1.历史的回顾早期传统的工业生产过程控制大都采用模拟式仪表。后来出现了数字仪表,如数字式调节器,变送器和执行器等。早在50年代,国外就在工业控制中应用了计算机,国内则从60年代中期开始,也开展了用于工业 1. Historical Review Early traditional industrial process control mostly used analog instrumentation. Later appeared digital instruments, such as digital regulators, transmitters and actuators. As early as the 1950s, foreign countries used computers in industrial control, while domestic ones started in the mid-1960s. They also started to use computers for industrial