一、问题的提出一位微处理机(简称一位机)自问世以来,由于具有系统构成简单、程序可编、抗干扰性强、工作可靠以及特别适用逻辑开关量运算等一系列特点,而受到国内工业界的普遍关注。近年来,一位机在国内的研制、应用已初具规模,在工业控制领域取得了可喜的成绩。但随着大规模集成电路和微机技术在工业控制领域的迅速发展,人们的注意力已开始转向国外可编程序控制器(简称 PC机)的引进、应用方面上,对一位机的 First, the issue raised A microprocessor (referred to as a machine) since its inception, due to its simple system, programmable, strong anti-interference, reliable and particularly suitable for a series of features such as logic switching operations, and By the domestic industry’s widespread concern. In recent years, a machine in the domestic research and application has begun to take shape, in the field of industrial control has made gratifying achievements. However, with the rapid development of large-scale integrated circuits and micro-computer technology in the field of industrial control, people’s attention has begun to turn to the introduction of foreign programmable controllers (PC machines for short). On the application side,