针对窄脉冲时域反射法存在的"测试盲区"问题,结合网络传输信号无地差分的特性,提出了一种采用宽脉冲差分探测信号的线缆测试方法。该方法可以测试网络线缆的长度,判断故障的类别,并很好地解决了"测试盲区"问题。该文在介绍该方法的基础上,提出了使用该方法设计的网络线缆测试仪的硬件结构,并对其中的脉冲产生与回波处理模块进行了详细的分析。最后,给出了使用该测试仪进行网络线缆测试的实验结果,并对结果进行了分析。结果表明,该方法稳定可靠,具有实用价值。
Time domain reflection is a method for detecting cable's fault positions and reasons by analyzing the relationship between the transmitted pulse and the reflected pulse. Aimed at the blind spot in the domain reflection with narrow transmitted pulse, a method using wide differential transmitted pulse is proposed. The cable length and the fault reasons can be located by the method and the blind spot can be eliminated. The hardware structure of network cable tester designed by the method is presented and the key parts pulse generator and reflected pulse analyzer are analyzed in detail. At the end, the experiment data obtained by network cable tester are analyzed, the results show that the method is reliable.