Research On Signal Analysis Instrument Based On LabWindows/CVI

Signal analysis instrument is an important tool for scientific research and testing parameters in industrial processes, the structure of traditional signal analysis instrument and function accomplished mainly by the hardware circuit, no function expansions. Computer and equipment technology will be a perfect combination in virtual instruments, make full use of computer technology to achieve or enhance the functions of traditional instruments, advantages of virtual instruments are:simple in structure, short development cycle, the system easy to extend ,and connect to the computer network is simple and easy to achieve information sharing.This paper describes the key technologies of signal acquisition and processing,including hardware components of signal acquisition subsystems,the software structure of virtual instrument system, methods of acquisition card drivers call. And the basic knowledges of signal processing,the features of the virtual instrument software development platform in a brief analysis. Based on these foundations,the paper developed a USB bus data transmission signal analysis instrument on LabWindows/CVI virtual instrument software development platform, to achieve a real-time signal acquisition, time domain analysis and frequency domain analysis.The scheme of virtual signal analysis instrument use the Windows multi-threading technology,allocate the signal acquisition, signal analysis and human-computer interface to independent threads,shortened the time of respond to user operation and increase the system's efficiency.Design the database of the electromagnetic department of Guangzhou Institute of Measuring and Testing Technology equipment verification E-R model,realised the database based on the Access database management system, and visit the database by calling ADO data model , which simplifies the verification data management.Finally, time-domain waveform display submodule of virtual signal analysis instrument based on the LabWindows/CVI was tested, and describes a brief analysis of the error sources,and the attentions need to pay in the virtual instrument verification work introduced.