The Research And Design Of Virtual Instrument Based On USB Interface

The technology of USB is one new standard of industrial bus in PC system. At the present time, USB port not only has been the standard port of the main board of PC,but also trends to substitute the other bus interface such as serial interface, parallel interface and so on.USB is abroadly applied in all kinds of peripheral equipment of PC and it is cheap, high speed, low power and support Plug&Play. It's convenient in use and maintenance.With the development of computer technology, the power of personal PC is becoming greater and greater, and the technology of virtual instrument which is being develop at very fast speed has great foreground.It will become one new trend to apply the technology of USB in cheap measure instrument.Logic Analyzer(LA) is one basic tool of Data Domain Measure. It is a kind of instrument with wide application in research, teaching and manufacture.Virtual instrumentation technique is developed upon both instrument technique and computer technique. This technique is considered as the future trend of instrument technology. The first part of the thesis has a review-like character. It makes a brief introduction of the logic analyzer technique, which including logic analyzer's concept, main function. The thesis also introduces the virtual instrument's concept, system architecture, etc. The thesis mainly discusses the design of virtual Logic Analyzer, based on USB interface.The principle of Logic Analyzer is addressed. After requirement analysis being surveyed, the system framework is presented. The instrument is made up of two parts: application software on personal computer, and the data-sampling system based hardware circuit board.This project mainly use the USB theory, Virtual instruments theory and some knowledge include software and hardware to perform the research of Virtual instruments system based on USB. In this project, I had accomplished compiling firmware programme of MCU, compiling WDM programme, Delphi programme and so on, and involving knowledge have C/C++, Assembly Language, USB bus, 2000DDK, DriverWorks and so on. After integration debugging, it has been successful to transmit data from bottom hardware to application software andaccomplish the initial prototype of virtual instruments system based on USB.In the end of the thesis, a summary is presented and some suggestions are forward to improve the instrument.