Development Of Parallel A/D Moudle Based On LXI

As a relatively new test bus technology,LXI has got a lot of foucs of many companies and research institutions as soon as it was realeased, after several years of development it has begun to take shape. Data acquisition module is the key to set up automatic test system, so the development of LXI parallel A/D module has high theoretical and applicational value.The thesis uses a combination of ARM processor, embedded Linux operating system as the LXI interface control platform; it takes advantage of a wealth of hardware and software resources of the platform, and makes the instrument-side application development fast and easy.An internally integrated single-chip 8-channel parallel A/D chip is adopted in hardware design; it can meet the design requirements and simplifies the design of hardware circuit. The FPGA which controlles A/D conversion uses Avalon bus architecture in its internal logic design, this makes the logic design take the advantage of the modularization, which can improve the reusability of this design.LXI A class of instruments are required to implement the hardware line trigger and the IEEE1588 synchronous trigger, this thesis presents the related concepts and principles in detail, and introduces how to design corresponding synchronous trigger logic.According to the module functions and the LXI specification, command parsing server programs run on the ARM-side, IVI-COM driver and equipment web interface program run on the PC side, have been designed, and IVI-COM driver contains instrument control interfaces and synchronous trigger configuration interface.Finally, this thesis expounds the result of module test with analyse. In order to ensure the accuracy of the module, an automatic calibration system of this module has been designed, the automatic calibration program bases on calibration model can calibrate parallel A/D module in a short time.After calibration, the instrument's accuracy has greatly been enhanced, on this basis, the instrument error analysis and uncertainty calculation are finished.The test result shows that the parallel A/D moduel on LXI meets the design specifications.