脉冲编码调制被广泛地应用于光缆、微波与卫星等数字通信系统中。现有的PCM终端机在工作状态下很难对各话路的编译码器与话路滤波器进行在线故障检测,通常只能进行停机检测,这样就要中断正常的通信业务,同时一般整机故障只有声、光告警指示,不能自动进行准确记录。因此,在新一代的PCM终端机中,采用了微机技术,使其能够在通信系统 Pulse code modulation is widely used in optical cable, microwave and satellite digital communications systems. Existing PCM terminals in the working state is very difficult for each channel of the codec and speech filter for online fault detection, usually only downtime detection, so we must interrupt the normal communication services, while the general machine Fault only sound, light alarm instructions, can not be accurately recorded. Therefore, in a new generation of PCM terminals, the use of microcomputer technology to enable it to communicate in the system