Emerson FB3000 Instruction Manual page 45

When connecting COM1 to another device using RS-485 (2-wire), use a cable with
configurations as shown in
Figure 2-22. Wiring COM1 on the CPU Module for RS-485 (2-wire)
1
2
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.
Installation
Figure
RS-485 (2-wire) port on device
Connect cable shields to suitable Instrument Earth connection point
FB3000 RTU Instruction Manual
2-22:
D301851X012
November 2023
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