on device
Connect cable shields to suitable Instrument Earth connection point
Regardless of the interface standard – RS-232, RS-485 (4-wire), or RS-485 (2-wire) – you
must use FBxConnect to configure the port for proper usage.