The Research Of Measure And Control System Based On Virtual Instrument Technology

With the development of micro-computer technology, software technology and network technology, virtual instrument technology has made great progress in the domain of electronic measurement and automatic control. The emergence of virtual instrument, lias opened up a new era of testing technology, is a revolution in the field of measurement and control. Meanwhile, it represents the latest trends in the development of measurement and control technology, and has played an important impact on industrial production and development of science and technology. The technology makes full use of computers' powerful function in display, computing and storage, completes the data collection, processing, control, analysis, storage and displaying the results by the corresponding high-level software modules, thus replaces a variety of traditional instruments.In this paper, a galvanizing plant hot-dip galvanizing system is chosen for study. The Design of Measurement and Control System based on virtual instrument technology is completed according to zinc pool temperature and the technical specifications of fluxing agent in the ferrous iron content. Firstly, the paper briefly presents the current development situation of virtual instrument technology at home and abroad. Then, it mainly introduces the issues-related technologies, the hardware circuit designing and host computer software developing. Hardware circuit design section focuses on Temperature Sensor and choice of Microcontroller, Temperature signal and concentration signal magnification and Analog/digital conversion circuit design, Data Transfer Circuit Design which includes achieving long-distance data transmission by CAN bus and realizing the communication between lower computer and host computer by serial interface.System host computer software is designed by Virtual Instrument Development Platform LabVIEW to realize the process of measured information and generation of control signal. Software design section mainly realizes the serial communication between next-bit machine and computer by VISA instrument driver technology; it utilizes the free LabVIEW Database Access Kit LabSQL provided by NI Corporation to access the Access 2003 Database, and makes database employ in the data management of measurement and control system, which makes the measurement and control system functions more perfect. Meanwhile, the LabVIEW Plug-in PID Control Toolkit is to control program, it Verifies control system performance through the precise control of simulation parameters. Meanwhile, optimal design of host computer program and how to publish applications are illustrated. Finally, the thesis research are summarized and prospected.The analysis of experimental results indicates that this measure and control system has reasonable fiame, intuitive interface and simple operation. Its work efficiency is high and reliability is good. At the same time, it shows that the system lays a good foundation for the practical application at the factory.