Automatic Measurement System, Based On The Open Space Of The Virtual Instrument Technology Performance

This thesis introduces basic feature of the Virtual Instrument technology used in instrument control domain. It presents the model of modern instrument control and the major standards involved in the area such as GPIB interface,RS232 interface, etc. It analyzes the structure , principle and character of VISA and SCPI. It introduces the combination of the VISA and SCPI technology as I/O control of instrument in developing EMC automatic measuring project. It employs Lab VIEW as application development platform because of its popularity, powerful function, simplicity of learning and programming.Based in Virtual Instrument technology, this thesis applies the modulating method and develops a EMC automatic measuring system using the combination of Lab VIEW, C51 language and hardware. The system includes the unit of instruments controlled in the basis of GPIB interface and the unit of antennas switched in the basis of RS232 interface. Finally we use the system to measure and analyze the capability of the Open Area Test Site.The system has so many advantages such as friendly interface, convenient manipulation, comprehensive functions, etc. The test indicates that EMC automatic measuring system enhances the stability of measurement, avoids man-made reading errors, calculation errors and deflection as result of not recording correlative data at the same time, increases the precision and efficiency of the measurement. It has high values of application .