可编程控制器（PLC）在1000t挤压机控制中的应用

1000t挤压机是生产石墨电极（炼钢用）的主要设备，系统较庞大，工序较复杂，用常规控制较难实现，采用了PLC进行控制，实现了系统自动、手动控制功能。系统共有38点入，33点出，还有2路压力信号（模拟量）需要采集，采用了三菱公司FX2系列PLC，48点基本单元FX2-48MR，48点扩展单元FX2-48ER，还有一块模拟模块FX-4AD。由于系统工艺的复杂性、工艺的特殊性，在控制软件的编制上并没有统一采用梯形图编程法，而是采用梯形图编程法与状态转移图编程法相结合的方法，这样大大提高了软件的可编性、可调性、可读性。

Application of Programmable Logical Controller (PLC)in the Control of 1 000 Ton Extruder

The 1 000 ton's extruder is a piece of main equipment to produce graphite electrode. It is a bigger system, its working procedure is very complicated , and it is difficult to be controlled by conventional control method, thus the PLC has been used to control the extruder and both automatic and manual control have been implemented. There are 38 inputs, 33 outputs and two analog signals in the system. PLC in FX2 series of MITSUBISH was adopted : basic unit FX2-48MR,extend unit FX2-48ER, and analog module FX-4AD. Because of process complexity and speciality, a mixture method of ladder chart and state transfer chart has been explored to program. This method makes the program programmable, adjustable and readable.