摘 要
本设计是以单片机AT89C51为主控制器,通过CAN总线组建的通信网络进行数据传送的火灾自动监控报警系统。
现场总线接口卡由CAN总线控制器SJA1000,总线驱动器PCA82C250组成,系统上位机通信主要由CAN-RS232通信接口组成。RS232适配卡由转换芯片MAX232搭建,MAX232是AXIM公司生产的CONTENT GOES HERE (simpl一种双组驱动/接收器芯片,采用此芯片接口的串行通信系统只需单一的+5V电源即可。
信号采集控制节点部分主要有温度传感器DS18B20和离子式烟雾探测器实现系统的数据采集,节点控制器选择ATM公司生产的单片机AT89C51。节点控制器可以通过单线驱动温度传感器和烟雾传感器,形成复合式信号采集控制系统。
基于CAN总线的火灾自动监控报警系统,设计的关键在于CAN总线与现场节点控制器适配卡的软、硬件设计;上位机(PC机)和下位机(节点控制器)间CAN-RS232通信适配卡设计;信号采集控制节点设计。
通过实际运行表明,该系统具有容量大、通信距离远、数据传输速度快、组网方便等优点。基于现场总线的火灾自动监控报警系统有着广泛的市场应用前景,是火灾探测报警技术的发展方向。
关键词:CAN总线;烟雾传感器;温度传感器;AT89C51
Abstract
This design uses the monolithic integrated circuit AT89C51 as the primary controller, sets up the correspondence network through the CAN-BUS to carry on the data transfer the fire automatic monitoring alarm system.
The fieldbus connection card is composed of CAN-BUS controller SJA1000 and the bus driver PCA82C250. The up-PC communication of the system is mainly composed of CAN-RS232 communicate connection. The RS-232 adaptation card is built by the transformation chip MAX232, MAX232 is a double drivers/receivers chip made by AXIM enterprise, the serial communication system which uses this chip only needs a +5V power.
The system signal collecting node part mainly uses temperature sensor DS18B20 and ionic smog detector to realize the data collecting of the system, the node controller takes the monolithic integrated circuit AT89C51 made by ATM enterprise. The node controller may form the compound expression signal collecting system, using the single track drove temperature sensor and the smog sensor.
Taking the CAN —BUS as the foundation automatic control system, the key problem of the system are the software and hardware designs of the Fieldbus and field node controller adaptation card; the design of CAN-RS232 communication adaptation card between up-PC (PC) and down-PC (node controller);the design of the signal collecting control node.
Through the actual running, it indicates that this system has a large capacity; far communicate distance, quick data transmission, and convenient forming net. The system based on the fieldbus has a widespread market application prospect; it is the development direction of the fire automatic monitoring alarm technology.