Applied Research On Automatic Test System Of The Loadboard Based On LabVIEW

The paper is made under background of loadboard automatic testing system of 709 th research institute of China shipbuilding industry corporation. According to the technique demands, an loadboard testing system is researched based on LabVIEW, and it can satisfy the demand of testing transmission rata between 200 Mbps and 3.6Gbps. Due to the continuous development of the virtual technology, Automatic test system based on virtual instrument technology have been adopted widely by foreign countries and are developing in our country. In the text,a testing system is designed based on LabVIEW, NI instruments and GPIB bus. The testing solutions method of the speed up to 10Mbyte/s of GPIB bus to communicate can solve the problem of the traditional test method in the low speed. The method of measuring the loadboard with programmable instrument can solve the problem of the traditional test method in the low reliability. The method of using the software LabVIEW of NI company to programming can solve the problem of traditional test method in the low scalability.The automatic test system need complete two parts of work including the hardware and software design.As to hardware, the pin spacing of loadboard is small and its signal output points are pads, which makes it hard to be positioned accurately even by a probe. Therefore, special adapter is required to amplify pin spacing of loadboard. In order to ensure the accuracy of the test result, almost no distortion of signal would incur when passing the adapter. On this basis, we can design the fixing device of loadboard, choose the appropriate and proverb,and oscilloscope with high performance.With regard to software, it needs to analyze how programmable instrument tests the loadboard before compiling testing software. According to the analysis, the fitting mode of the high-speed oscilloscope is chosen as the sine interpolation, sampling method is chosen for real-time sampling, and the sampling rate is higher than the bandwidth of more than five times. In the compiling environment of software LabVIEW 8.2 made by American NI Company, the software interface of visualization is designed based on modular design concept. By debugging the sub module and overall, the software can measure rise time, error rate, signal attenuation, transmission rate of loadboard. A serial of VIs in free software LabSQL are used to realize the function of saving the real time test results in the database and printing them according to needs.By installing and debugging the loadboard automatic testing system in the field, it is can be concluded that the system can run stably in high transmission rate, and can satisfy the requirements of users.