The Automatic Discovery And Control-Measurement Of The Instruments

Along with the use of instruments in various fields, from research laboratory to industrial workshop, automation instruments are everywhere. People realized to collect useful data changes over time and need some way to capture and complete data record. Once the computer is connected to the instrument, data collection, analysis and control, and so on function can be extended freely. Using grown-up and wide application of network technology, instrument measurement system has been based on the application of Internet technology to LAN bus network measurement system from the traditional RS232, CAN, such as USB bus measurement system, different interfaces, different types of a large number of instruments connected to the test environment, need to the management of the instruments. To uniform interface standard, the United States National Instruments (National Instruments, NI) proposed the Virtual Instrument(Virtual Instrument, hereinafter referred to as VI) concept, combined with the IVI technology (Interchangeable Virtual Instrument, IVI) to realize the control and measurement, through the computer software will the computer hardware resources and Virtual Instrument hardware together, thus turn powerful computer processing power and Instrument hardware combined measurement and control ability.In order to realize the virtual instruments management, including local investigation found that IVI driver management, equipment management, to swap the configuration of equipment, complete of IVI instrument interchangeability requirements, improve the management efficiency of the instrument to a great extent and the test efficiency, this paper used virtual instrument technology to equipment management and operation as the foundation, according to the characteristics of the networked instrument, designed to unified management of the virtual instrument system, can according to local resources and instrument driver management basic function such as configuration, and query. Based on the virtual instrument technology, design a set of virtual measurement and control platform with interchangeability, can accord to different instrument simulation and entity instrument measurement and operation. After studying VISA and IVI technology, this paper realized the instrument hardware basic detection function by VISA, through the IVI technology to realized the swaps and the real operation of the instrument, and combined two techniques to complete access to physical hardware and operating.This paper designed the architecture of virtual instrument is the in-depth analysis and research, the main contents include:VISA, LXI bus technology and IVI technology specifications, through the study of the content and integrated, the understanding of the principle of operation of virtual instrument and be able to build virtual instrument working environment, analysis of the working relationship between hardware and software of virtual instrument and process. Secondly analyses IVI technology in detail, from the internal mechanism of IVI analysis the specific flow of IVI instrument interchangeable. On the realization of the system, this system combined with the Python language, with its efficient, flexible, and has the characteristics of object-oriented, combining Pyqt4, NumPy Matplotlib and powerful extensible modules, and backend support IVI and VISA technology, combined instrument detection and management and instrument measurement functions, improve the test efficiency of virtual instrument, to implement instrument management, drive and instrument interchangeable measurement purposes.