BACnet wiring and controllers are used for Heating and air conditioning purposes. They are networked using the BACnet MS/TP protocol. BACnet is based on a physical RS-485 network. BACnet MS/TP is a low cost, simple to use, way to connect controllers together and allows them to share data. It is a 24 volt AC system that uses only specific kinds of wire, but is best with plenum rated 8 contact wire. Using 1 balanced twisted pair, with low capacitance (17pF or less) 100-120 ohm, balanced. Will work well with CAT5, CAT5E, and CAT6 network cable. If you need BACnet cables made, please give us a call and we can help. Portland Wiring Harness is tooled up to process this kind of wiring system at a industrial rate.