一、存储程序电子交换系统自从自动交换机代替人工方式交换以来,经历了步进式交换机、纵横式交换机、电子交换机,而进入了目前最先进的存储程序控制式交换机(简称程控交换机)。从控制方式上说,交换机可分为布线逻辑控制式和存储程序控制式两类。所谓布线逻辑方式,是指所要进行的控制是由事先布置好的线路逻辑关系所决定的;而存储程序控制方式,其控制是由存入存储器的程序内容所决定的。程控交换以前所有各种交换机,都属于布线逻辑控制式的。当它要改变控制关系时,例如要变更服务业务,就得更改原已装好的线路关系。早期的电子交换机,全都是布控方式的。由于电子器件具有速度快的特点,遂可把计 First, the stored procedure Electronic exchange system since the automatic exchange instead of manual exchange, has gone through step-by-step switches, vertical and horizontal switches, electronic switches, and entered the most advanced storage program-controlled switches (referred to as program-controlled switches). From the control mode, the switch can be divided into wiring logic control and stored program control two types. The so-called wiring logic means that the control to be carried out is determined by the logical relationship of the laid-out circuits in advance; and the control of the storage program is controlled by the contents of the program stored in the memory. Program-controlled switching All previous switches, all belong to the wiring logic control. When it wants to change the control relationship, for example, to change service business, you have to change the original installed line relationship. Early electronic switches, all controlled by the way. Due to the characteristics of electronic devices with fast, then the meter can be