Electric Fire Monitoring System Based On CAN Bus

No matter in petrochemical enterprises or in the department stores, or in the residential buildings, once grounding arc short circuit takes place and effective measures are not taken, leakage fire will be caused, which threatens the lives and property. Such accidents can be avoided or weakened if timely detection is conducted with effective measures prior to the leakage expansion.Firstly, this paper investigates the present situation and development of electrical fire monitoring system, compares their respective advantages and disadvantages. In accordance with the national fire-control regulations, an electrical fire monitoring system is presented based on the CAN bus. The system, with the help of CAN bus communication networks, has a structural mode combining master controller with lower monitor through CAN communication, which assures the effective monitoring of leakage current.Secondly, the paper introduces hardware and software design of master and lower machines. Both of them use high-performance singlechip PIC18F458 as their microcontroller and PCA82C250 as CAN bus receiver and emitter to form CAN communication module.LCD terminal (resolution:128*64) is used to display the pictures and setup the parameters.In addition, the master controller also includes the power conversion and detection circuits, sound and light alarm circuits, printer module, real-time clock, and extended 32KB EEPROM etc.Thirdly, the software design for electrical fire monitoring system is introduced, which realizes special functions such as communication format conversion, automatic search of different nodes, address modification etc.At last, this paper briefly introduces experiments and applications of the system, and summarizes the main problems in application as well as solutions to them.The system can monitor electric fire caused by arc short circuit and can accommodate 255 detectors. The master controller can print alarm record, fault log, and historical records and the LCD makes the user's operating interface convenient and beautiful. Alarm system based on CAN bus is applied widely in the fire-fighting industry. Although rarely reported, the electric fire monitoring system with the structure described in this paper is a major development trend of bus-based alarm system and it will have broad market prospect. This paper is a horizontal cooperation project with Shandong Weifang Baodakeji Co.,Ltd. At present, on account of its advanced design, reliable function, convenient operation, strong anti-interference and effective supervision, the system has passed the project identification of Department of Science and Technology of Shandong Province and the products have been on the market on a large scale and become quite popular in Weifang.