Development Of Distributed Multi-core Cables Tester

Intricate internal cable networks of large equipment, such as aircraft, ships, etc. arecharacterized in points and difficulty to disassemble. Using a commercially centralizedcable test equipment to detect them requires long adapter cable, which is not only bulky,heavy but also wiring tedious as well as such problems error-prone, expensive and easybeing damaged due to frequent drag, affecting the accuracy of the test results. Inaddition, these equipments are inconvenient to utilize in some occasions such asexternal field testing.In response to these problems, the subject developed a CAN bus based distributedmulti-core cable tester. The tester achieve a capacity of up to160test points in a19-inch1U portable chassis, not only for structural scan, continuity testing, insulationtesting representative test items, but also increased the vibration test function used todetect connection reliability of cable and connector. This equipment requires only acommon measurement lines and a short adapter cable leading to improvement of testefficiency and accuracy.On the hardware part, equipped with DSP2812as the host CPU, overvoltageprotection circuit design and in accordance with standard drawing board ensuring testersafe, relay matrix switch designed for fast switching test channel, the tester utilize itseCAN modules and high-speed on-chip A/D module to implement CAN buscommunication and signal acquisition. On the software part, using self-developed"command number+parameter" format CAN-bus communication protocol as a guide,the tester is firstly designed the testing process and master-slave on-line testingmechanism, following by writing DSP firmware in CCS3.3environment to achievetester’s CAN bus communication functions and test process control functions and thendeveloped driver in VC.60environment, achieving the management host access andcontrol tester. On the structure part, control panel, relay array panel and functionindicator panel independent from each other, under the guide of modularization thinking.Through the rational design of circuit board structure and inter-board connection, thestructure of the cable tester standardized and miniaturized, portability andmaintainability being greatly improved compared to similar products.Unite debugging results in the laboratory show that various functions and technicalindicators of this project, a distributed multi-core cable tester, meet the design requirements and performance stability.