Programmable logic controller文档格式.docx

Programmable logic controller文档格式.docx

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Withmoreandmoremanufacturersinvolvedinthecompany'

sproductionanddevelopment,PLCfunctionexpandrapidly,programminglanguagealsogreatrich,thisisthedevelopmentofeverynewthingmustgothroughtheprocess,alsovariousmanufacturerstendtodeveloptheirownladderlogiclanguage（foraPLCprogramminglanguage）.ThiscomplexPLClanguagecannotapplicabletoalltypesofequipment.However,withtheothercomputerlanguageslike,oncethisladderlanguagehasbeenwidelyused,thenthelanguagebeingusedinmostoftheequipmentonthepossibilityisbig,mostofthesystemdesignerswillfindproductionofaparticularmanufacturerofproductsforthewritingsystem.

Itshouldbenotedthattheprogrammablelogiccontrollerisoftenreferredtoas"

PLC"

or"

programmablecontroller"

.Althoughtheterm"

programmablelogiccontroller"

hasbeenwidelyaccepted,itisnotliketheabbreviation"

personalcomputer"

becausetheabbreviation"

usuallyreferstothepersonalcomputerused.InthisarticlewewillseethatPLCdoesnotmeanpersonalcomputer.

Canbeprogrammablecontrolleristhepersonalcomputerusersasfreemanyconfigurationoptions,aspersonalcomputersselectedwhichisbettersomecompletelyrelyontheirownexperience,asacontrollerofalotofsetupoptionstogoodcontrolitmadehimworkneedstorelyontheirownexperience.。

ModularPLCincludingthesystemcomponentsare:

1processor

Processor（sometimesreferredtoasCPU）isaprogramofthecentralprocessorcanexecute,whichisfullofthemodulewithanumberofspecificfeatures,thesefeaturessomeprocessingmorecomplexmathematicaloperationsandsomeofthePIDcontrolloopandprogrammablecommandprocessoriscomposedofamicroprocessor,asystemmemory,serialcommunicationportandprinter,PLCLANlinksandexternalprogrammingequipmentsystemthroughtheI/Oportsupply.

2Architecture

Generally,themetalframeandtheprintedcircuitboardareconnectedwiththePLCinputandoutputmoduleandtheprocessor,andthenumberofthemountingframesrequiredforthesystemisrealizedaccordingtothespecifiedmodule.Theassemblyframeprovidesdataandpowerthroughthemotherboardandthemoduleconnectionprocessor.Withoutpowersupplystructuretopreservethemodularpowersupply,theprocessorofthesystemisindependentlyinstalledandthecablerackareconnectedtogether,frameassemblycanismounteddirectlytothepanel,orcanbeinstalledinthestandardwidthof19andmultiplemountingframebetweenislinkedtoensurethatadapttothelargenumberofI/Omoduleinthewholesystem.

3inputandoutputmodules

Theinputandoutput（I/O）modulesareconnectedtoaparticularapplicationprogrambasedonthespecifiedinputandoutputsignals,whichcanbedividedintodiscretecategories,analoghigh-speedcountersorregistertypes.

DiscreteI/Omodulesaregenerallyableto8-bitor16bitdataprocessing,insomecases,switchinputandoutputmoduleisspecifiedasaninputoroutput,butmanufacturersgenerallyprovideafreeallocationofinputsandoutputscanbecuredwithinthesamemodule.

Analoginputandoutputmoduleisfeasibleandapplicabletotheexpectedresolutionandvoltageorcurrentrange,thesehavebecomethegeneraldiscreteinputoroutputmodule,somemanufacturersbetweenthesamemoduleprovidesanaloginputandoutput,tosimulatethePLCcanalsobeaccepteddirectlythermocoupletemperaturemeasurementandmonitoring.

PulseinputtoPLCcanbeacceptedusinghighspeedcountermodule.Thismodulecanbeusedtomeasurethefrequencyoftheinputsignalfromthetachometerorfrequencygenerator.Thesemodulescanalsocounttheincomingpulsesifrequired.Ingeneral,boththefrequencyandcountofthesamemodule,ifbotharerequiredintheapplication.

Theregisterinputandoutputmodulestransmitinformationfrom16or8bits,andfromaprogrammablecontroller.Thesewordsareusuallynumbers（BCDcodeorbinary）whicharetheinputdatafromtheencoderswitchorencodersystemtobegeneratedbythePLCoutputdisplaydevice

4,powersupply

Thespecifiedpowerdependsonthemanufacturer'

sprogrammablecontrollerusedintheapplication.Asmentionedabove,insomecases,thepowersupplytoprovidetherequiredpowerofthesystemasapartoftheprocessormodule.Ifthepowersupplyisaseparatemodule,itmustbeabletoprovideagreatercapacitythanthesumofallthecurrentsneededfortheothermodules.Fortheinternalprocessormoduleofpowersupplysystem,mayhavesomemodules,inthesystem,muchpower,ratherthanfromtheprocessor,becausevoltageorcurrentrequirements,onlythroughtheadditionofapowersupply.Thisisgenerallytrueiftheanalogorexternalcommunicationmodule,astheserequirementsoftheDCpowersupply,inthecaseoftheanalogmodule,mustbewellregulated.

5,programmingunit

Theprogrammingunitallowstheengineerortechnicalpersonneltoenterandedittheprogramexecution.Initssimplestform,itcanbeahandhelddevicethatshowsthestepsorfunctionsoftheinputanddisplaydevices（lightemittingdiodesorliquidcrystaldisplays）tothekeyboardinputprogram,asshowninfig..Moreadvancedsystemsuseasinglepersonalcomputer,whichallowsprogrammerstowrite,view,edit,anddownloadtheprogramintoaprogrammablecontroller.Thisisachievedbythemanufacturerwithproprietarysoftwareavailablefromtheprogrammablecontroller.Thesoftwarealsoallowstheprogrammerorengineertomonitortheprogramasitisrunningtheprogram.Withthismonitoringsystem,suchasinternalcoils,registers,timersandotheritemsthatarenotvisibleexternallycanbemonitoredtodeterminethecorrectoperation.Inaddition,theinternalregisterdatacanbechanged,ifrequiredtofinetunetheprogramoperation.Thismaybeadvantageouswhendebuggingaprogram.Communicationwiththesystem'

sprogrammablecontrollerisacableconnectedtoaparticularprogrammingportonthecontroller.Connectedtopersonalcomputerscanbeinstalledthroughaserialportorfromaspecialcard.

Programmablecontrollerisakindofspecialcomputer.Becauseitisacomputer,ithasallthebasiccomponentsofacomputer,acentralprocessingunit,memory,inputinterfaceandoutputinterface.Thecentralprocessingunit（CPU）isanimportantpartofprogrammablelogiccontroller（PLC）control.Itcanexplainthesameproceduresandcommandsdirectlyfrommemoryandbehaviortothosecommands.Thisunitinthecurrentprogrammablelogiccontroller（PLC）isamicroprocessorbasedsystem.Processormoduleofcentralprocessingunit（CPU）insystemmodule.

Memorysystemsareusuallyoftwotypes,read-onlymemoryandrandomaccessmemory.ROM'

smemorycontainsprograminformationthatallowsthecentralprocessortointerpretandactontheladderlogicprogramstoredintheRAMstore.RAMstorageisusuallyremovedinordernottolosethepoweroftheladderprogrammingsystem.Thebatterycanbeastandardtypeofdrybatterycharge.Nowtheprogrammablecontroller（PLC）unitwithelectricallyprogrammable