The Communication Cable Fault Detection System

Communication Cable is used for audio communications and high-frequency carrier long-distance digital communications and signal transmission cables,and widely used in all sectors. Due to various reasons, communication cables are susceptible to short-circuit, and other fault breaks. Rapid and accurate detection of communications cable fault, which reduce the fault, is a very important study.This paper starts with some analysis of the causes of the communications cable fault, introduces the communications cable fault classifications, and then elaborates on the classic method of communication cable fault detection methods and new abroad detection methods. It focuses on describing a high-precision detection technology TFDR and a live-ware detection technology SSTDR. Then SSTDR and TFDR are made to a combination of new detection method to improve existing method performance.Communication cable network line management and automatic fault diagnosis can improve the reliability of signal cable, reduce the cable fault of the manual workload of the investigation, and improve the operation of the cables automation. This paper describes the design of the detection system whose hardware platform can achieve a variety of communication cable fault detection method. The system used DSP and CPLD circuit as a core module, using DDS chip to occurred arbitrary waveforms. A new high-speed AD chip is used for sampling. PC and RS485 using detection systems and other communications can be formed distributed detection network. The system used the SSTDR detection technology to achieve a real-time online testing and predict the occurrence of low resistance short-circuit faults, and used the TFDR detection technology to detect the faulted line cable fault type and precise location。The main works of this thesis are in-depth analysis of communications cable detecting technology at home , abroad and developments, the new detection methods, the system design and device selection; studying DSP,CPLD, high-speed ADC chip MAX1198,DDS chip AD9851 and the structural characteristics of the external device in depth and designing of the system hardware schematic diagram and the hardware circuit board production; Completing in Quartus II development environment based on the Verilog HDL CPLD Design Software; developing in the context of the development of DSP software design in CCS2.0; finally, debugging the hardware and software and got the expected results.