Research And Implementation Of Date Acquisition System Based On USB

As the development of computer science, microelectronics and VLSI, the tradition instrument quits the technology stage gradually in the information age. Instead of the tradition, instrument, virtual instrument technology, which is founded on the combination of computer science, modern measurement technology and tradition instrument comes upon the technology stage and plays a more and more important role the area of electronic measurement.This paper discussed the application of the virtual instrument and USB technology. Virtual instrument characterizes with more functions, higher processing speed, wider bandwidth, more friendly interface, smaller size and better expandability. USB2.0 protocol can provide a speed of 480 Mbps, supports Hot-Plug and Plug-and-Play, and provide suspend mode and resume mode for power management. Taking the advantages of the two technologies, the paper presented the design of a direct attached high-speed real-time data acquisition system. It is a measure instrument system based on PC platform, which is composed a data acquisition hardware card and flexible software.Firstly,the paper presented the design of hardware interface based on USB 2.0 protocol, and the development of firmware on the chip and USB device driver based on Windows driver model. Secondly, the paper presented the design of the data acquisition card and gave an explicit analysis of design of signal conditioning analog circuit. Thirdly, the paper presented the method of application program design and a design of virtual oscilloscope.In the end, the paper gave the summary to the study, referred to some points that need improve in future work, and outlook to the development direction of the virtual instrument technology in the future.