从这几年国内外大型工程自动控制系统的组成来看,采用集散控制系统和可编程序控制器(PC)的混合型方案已经成为一种趋势。同时,可编程序控制器已在“机-电-仪”一体化中和在工厂自动化中,形成了主导地位.因此,自从一九六九年美国数字设备公司(DEC)研制出世界上第一台可编程序控制器,并首先在通用汽车公司应用获得成功以后,西德、日本、英国、法国、瑞典等国相继开发了各类可编程序控制器,目前已经系列化,成为自动化系统的基本控制装 From the composition of large-scale engineering automatic control systems at home and abroad in recent years, it has become a trend to adopt a hybrid solution that uses a distributed control system and a programmable logic controller (PC). At the same time, PLCs have become dominant in “machine-to-meter” integration and in factory automation, and as a result, since 1961, Digital Equipment Corporation of America (DEC) A programmable logic controller and, first of all, after the success of GM’s application, various programmable logic controllers have been developed in West Germany, Japan, the United Kingdom, France, Sweden and other countries and have been serialized to become an automation system The basic control equipment