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一、PC的变迁 PC(Programmable Controller),1969年诞生以来取得了飞速地发展.直到现在,发展过程大致分为三个阶段. 第一个阶段是使用晶体管或逻辑集成电路(IC)作为专用电路构成的,I/o点数为几百点的规模,以位处理功能为基础.因此这时称为PC或PLC(Programmble logic Contrller),专门用来代替继电器控制盘.从本质上讲,就是继电器控制盘的代替器.该商品的特点是灵活性好(容易更改程序)、小型、轻量等.它是从汽车产业开始,逐渐渗透到钢铁、化学、
First, the PC changes PC (Programmable Controller), has achieved rapid development since its birth in 1969. Until now, the development process can be divided into three stages.The first stage is the use of transistors or logic integrated circuits (ICs) as a dedicated circuit Constitute, I / o points for the size of a few hundred points to bit processing functions based on the so called PC or PLC (Programmble logicContrller), designed to replace the relay control panel.In essence, is the relay Control panel replacement device.The product is characterized by good flexibility (easy to change the program), small, lightweight, etc. It is from the automotive industry began to gradually penetrate to the steel, chemical,