This paper firstly introduces the meaning of subjects ; summarize the development of plc technology and ac frequency conversion for speed adjustment . in the second chapter , we illustrate the structure and flowchart of plc , then we introduce characteristic of mitsubishi fx2n plc . in the third chapter , we focused on the structure of transducer arithmetic of controlling , basic principle and the advantage of ac frequency conversion for speed adjustment . in the forth chapter , we emphasized on the structure of this system , the configuration of hardware and the implement of software in this system . in the fifth chapter , we introduce the anti - jamming measure that the system adopted . in the last chapter , we summaries the article 基于fx2nplc的編程軟件gxdeveloper7 . 0采用模塊化的程序設(shè)計(jì)方法,大量采用代碼重用,減少軟件的開(kāi)發(fā)和維護(hù)。本文首先介紹了課題的意義, plc技術(shù)、變頻調(diào)速技術(shù)的發(fā)展概況。第二章詳細(xì)的介紹了可編程序控制的基本構(gòu)成和數(shù)據(jù)處理流程,然后詳細(xì)的介紹三菱fx2nplc的特點(diǎn)。