Communications Protocol for a Building Automation System
J.S. Botic · 2005
With the advent of microprocessors, it has become economical to distribute some of the building automation system (BAS) functions, once reserved for centralized minicomputers. With this comes a need for an efficient and economical communications protocol. Of chief concern in a BAS system are system response times and information throughput. Standard protocols (e.g. SDLC, HDLC, ADCCP, X.25, CAMAC) are general purpose protocols with high overheads. The high overheads associated with these protocols makes their use inefficient in a BAS. This paper describes the design considerations and tradeoffs in the design of JCI's proprietary BAS protocol. This protocol is a byte oriented, variable length polling protocol intended for use in several levels of distributed BAS networks.