在铁路程控电话交换网的发展过程中，各级枢纽及站段、端站的程控化进程往往是逐步实施的。在局部程控化以后，如何迅速发挥其网络优势，使原有的“点对点”长途自动电路能够进网交换，是程控发展过程中存在的普遍性问题。改造原CZ型长途自动接续机，使之能够与程控交换机实现 In the process of developing the program-controlled telephone exchange network of railway, the process of program-oriented control of terminals and stations at all levels and end stations are often implemented step by step. After local programmable control, how to rapidly exert its network advantage and enable the original “point-to-point” long-distance automatic circuit to exchange network is a universal problem existing in the development of programmable control. Transformation of the original CZ long-distance automatic connection machine, so that it can be achieved with the program-controlled switches