基于HART总线对过程量测量和控制实验的改进

Improvement of Experiment of Process Measure and Control Based on HART Bus

液位、压力、流量和温度是过程工业的四个主要控制参数。针对目前过程量测实验所用的A/D数据采集卡在数模转换过程中造成较大误差的问题,本文使用HART总线对实验做出改进,使检测和控制结果更加精准。HART协议通信的特点是在现有模拟信号传输线上实现数字信号通信,基于HART总线的过程量测量和控制实验系统由管路系统、传感器、HART总线设备、驱动电路、电机以及水泵构成。使用Lab VIEW编程实现HART总线的数据采集、数据处理、控制和串口通信等功能,并通过温度实验的结果,验证了HART总线对实验的改进效果。

Liquid level,pressure,flow and temperature are the four main control parameters of the process industry.A / D data acquisition card causes great error in digital to analog conversion process. This paper uses HART bus to make improvements in the experiment, and the control results more accurate. The characteristic of HART protocol communication is to realize the digital signal communication in the existing analog signal transmission line. Process measurement and control experimental system based on HART bus are composed by the pipeline system,sensors,HART bus device,drive circuit,motors and pumps. In the aspect of software,data acquisition,data processing,control and communication functions are programmed by using Lab VIEW. Comparing with the temperature experiment＇s result,it can verify the improvement of the HART bus experiment.