近年来,市内电话建设加快,大容量的市内电话局增多,使得对外线维护测试自动化的要求更为迫切。对于外线绝缘不良(对地、对电源负极、线间)和断线的自动测试,自动记录已经实现。但是,对于外线混连故障(一般称混线)的自动测试,即涉及到自动鉴别用户摘机和外线混连的问题,至今并未解决。国内曾经有文献[1]提到能“自动测试用户摘机或外线混连”,为此,我们走访了有关单位,进行了技术交流,并在理论分析及计算的基础上进行了一些实验研究,现将情况简介如下 In recent years, the rapid development of the city’s telephones and the increase of the large-capacity local telephone offices have made it more urgent to automate the testing of external lines. Automated logging has been implemented for automated testing of poor insulation of the outside line (to ground, to the negative pole of the power supply, to the line) and to disconnection. However, the automatic test for the external mixed fault (commonly referred to as the mixed line), which involves automatically identifying the user to pick up and connect the outside line, has not been solved so far. In the past, there were literature [1] mentioned that it could “automatically test the user to pick up the phone or connect with the outside line.” To this end, we visited the relevant organizations and conducted technical exchanges. Based on the theoretical analysis and calculation, some experimental studies Now the situation is as follows