Design And Implementation Of Virtual Instrumentation-based Circuit Board Automatic Test System

With the development of science and technology, the electronic system becomes more and more complex, and the requirements of electronic systems on the reliability and maintainability get higher and higher. The circuit board is an essential part of the electronic system in the developing and producing process, and its quality has direct impact on the performance of the system. Thus the circuit board testing is an important link which is related to the quality and producing cycle of the electronic systems. However, most of the traditional circuit board test system is special test equipment, which is designed for single circuit board. In order to meet the automatic testing demand of different circuit boards, a universal test system is urgently needed. Therefore, a circuit board automatic test system based on virtual instrument is investigated and designed in this thesis. The function test and the fault diagnosis of the circuit board are provided in the system, which is of great practical significance and guiding value for the establishment of the open automatic test platform for the circuit board.In the hardware system, the PXI system is selected as the hardware platform. The PXI Instruments connecting to the circuit board through the Test Unit Adapter send encouraging signal and receiving response. The system user can add or delete the function modules according to demand, which makes the system easy for extension. In the software system, according to the level of ABBET standards, the universal software architecture is designed by using the IVI software architecture for reference. In addition, packaging the instrument original Drive in accordance with the norms makes all types of instrument Drive to achieve interchangeability. In the design of software, with the thought of modular programming, the system is divided into seven function modules and the fault diagnosis and universal design are the key technologies. The circuit board automatic test system based on fault tree analysis can locate the fault by logical inference. Besides, an open process configuration platform is established, which makes the users configure the circuit board testing process quickly in accordance with the characteristics and testing requirements of circuit boards. Thus the system which can test different types of circuit boards is realized. In order to test the functions of the circuit board automatic test system, the VI-1508 experiment board is used as the application of this system. The results show that the circuit board automatic test system can complete the work of function test and fault location correctly and with the advantages of strong universality, high degree of automation, easy operating and so on.