基于PLC小型气象站设计(完整版)

洛阳理工学院毕业设计（论文）I基于PLC小型气象站设计摘要本论文着重介绍了以西门子公司生产的S7-200系列的PLC为主要控制元件，实现对外部环境的风速、大气压、温度和湿度进行实时监测和显示，以及当某项或多项空气指数超出设定的范围时系统会作出报警以警示人们当前环境对人某方面的危害；当这四种空气指数都符合舒适度的设定时，系统会输出显示为舒适。以上这些功能都是我们通过对PLC的编程实现的。本设计采用多种传感器，包括温湿度传感器、风速传感器以及大气压力传感器。这些传感器具有反应速度快、测量精度高、耗能低、自身功能强大和价格低廉等优点。当外部传感器监测到外部环境所对应的空气指数后通过变送器将电阻电流信号转换成标准模拟信号输入到模拟量输入扩展模块，然后输入模块通过计算和处理这些数据传输到CPU中，并储存在内部寄存器中；最后系统通过以太网模块的传输将测得的温湿度、风速和大气压传到上位机得到显示，当数值超过限定范围时会做出相应的报警。本设计的小型气象站的测量精度非常高，实时性也比较高，所以完全可以应用到日常生活中去。关键词：PLC，编程，传感器，显示洛阳理工学院毕业设计（论文）IIBasedonPLCsmallstationdesignABSTRACTThispaperintroducestheSiemensS7-200seriesPLCasthemaincontrolcomponents,realizetheexternalenvironmentofwindspeed,atmosphericpressure,temperatureandhumidityforreal-timemonitoringanddisplay,andwhenoneormoreoftheairindexwasbeyondthescopeofsettingthesystemwillalarmtowarnpeopleaboutthedangersofthecurrentenvironmentofacertainaspect;Whenthefourairindexmeetthecomfortsetting,systemwilldisplaytheoutputforcomfort.ThesefunctionsarebasedonPLCprogramming.ThisdesignUSESavarietyofsensors,includingtemperatureandhumidity,windspeedsensor,andtheatmosphericpressuresensor.Thesesensorshavereactionspeed,highprecision,lowconsumption,anditspowerfulfunctionsandthepriceislowwaitforanadvantage.Whenanexternalsensorstodetecttheexternalenvironmentoftheairindexafterthroughthetransmitterconvertsresistancecurrentsignalintostandardextensionmoduleanalogsignalinputtotheanaloginput,andtheninputmodulethroughcalculationandprocessingthesedatatotheCPU,andstoredintheinternalregister.FinallysystemthroughEthernetmoduleoftransmissionofthemeasuredtemperatureandhumidity,windspeedandatmosphericpressureisdisplayedtotheuppermachine,makesthecorrespondingalarmwhennumericalexceedsthelimits.Thedesignofsmallstationshashighmeasurementprecision,andhasahighrealtimecapability,soitcanbeappliedtodailylife.KEYWORDS:PLC，Programming，Thesensor，Display洛阳理工学院毕业设计（论文）III目录前言................................................................................................1第1章概述......................................................................................21.1本课题研究的意义...............................................................21.1.1国外发展历程.............................................................31.1.2国内发展历程.............................................................31.2小型气象站的应用情况.......................................................41.2.1在农业反面的应用.....................................................41.2.2在防灾和电力运输方面的运用..................................41.2.3本设计的应用.............................................................41.3研究的主要工作...................................................................5第2章控制方案...............................................................................62.1控制原理分析.......................................................................62.2控制要求...............................................................................7第3章设备的选型.............................................................................93.1传感器的选型.......................................................................93.1.1大气压力传感器.........................................................93.1.2风速传感器...............................................................103.1.3温湿度传感器...........................................................103.2PLC的选型.......................................................................113.2.1PLC的I/O点分析.....................................................113.2.2PLC扩展模块的选型................................................123.3设备清单.............................................................................133.4PLC的I/O接线图..............................................................14第4章软件设计.............................................................................164.1主程序流程图.....................................................................164.2程序梯形图.........................................................................174.2.1主程序.......................................................................174.2.2压力处理...................................................................18洛阳理工学院毕业设计（论文）IV4.2.3湿度处理...................................................................214.2.4风速处理...................................................................234.2.5温度处理...................................................................284.2.6舒适度判断...............................................................30第5章仿真....................................................................................315.1仿真软件的确定.................................................................315.2程序的仿真.........................................................................31结论..............................................................................................40谢辞................................................................................................41参考文献..........................................................................................42外文资料翻译..................................................................................44洛阳理工学院毕业设计