FB3000 RTU Instruction Manual
D301851X012
November 2023
Installation 31
When connecting COM1 to another device using RS-485 (2-wire), use a cable with
configurations as shown in Figure 2-22:
Figure 2-22. Wiring COM1 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.