毕业设计-自动售货机的PLC控制

第1页共33页常州机电职业技术学院毕业设计（论文）作者：王义学号：40911235系部：电气工程系专业：自动化（电气的运行与控制）题目：自动售货机的PLC控制指导者：陈小艳评阅者：第2页共33页目录摘要................................................................................................................................4绪论................................................................61.1自动售货机设计目的和意义..................................61.2自动售货机的发展历史和前景................................71.3自动售货机的PLC控制设计原理..............................81.4自动售货机设计的基本思路......................................................................9第2章PLC的概述...................................................................................................102.1PLC的定义................................................................................................102.2PLC的简介................................................................................................102.3PLC的工作原理........................................................................................102.4PLC的循环扫描工作.................................................................................112.5PLC的编程语言........................................................................................122.6PLC的特点................................................................................................122.7PLC的硬件组成..........................................................................................13第3章自动售货机PLC控制设计方案研究..........................................................153.1工控机自动售货控制系统.........................................................................151）机箱采用钢结构，有较高的防磁、防尘、防冲击的能力。.................152）机箱内有专用底板，底板上又IPC和ISA插槽。................................153）机箱内有专门电源，电源有较强的抗干扰能力。.................................154）要求具有长时间工作能力。.....................................................................153.2PLC自动售货控制系统............................................................................153.3自动售货机设计的基本思路....................................................................163.4自动售货机设计的主要内容....................................................................16第3页共33页第4章自动售货机PLC控制（系统）设计............................................................174.1PLC各I/O地址分配................................................................................174.2什么是梯形图（LAD）..............................................................................194.3投入货币累加显示电路.............................................................................194.4自动售货机设计的梯形图........................................................................214.5MCGS组态程序设计说明..........................................................................284.6调试结果、调试中出现的问题及解决方法............................................29结论..............................................................................................................................31致谢..............................................................................................................................32参考文献.....................................................................................................................33第4页共33页摘要本文主要介绍了自动售货机的基本原理以及工作流程，然后以一次交易过程为例，把交易过程分为几个程序块，然后分别对程序块进行编程。具体的说明了可编程控制器在自动售货机中的作用。在接收到货币已输入的前提下，靠触摸或者控制按钮输入信号使控制器启动相关位置的机械装置完成规定动作，将货物输出。自动售货机是台机电一体化的自动化装置，再接收到货币已输入的前提下，靠触摸控制按钮输入信号使控制器启动相关位置的机械装置完成规定动作，将货物输出。当顾客按下需要买的商品所对应的按键时，数码管上显示出该商品的的价格，然后顾客需要将货币投入投币口，数码管上显示出所投币额。当按下确认键，则自动售货机将对投入的货币与商品的价格进行比较。如果投入的币额足够时，则自动送出商品，并且把多余的钱找回，在数码管上显示出来。如果两者币的相等，则直接送出商品。如果投入的币额不足时。则报警，报警时间3秒。当顾客一旦按下确认键3秒后，自动售货机将自动恢复到初始状态，此时顾客才可以进行下一次购货操作。本次设计用到了以前学过的PLC编程设计，参考了电子电路的设计方法关键字：自动售货机PLC编程第5页共33页AbstractThispaperdescribesthebasicprincipleofautomaticvendingmachinesandworkprocesses,andthenacourseofdealing,forexample,thetransactionprocessisdividedintoseveralblocks,andthenprogramtheblockrespectively.Specificinstructionsoftheprogrammablecontroller'sroleinthevendingmachines.Receivingthemoneyhasbeenenteredunderthepremiseofcontrolbuttonsorbytouchingtheinputsignaltothecontrollerstartsthelocationofthemechanicaldevicesrelatedtocompletetheaction,thegoodsoutput.Vendingmachinesareelectromechanicalintegration,automationdevices,stopreceivingmoneyunderthepremisehasbeenentered,bytouchingthecontrolbuttoninputsignaltothecontrollerstartsthelocationofmechanicalequipmentrelatedtocompletetheaction,thegoodsoutput.Whencustomersneedtobuyaproductwhenitpressedthecorrespondingkey,theLEDdisplayonthepriceofthegoods,thenthecustomerwillneedtoinvestmoneyslot,thedigitaldisplayontheamountofthecoin.WhenyoupresstheEnterkey,thenthevendingmachinewillbeputintothecurrencyandcommoditypriceswerecompared.Iftheamountinvestedenoughmoney,thenautomaticallysendgoods,andtheextramoneyback,inthedigitaltubedisplay.Ifthetwocurrenciesareequal,thensendgoodsdirectly.Iftheamountofmoneyinvestedislessthanthealarmtime,alarmtime,3seconds.WhencustomerspresstheEnterkeyoncefor3seconds,vendingmachineswillautomaticallyreverttotheinitialstate,thenthecustomercanpurchasethenextoperation.ThisdesignusesapreviouslylearnedPLCprogrammingdesign,referencedesignofelectroniccircuits.Keywords:vendingmachinePLCProgram