The Research And Design Of Fault Detection System For Circuit Board Based On Labview

This issue takes the research of a certain air control board's fault auto-detection system as the background. According to the testing requirements, the air control board fault auto-detection system is designed and implemented. It includes the following characteristic, the integration of system hardware platform, test automation, fault location automation, automatic power off when faults occurred, and good human-machine interface. Based on the analysis of build methods of test platform at home and abroad, this paper presents a common platform of air control board'fault auto-detection system which is based on PXI bus, PXI-1045 chassis, MXI-4 optical fiber communications, NI card, the Labview8.0 and LM3S600. This approach puts forward a fault automatic test system for the traditional circuit test's heavy work and also avoids the non-standard personnel operating. The test result is transmitted to the remote computer via Ethernet so that the engineers can confirm the fault condition. As a result, this method improves the reliability and speed of the test.In term of the hardware, after analysis the requirements of the test outline and the test item, PXI board is selected as the basis of the system's hardware. In addition, the design of the system is composed of the HMI based on Labview8.0 professional development version, PXI-1045 chassis, MXI-4 fiber optic communications, and the transmitting of the testing process to remote control PC via Ethernet. What's more, an electronic load board based on LM3S600 is designed for the matching circuits of old and new equipment.In reference to the software, Labview8.0 professional development version is used as the basis of the design of HMI. Under this kind of software environment, the design and debugging of the system was carried out. The work consists of the implement of Labview software's frame structures which is based on the state machine and event structure, the calling of sub-item in test requirements which is achieved through the dynamic calls and search in the database system using the LABSQL, the automatic location of the fault point based on the query in Access, the analysis and real-time display of the test data, and the remote transmission of test data via web publishing tool.By the on-site debugging and trial of the system, it is proved that the system is running stable, and achieves all functionality as expected. It presents that the design has positive meaningful to improve the rapidity of circuit board's fault detection and ensures the quality of product.