【正文】 munications． At the present， PLC has bee the most important automatic equipment and been applied widely ,The degree and extent of PLC development are the symbols of automatic level in one country． The main body of a book has been designed specifically for the relay controlling system reliability defects such as relatively poor， using lack to go to the lavatory nimbly， making use of PLC to be in progress， has reached the purpose controlling the mail sorting． PLC is in frequency transformer in fully utilizing in system， use the varying voltage exchanging frequency conversion to drag moving a technology ,the starting having realized reliably， the malfunction leads the low function． This paper first introduces the background related to it and the meaning and source of this title， the definition of systematic scheme， overall position and design thought and theoretical basis； then carries out detailed design of the system which includes control circuit hardware and assembly； Software design and a ladder diagram； System munication by and debugging and so on． In the master system design， Configuration software is used to build dynamic operation pictures with Windows style， such as parameter setting frame，process monitor frame， data processing frame， fault location and system animation， etc． Finally ,a conclusion is given ． Keywords： PLC controls ； Sorting mail； Touch screen 北華大學(xué)畢業(yè)設(shè)計(jì)（論文） 1 目 錄 摘 要 ........................................................................................................................ 1 Abstract ........................................................................................................................... 2 1 緒論 ............................................................................................................................ 1 課題的研究背景及意義 .................................................................................... 1 PLC的概述 ........................................................................................................ 1 PLC的產(chǎn)生背景 ...................................................................................... 1 PLC的發(fā)展過(guò)程 ...................................................................................... 2 PLC的特點(diǎn) .............................................................................................. 3 PLC控制系統(tǒng)程序設(shè)計(jì)的步驟 ......................................................................... 4 2 郵件自動(dòng)分揀系統(tǒng) ..................................................................................................... 5 自動(dòng)分揀系統(tǒng)概述 ........................................................................................... 6 自動(dòng)分揀系統(tǒng)的主要特點(diǎn) ................................................................................ 6 郵件分揀系統(tǒng) PLC控制硬件部分 .................................................................... 8 PLC 控制范圍及要求： .......................................................................... 8 分揀機(jī)的動(dòng)作過(guò)程 .................................................................................. 8 機(jī)型的選擇及輸入輸出的確定 ........................................................................ 9 內(nèi)存估計(jì) ................................................................................................. 9 響應(yīng)時(shí)間 ................................................................................................. 9 輸入輸出的確定 ..................................................................................... 9 3 PLC 控制程序 ........................................................................................................... 12 梯形圖程序 ..................................................................................................... 14 程序圖中各輔助觸點(diǎn)的作用 .......................................................................... 20 程序圖中各個(gè)定時(shí)器的作用 .......................................................................... 21 4 安裝與調(diào)試 ............................................................................................................... 22 安裝可靠性技術(shù)要求 ...................................................................................... 22 PLC程序的調(diào)試運(yùn)行 ...................................................................................... 24 北華大學(xué)畢業(yè)設(shè)計(jì)（論文） 2 5 觸控屏技術(shù)介紹 ....................................................................................................... 24 電容式觸控屏 ................................................................................................. 24 電容式觸控屏簡(jiǎn)介 ................................................................................ 24 電容式觸控屏工作原理 ........................................................................ 24 電阻式觸控屏 ................................................................................................. 25 電阻式觸控屏簡(jiǎn)介 ................................................................................ 25 電阻式觸控屏工作原理 ........................................................................ 25 觸控屏人機(jī)界面的特點(diǎn) .................................................................................. 25 觸控屏人機(jī)界面的功能 .................................................................................. 26 6 檢測(cè)單元觸控屏編程 ............................................................................................... 27 觸控屏程序的建立 ..................................................