Engineering notes
A BACnet gateway when the chiller already has a protocol
When you still need a BACnet/Modbus converter between a chiller and the BMS. Read the native points first.
New chillers often speak already
Many chillers leave the factory with BACnet MS/TP, BACnet/IP or Modbus. The BMS needs water temperatures, status, faults, sometimes a setpoint write. If both sides share the standard and the speed — land the cable, map the points, skip the extra box.
Buy a gateway when the chiller is Modbus and the BMS is BACnet only, or when you have MS/TP and an IP-only building network with no router. A “one gateway for the whole building” line usually hides several protocols. BACnet and Modbus