Software Design Of Test System Based On Virtual Instrument Technology

The virtual instrument (VI) is a major breakthrough of the traditional instrument, which uses advanced bus technology to combine test function of instrument hardware and rich resources of the computer together to improve the instrument modularity, flexibility and degree of intelligent. This project combines virtual instrument technology and PXI bus technology and successfully completes a comprehensive test system and designs a series of test cards with standard bus.This paper first introduces the development status at home and abroad and research significance of virtual instrument technology, then roughly introduces the overall needs, design basis and soft, hardware overall design scheme of the system, then introduces the design and realization of software in embedded controller side and PXI test cards of test system, as well as issues and problems encountered in the design and development work solutions in detail.Software of embedded controller side in the test system is divided into four parts:the WDM driver, the VISA interface library, board drivers and GUI interface program. For WDM driver, based on introduction of WDM driver model, this paper gives a way to design WDM driver using Windows DDK (Driver Development Kit) and VC++6.0; for the VISA interface library, this paper introduces key data structure and key functions to design the VISA interface library based on VC++6.0; for board drivers, we introduce the VPP driver and IVI driver mode first, and then give a way to design VPP driver; for GUI program, this paper first introduces LabVIEW programming models and then show specific application of them in the design.Internal software of PXI test cards in the test system is divided into three parts: communication module, information parse module and test function module. For PXI communication module, this paper presents designing principle and implementation process; and for information parse module, this paper describes the program’s design ideas and algorithm design based on investigating the usage of this module; for test function program, this paper only describes the realization principle of this module based on the introduction of the communication interface of the CPU and FPGA. Testing and user experiments show that this test system has realized test functions of analog port, digital port, V.24port, V.35port, E1port, Ethernet port of SWCs, INCs, Communication Controller, Optical Equipments, K/RS232converter, V.35interface converters and other equipments, test results are reliable and indicators and functions of the system have met customers’requirement.