How to wire BACnet field bus for integrating 2 wire and 3 wire MSTP controllers

BACnet MSTP Controller suppliers offer either 2 wire or 3 wire field bus.

BACNet has three wire BACNet Bus and Third party has three or two wire. Below is the configuration that should be followed :

  1. Try to run two different MSTP Buses. ( one for 2-wire and one for 3-wire)
  2. Not more than 30% third party devices are advised. Some two wire devices on three wire BACnet is allowed.
  3. Some Controllers have built-in EOL resistors. 
  4. On Niagara Network the BAUD Rate should be 38.400 for all devices. It should not be set to  Auto.