Design Of Networked Virtual Instruments Experiment System Based On LabVIEW

It is very important for experiment teaching in the entire teaching of high engineering institutions, but in a long period of time, the backward teaching instrument and teaching method have restricted the improvement of teaching quality in large degree. Along with the development of the microcomputer, compare with traditional instrument, the virtual instrument have the obvious technical advantage in knowledge ware, processing capability, the ratio between function and price and Maneuver ability. The introduction of the virtual instrument to the university can not only increase the efficiency and quality of testing teaching, but also provide the effective method to reduce the cost of the experiment instrument. and gradually perfect It has the peculiarity of low cost,high performance test means. The purpose of this thesis is to build a teaching testing system of virtual instruments, which can be severed to experiment teaching of high engineering institutions, and upgrade its teaching level and improve its teaching quality.The application of internet in the long-distance monitoring was taken as research background and the accomplishment of experiment system in the internet was taken as research purpose in this paper. The development of related subject around the world was discussed firstly. Then introduces virtual instrument development software LabVIEW. To overcome the shortcom- ing of high cost which the data acquisition card produced by the NI company has, the data collection by means of Universal Serial Bus was adopted in the experiment system.A new kind of Data Acquisition System is designed in this thesis, which is based on Universal Serial Bus(USB) technology with data acquisition, analysis and display together. The advanced performance of USB with high speed, HotPlugIn, Plug and Play, easily to expand and engrossing less system resource is shown in the system.The thesis introduced the design of the USB driver of this data acquisition system. the application program based on LabVIEW such as Virtual Oscillograph, Virtual Signal Generator, Virtual Butterworth Filter, Virtual Amplitude Modulation and Demodulation Instrument, Virtual Differentiator and Integrator, Virtual Experiment of Correlation Analysis and so on, is completed. The Virtual Oscilloscope not only has the functions achieved in traditional scope such as waveform display and control, but also achieves some expanded functions. For example, the parameters can be measured and displayed automatically, the waveform can be saved and printed, further more, the spectrum of signal can be analyzed and displayed.This thesis details the means of realizing communication through network by DataSocket, Web Server and Remote Panels technology in LabVIEW. Finally, this thesis provides a summary of the research work and makes some recommendations for the future research.