Study Of High-speed Data Acquisition System Based On Virtual Instrument

At present, the data collection technology has gained broader application. At the same time, people bring higher target against the data acquisition index. Nowadays, the universal high-speed data collection card commonly adopts PCI or ISA card. It has the shortcomings as follows: difficult to install; high prices; poor expansibility; unable to make electromagnetism shied in some strong electromagnetism locale.The paper adopts a new pattern communication criterion USB,and develops a high-speed data acquisition card. The system has successded in virtual instruments' explointation. The hardware result is an airtight device and the software plat has a friendly graphic user interface (GUI) which makes the system simple and powerful in practical usage. The rate reaches 24Mb/s which reaches advanced level in home.At first the paper introduces the basic theory of data acquisition, the data acquisition process, two sample patterns(real time sampling and equivalent time sampling). The paper discusses the data acquisition system next. It includes the data acquisition system's form; structure; channel scheme; interface scheme and hardware design. And it describes the main chips and technology used in the system. Particularly it introduces the USB system structure; the transmission mode of USB and the characters of USB2.0.The paper exploits firmware program. Here makes particular description to the frame program and function program. On the software side, it designs and passes the driver and application program. At the same time, the paper shows the test result of the data acquisition system using LabWIEW as software flat.Hardware and software of the high-speed data acquisition system has reaches design need and is setted in the virtual instrument developed by China University of Geosciences.