The Measurement And Control Network System Based On CAN Bus And It's Application In Fresh Air System

The fresh system is scanty system that absorbs solar energy and heats up fresh air. The application in the energy supply and ease pressure on the strategy of sustainable development has important significance . CAN (Control Area Network) field-bus technology is a very safety serial bus which can support distributed real time control. It mainly realizes digital communication between intelligent devices and resolve the problems of information transfer between field control devices and higher control system.In this paper, the design of intelligent node based on can bus. It's main tasks includes intelligent node overall circuit design, components selection and software program, can bus communication program. The intelligent node comprises microprocessor, can bus controller, integrated can module circuit of setting node address, display circuit, keyboard circuit, control interface circuit, power supply circuit and reset circuit mainly. Others this node consists of A/D, D/A, EEPROM, FLASH , DS18B20 and I/O equipments. Intelligent node overall function is monitoring temperature, pressure and flow parameters real—time. According to needs is able to control electric valve real-time. The node can accept orders from PC to implement it and return the results. The design of the new air control system. The new air system includes temperature sensors, flow sensors, pressure sensors, flow control valve, the on-off valve components. Intelligent node controls those equipments in order to achieve six kinds of operation node.