多点温度测控系统的设计

摘要

In order to realize the distributed control of temperature,measurement and control system of multi-point temperature was designed by single-chip technology based on CAN bus. This system utilizes the analog multiplexers and Cold-Junction-Compensated K-Thermocouple-to-Digital converter to measure eight channel temperature samples of type-K thermocouple, and utilizes D/A converter( AD7528) and driving circuit to realize the control of temperature. CAN interface can be composed by controller (SJA1000) ,transceiver(PCA82C250)and optical coupler in this system. The software is made up of PID algorithm in the system. The practice shows that the system has simple structure、better reliability、enough accuracy. By distributed structure, the system can be easily expended with the character of real-time and reliability.%基于CAN总线,利用单片机技术设计了多点温度测控系统,实现温度的集散控制.系统利用多路转换器和新型数字器件MAX6675构成8路K型热电偶温度测量电路,利用D/A转换器AD7528和驱动电路实现温度控制,利用CAN控制器(SJA1000)、CAN收发器(PCA82C250)和光耦(6N137)组成CAN接口.系统软件采用PID控制器.系统输入通道硬件结构简单,采样数据可靠性高,具有较好的测量控制精度.采用分布式结构,易于扩展,具有实时性和可靠性.