Applications Of USB Technology In Tester Of Residual Current Protective Devices

GB13955-2005, new national standard, put a higher demand to operated-characteristics tester of residual current protective devices. Many manufacturers develop their own testers based on singlechip technology. And the function of these testers is simple, test accuracy is limited, and intelligentized degree is not highly. 'New operated- characteristics tester of residual current protective devices based on ARM technology' makes use of SOC technology to achieve user-friendly graphical interface and control the constant current source to realize stipulation spike scope the multi-spots scanning test automation the operated-characteristics parameter of residual current protective devices. It also stores and processes parameters for a number of products, and realize test data gathering, display, storage, and intellectualization of data processing.Based on the ARM embedded processor SEP3203 of Southeast University, the project has set up the development platform possessing the embedded OS, This will be used for constant current source control and detection information processing system. Using the standard test signals of NC constant current source for measuring residual current protective device characteristics, measurement results preservation of specified the text document in flash. Meanwhile, in order to facilitate manufacturers or power supply system to manage a large number of test data, it uses VB.NET to develop "the management system for detection information". Through USB communication interface, the test device processes the contents of the documents of the testing results and transfers them to PC database, then do classified statistic according to the need for the work, demand inquiries and forms statements.Firstly, the paper introduces the USB technology and analyzes USB protocol and necessary function of host in the embedded system. Secondly, it introduces the USB device genus (Mass Storage) and how to realize the USB interface in the embedded system. Thirdly, the paper designs the experiment model of MCU+USB interface chip and finishes the design of hardware. Lastly, for the software requirement of the USB host, we have programmed in embedded system to realize USB protocol stack, USB mass storage protocol and FAT files system wildly used in PC field. The program design is also explained in details combining with flow chart.The project belongs to the encourage the development of high-tech projects on state and has been the development of science and technology in Huaian City Technology Fund dollars for 2006 zoned plans, the design of the project has been completed. The test results on GE01MB platform accord with GB13955-2005, Test efficiency than similar products.