External resistors are required for Biasing and Terminating RS-485 trunks connected to an Automation Server (AS)

Issue

External resistors are required for Biasing and Terminating RS-485 trunks connected to an  Automation Server (AS)

Product Line

SmartStruxure Solution

Environment

SmartStruxure Automation Server (AS) with  RS-485 trunk(s) under it.

Field controllers on the RS-485 trunk; for example, the Network 8000 ASD controllers (MZ2, PEM1, etc) 

Cause

Bias and terminating resistors are not built into the AS hardware.

Resolution

External resistors are required for Biasing and Terminating RS-485 trunks connected to an  Automation Server (AS).

See the Technical Reference Guide, revision 1.3, pages  2723, 2724, and 2771.

 

Also check out the SmartStruxure-RS485-Network Installation Quick-Help video on the Exchange.