Design Of Communication Cable Fault Detector

Communication Cable is a kind of cable used for short-range audio communication, distant range radio-frequency carrier digital communication and signal transmission. It is widely applied into many important domains such as communication, instrument, electrical power and so on. Due to several factors can cause a short circuit, disconnection and other failures to communication cable.Therefore, how to detect quickly and accurately to reduce the down time after the errors to communication cable happened and how to work to improve the stability of communication cable is an important research in current area of LOC. This paper described how the error to communication cable occurred firstly, and then presented the classification of defects to communication cable. This paper also analyzed the status and development at home and abroad of communication cable's detection technology deeply, and introduced the classic detection methods and new detection methods abroad of communication cable fault detection. The design is based on the principle of time-frequency domain research (TFDR), and used Wigner time-frequency distribution and cross-correlation detection to process transmitted signals and reflected signals. We used the system on a programmable chip (SOPC) to design a new type of communications cable fault detectors. Given system design specifications and overall design, we completed the overall design of the system. For the part of imitation, we used DDS chip to generate sine wave as the transmit, then designed signal transmit circuit and reasonable signal conditioning circuit;at the same time, we used the new kind of high-speed ADC to sample the reflected signal, and designed signal receiving circuit and reasonable signal conditioning circuit. For the digital part, this design is mean to construct the SOPC system in the FPGA, embedded Nios II soft-core processor to control the operation of the entire system. We selected Altera Corporation's Cyclone II series FPGA chip EP2C8, and built a peripheral configuration circuit. In the Quartus II EDA software development environment for FPGA designing and using, we finished the top-level module design to achieve complete system configurationThe design is based on the implementation methods of hardware SOPC, combined with TFDR detection theory. It can produce a good detecting transmission waveforms and also can collect the good reflected signal .Communication cable can quickly and accurately detect the point of failure and achieve communication cable fault location and type of judge. It has harmonious characteristics of portable and low cost, and enable to complete the fault detection .This paper has a clear content, and face to the practice of the project, and also has a utility value.