ABSTRACT
Building automation and control networks (BACnet) is a communication protocol specifically designed for the purpose of building automation. The basic idea of BACnet is that vendors following the BACnet standard will be able to exchange data on an interoperable basis. The main organization driving BACnet is American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) with their working group SSPC135 maintaining the standard. BACnet specifies three major parts: network media; objects to transport the building automation; and services to transport the data between BACnet devices. BACnet specifies a total of more than 50 different object types. Object types include analog, binary and multistate input, output, and values. The BACnet application layer specifies services for data access, alarming, scheduling, trend logging, and device and network management. In fire-, security-, or access-control systems, BACnet network security features are most likely implemented while this is often missing in building automation components.
