The Research Of The Virtual Instrument Technology Application In Network Measurement And Control System

This paper focuses on the application of the virtual instruments in the network measurement & control system. Virtual technology is one of the most important components in the communication technology, which is viewed as one of the three key scientific technologies in the 21th century. Virtual instruments that can be used to virtual testing and control are essential in virtual technology. The notion of virtual instruments can be described as the user operates a computer under the current operation system according to the definition of requirement and the testing functions that have been designed, as operating a testing instrument that is designed by himself.Through the comparison of some influential virtual instrument systems, the author of this paper chooses the serial virtual instrument system for research and briefly introduces its features, for it is fitting in the field of application research. Generally the virtual instrument system consists of hardware and software and adopts module structure. Software is the most important as well as the most complicated part in the design of virtual instrument. In this paper, the author highlights the approaches how the virtual instrument is structured and the network virtual instrument is realized on the LabVIEW developing platform in American NI Company. According to the subject of this research and the requirement of the serial virtual instrument, we have manufactured the FCS2000, a controlling module used for data acquisition in virtual instrument. Consequently, the author of this paper exploits in details this module in terms of its working principle, hardware frame, software designand its realizing method. During the process of communication module design, various communication interfaces are configured, which enable the virtual instrument to contain multiple bus communication functions with strong universal application. When concerning the Rs-485 communication between personal computer and data acquisition control module, the author of this paper introduces at length the software design and its realizing method in data communication module.Based on the research and design of serial virtual instrument, a concrete example-Train Brake' s Coefficient of Friction detecting system, is introduced in aspect of its all parts working principle and its virtual instrument realizing method. The results of its field use prove that this system runs steadily, tests accurately, achieve entirely the functions requested, and incarnate well the characteristics and the advantages of the virtual instrument technology.