Based on the inverse repeat pseudo-random binary sequence and the advanced VXI bus virtual instrument,the dynamic characteristics of the hydraulic servo valve were tested,which shows its vality and accuracy.

After comparing the hardware and software platform of several common virtual instruments, this essay launches a handware platform and a software platform based on VXI instrument and C++ Builder software programming environment respectively according to the application features and environment of ground wave HF radar system.

The article introduces the concept of virtual instrumentation, the hardware and software structure of VXI instrument and its features.

Application of the weft detector using virtual instrument technology;

The research of online measurement and control system for high accurate vertical metal band saw machine based on the virtual instrument;

Development of the temperature and humidity instrument for clothing measurement based on virtual instrument;

Measure and analyze the mechanical capability of the looms on the technique of virtual instruments;

The application of virtual instruments technique in U-H_2 experimental system;

The System of Waste Water Neutrlization Based on Virtual Instruments;