一、前言 NEAX61-E程控交换机在投入正常使用之前,必须对系统进行一系列调测工作,检测交换系统的功能是否完备,同时解决出现的各种问题和故障,使整个系统处于良好的工作状态。在工程调测过程中,经常会遇到各种问题,其中最常见的就是LTC台（Line Test Console-用户测量台）的故障。其原因主要有以下几个方面: I. Preface NEAX61-E program-controlled switches in the normal use before the system must be a series of commissioning work to detect the function of the switching system is complete, and solve the problems and failures that occur, so that the entire system is in good working condition . During engineering commissioning, various problems are often encountered. The most common of these is the failure of the Line Test Console (LTC Station). The reasons are mainly the following aspects: