The Design Of Circuit Board Functional Test System Based On Virtual Instrument

Functional test is to provide simulation running environment of the circuit to be measured, make it work on a variety of design state, so as to get to the various condition parameters to verify the function of the measured circuit board. General points printed circuit board assembly of functional circuit test.PCBA is main part of electronic products, and PCBA's function is becoming more and more complex now. If we choose traditional instrument to test different functions in a PCBA, we must need many kinds of instruments, this will increase the complexity of the test system. In the analysis of domestic PCBA automatic test system test method basics, the PCBA functional test system is designed based on Lab VIEW, NI board, PXI bus.Based on the problem that traditional testing method is not reliable and maintainable, a new testing scheme of using the rapid and steady board is presented. Based on the problem that the traditional testing method is bad in durability and visibility, a testing method of using the Lab VIEW development software is presented.As to the hardware, functional circuit test system based on PXI bus, NI data acquisition board and relay board is designed by analyzing the testing object of the system. In the system, PXI bus, NI data acquisition board and relay board is the core of control. In the network, there is a lot of har dware including PXI bus, 18 slots PXI bus crate, programmable power supply, test fixture and so on, which can satisfy the demand of data acquisition.As for the software, with the thought of modular programming, the system is divided into five function modules. By programming the bottom drive layer and parameter adjustment, the basic voltage, current and frequency measurement can be realized according to users' demands. By using the technology of Active X, the testing result can be preserved into Word.Through the experiment is used as the application of this system,the results show that the test system has the advantages of strong universality, good scalability, easy operating and so on.