Functional safety in building automation and control systems

The building automation and control systems (BACS) help building owners, property managers, and occupants realize their goals in the areas of cost, comfort, convenience, long-term flexibility and marketability. With the merging of computer, communication and control technology in BACS, the devices, communicationpsilas and controllerpsilas failure will lead to functional safety problems. Thus the functional safety depends on the accurately executing the functions of device, communication and controller. First, this paper gives a survey of functional safety in BACS. Possible risks and failures are discussed. Then, a systematic, bottom to up realization method is presented to ensure the function of BACS. It includes a design model of functional safety-related device, several functional safety mechanisms to guarantee the communication reliability. The relevant works such as human management, safety lifecycle are also mentioned.