【正文】 strong antiinterference, design and missioning period shorter, more people to pay attention to such advantages as etc, and has bee a current in the elevator control system used in most control mode, now also widely used in traditional relay control system technical reformation. Keywords: PLC of elevator control system elevator system overhaul and debugging 武漢職業(yè)技術(shù)學(xué)院 目錄 摘 要 .................................................................... 1 1 PLC 的發(fā)展歷程 ........................................................... 1 早期的 PLC（ 60 年代末 — 70年代中期） ................................................... 1 中期的 PLC（ 70 年代中期 — 80 年代中后期） ............................................ 1 近期的 PLC（ 80 年代中后期至今） ........................................................... 2 PLC 的應(yīng)用領(lǐng)域 .................................................................................................................................. 3 開(kāi)關(guān)量的邏輯控制 ..................................................................................... 3 模擬量控制 ............................................................................................... 3 運(yùn)動(dòng)控制 ................................................................................................... 3 過(guò)程控制 ................................................................................................... 3 數(shù)據(jù)處理 ................................................................................................... 3 通信及聯(lián)網(wǎng) ............................................................................................... 4 2 PLC 的基本結(jié)構(gòu) ........................................................... 4 中央處理單元 (CPU) ........................................................................................................................... 4 CPU的構(gòu)成 ................................................................................................ 4 CPU的工作機(jī)制 ......................................................................................... 4 存儲(chǔ)器 .................................................................................................................................................. 5 I/O 模塊 ................................................................................................................................................. 5 輸入接口 ................................................................................................... 5 發(fā)光二級(jí)管 ............................................................................................... 5 光電三級(jí)管 ............................................................................................... 5 輸出接口 ................................................................................................... 5 輸出接口電路工作過(guò)程： .......................................................................... 6 輸入接口電路工作過(guò)程： .......................................................................... 6 常用的 I/O 分類： ..................................................................................... 6 電源 ...................................................................................................................................................... 6 底板或機(jī)架 .......................................................................................................................................... 6 PLC 系統(tǒng)的其它設(shè)備 .......................................................................................................................... 7 編程設(shè)備： ............................................................................................... 7 人機(jī)界面： ............................................................................................... 7 3 PLC 的基本設(shè)計(jì)原則和選型 ................................................. 7 PLC 控制系統(tǒng)的設(shè) 計(jì)基本原則 ......................................................................................................... 7 最大限度地滿足被控對(duì)象的控制要求 ......................................................... 7 保證 PLC控制系統(tǒng)安全可靠 ...................................................................... 8 力求簡(jiǎn)單、經(jīng)濟(jì)、使用及維修方便 ............................................................ 8 適應(yīng)發(fā)展的需要 ........................................................................................ 8 PLC 的選型 .......................................................................................................................................... 8 輸入輸出（ I/O）點(diǎn)數(shù)的估算 ...................................................................... 8 存儲(chǔ)器容量的估算 ..................................................................................... 9 控制功能的選擇 ...........................