程控数字交换技术程控(存储程序控制)数字电话交换机,是由微电子技术与数字技术相结合组成的一种新型电信交换系统。七十年代许多国家都在研制这种交换机,目前已有十几种程式投入使用。一九八○年,各国已使用的程控数字电话交换机为一千五百万门,年增长率为百分之一百二十七点五。这种交换机有许多新的功能(如缩位拨号、呼叫转移、会议 Program-controlled digital switching technology program-controlled (stored program control) digital telephone switches, is a combination of microelectronics and digital technology, a new type of telecommunications switching system. Many countries in the 1970s are developing this switch, there are already a dozen programs put into use. In 1980, the number of programmed digital telephone exchanges in various countries was 15 million, representing an annual growth rate of 127.5%. This switch has many new features (such as speed dials, call forwarding, conferencing