The Design Of A CAN Based Building Automation System

The thesis introduces the design of a CAN based building automation system.By the analysis of the evolution and the various features of control systems,it is pointed out that the field buses including CAN are of advanced properties and will be widely used in the field of control applications.The designed CAN based building automation system is composed of front-end modules and a PC with communication card as the system supervisor.The front-end module is an intelligent unit designed around 8051 micro-controller,with I/O interfaces to perform data acquisition and control action,the CAN interface is designed by using SJA1000 CAN controller chip to fulfill the network communication tasks.The communication card mount in PC uses CH365 to link PC's PCI bus and perform data exchange to/from CAN bus via SJA1000.A simple communication protocol is designed based on the CAN's physical and data link layer protocols.The protocol fulfills the tasks of equipment identification,reliable data transfer,network control.The application of CAN based building automation system will raise the intelligence level,decrease the cost of management,and improve the reliability and safety of the building.Obviously,such a system is of broad application prospects.