When should end-of-line terminating resistors be installed on a BACnet/MSTP network?

Issue

When should end-of-line terminating resistors be installed on a BACnet/MSTP network?

Product Line

TAC I/A Series

Environment

BACnet/MSTP network

Cause

Knowing where to implement the termination helps reduce signal reflections, which might cause issues in the system.

Resolution

Resistors of 120 ohm value must be installed at each end of a MSTP (or RS-485) trunk segment. They help reduce signal reflections and RF interference. Failure to install end-of-line resistors may result in intermittent communications.