The Software System Design Of In-Circuit Tester

Components on circuit board have kinds of types, containing analog components, digital components, hybrid components, connectors and so on. Along with the widespread application of circuit board, demand of circuit board testing increases day by day. Automatic test of circuit board is a general name of fault detection, fault location and fault identification. In-circuit tester technology is a kind of automatic test technology, which tests various components on circuit board in electronics equipment's production line. This technology has been widely applied in circuit test of electronic product manufacturing and military equipment.The paper carries on analysis to current circuit test theory and technology, also analyzes circuit's characteristics and testing requirements in electronic production line, here designs a new kind of In-Circuit Tester, whose aim is enhancing the test efficiency and reducing the test cost.In order to realize testing function, this subject combines PC computer with Field-Programmable Gate Array, test system's hardware carries on test to components by means of that FPGA control board controlling signal source board, probe group, switch array and test circuit. The core of software system is the test software programmed by Visual C++ 6.0,the software offers human-machine interface, has accomplished design of every test function module and analysis of test data and test results.There particularly introduce and prove test algorithm, test algorithm is an extremely important part in software system. The test system chooses different algorithm to different circuit, so obtains the optimum test vectors generation, take fault detection and diagnosis to circuit with less test times. Specifically in this paper, imports stuck faults test vector generating algorithm and boundary scan test vector generating algorithm.Software system chooses Windows XP as operating system, Visual C++ 6.0 as software development environment and MS Access as system background database, uses information exchange based USB interface in Windows XP environment, so enhances the test system's maneuverability and reliability.Software system's test function is realized by its function modules. In this paper, the software is divided into eight function modules, designs independently and finally they are constructed. According to the design requirements, the software is divided into: jurisdiction setting function module, system self-diagnosis function module, software self-learning function module, program edit function module, test information function module, character abnormity alarm function module, report function module, USB communication function module. The function and design of subfunction module are described detailedly in the paper.The software system has achieved the design demands after testing. Finally, this paper expect the prospects of In-Circuit Tester's development and application in electronic production.