When should end-of-line terminating resistors be installed on a BACnet/MSTP network?
TAC I/A Series
Knowing where to implement the termination helps reduce signal reflections, which might cause issues in the system.
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.