外文翻譯--一種新的可燃?xì)怏w報警系統(tǒng)的設(shè)計(jì)與實(shí)現(xiàn)-wenkub
2023-05-19 08:20:09 本頁面
【正文】 required to detect concentration of bustible gas. Relevant national standards bee stricter. Although there are many bustible gas alarm systems in the market, most of them have high misinformation and low performance. The technology of isolated bustible gas alarm is rather mature, but it still couldn’t satisfy the system requirements with multiple nodes and wide coverage. Now most Bustype bustible gas alarm systems are based on RS485 which isn’t very stable and couldn’t acmod ate more detector nodes. When only adopting CAN bus mode, the theoretical value of the online detector nodes is also only about 100. In this paper, the scheme is main controller+CAN/485 converter +gas detector. The node capacity can reach several thousands. The system stability and realtime performance is greatly improved and by bining touch screen, the system’s operation bees easier. The gas alarm system based on this scheme has not been reported until now in China, it’s en important developing direction and has wide space of market and developing prospect.II. SYSTEM PRINCIPLE AND FUNCTION1. System Principle Whole structure of the system is described as gas detectors detect and process gas concentration, and then respond demands of CAN/485 converter to transmit data based on RS485 to CAN/485 ’s structure.2. System Function As is described in Fig1, The whole system includes three levels of part. The main controller municates with CAN/485 controllers based on CAN bus and CAN/485 controller municates with gas detectors and linkage modules based on RS485 bus. Designed maximum number of CAN/485 converter is 32 and it can have 33 gas detectors or linkage modules under each CAN/485 converter. Using this structure, the system ensures the stability and the capacity of detectors reach 1024, so the system can meet the requirements of most customers. Sensor of gas detector detects gas concentration and switches to a 0V5V voltage signal. Then detector analyzes and processes data, converts into the corresponding data format. Detectors transmit data to corresponding CAN/485 converter based on RS485 bus. In addition, gas detectorrealizes functions such as zeroing, calibration, addresses modification and so on. Relay on linkage module controls gas pipeline opening and closing of valves or exhaust fan when the linkage module is set to link with detector and the detector has alarmed, and thus in time to avoid accidents. CAN/485 converter selects ATMega16 MCU as the microcontroller. It receives data from gas detectors and linkage modules and municates with the main controller based on CAN bus. It also must plete functions such as responding and analyzing mands of the main controller, transferring mands to gas detectors and linkage modules to plete specific tasks. In the design of the system, the main controller is most important and difficult part. Its structure is showed as the one hand, displaying realtime concentration information, on another hand, responding touch screen to realize query func
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