可編程控制器應(yīng)用中英文對照外文翻譯文獻

-PAGE1-中英文對照外文翻譯SupportsoftwareforthedevelopmentofprogrammablelogicIntroductionProgrammableLogicControllers(PLC)classofreal-timecomputersusedextensivelyinindustrialcontrolapplications.ThedevelopmentofaPLCapplicationrequirestheconfigurationoftheinputsandoutputsofthePLCarchitecture,thatistheselectionofthenumber,typeandaddressesoftheinputsandoutputsofthePLC,andthewritinganddebuggingoftheapplicationprogram.Programmingthesecomputersisusuallydoneinspecificgraphicalstructuredtextlanguages[Bekkum93,Hughes89,Jones83]andtheprogramdebuggingiscarriedoutinadevelopmentenvironment.Mostoftheavailableenvironments[SquareD90,Taylor90]allowprogramwritinginmorethanonelanguage,runningitbysteporinsegmentsontheactualPLCandcheckingwhethertheassumedlogicalrelationshipsbetweentheinputsandtheoutputsateachprogramsteporsegmentaresatisfied.Iaddition,theseenvironmentsofferengineeringsupport,suchasthepreparationofinput/outputwiringdiagramsandthegenerationoftheexecutablecodeoftheprogram.RecentversionsofcommerciallyavailableenvironmentsaresuppliedwithasoftwareemulatorofoneormorePLCunits.Thisallowstoperformprogramdebuggingwithouthavingaccesstotheprogrammablecontrolleritself.Also,theuseofemulatorsmakeseasierandeconomicallyaffordablethesimulationofalargenumberofprogramoperatingconditions.Bymakingsurethattheprogramoperatescorrectyunderallthecriticaloperatingconditions,theriskofimplementingaPLC-basedsystemthatdoesnotmeetthedesiredrequirementsisreduced.However,theultimategoalofadevelopmentenvironmentshouldbetoverifythefunctionalpropertiesandbehavioroftheprogramsinallthepossiblestatesthatthesprogramsandtheplantstheymayenter.Intheliterature,variouslanguagesandgraphicalormathematicalformalismsareproposedforwritingorspecifyingreal-timeprograms.Thetimingand/orfunctionalperformanceoftheseprogramscanbeverifiedatcompiletimeormathematically.ADA[Ada83],RT-ASLAN[Auemheimer86],EUCLID[Kligerman86],PEARL[Halang91],FLEX[Lin88]aresomeoftheproposedandmostwidelyknownlanguages.Theirgraphicalormathematicalformalismsarebasedontheuseoffinitestateautomata[Alford77],Petri-Nets[Fedler93],dataflowdiagrams[Zave82]andmetrictemporallogic[Koymans90].Althoughalltheseformalmethodsandlanguagesrepresentsignificantadvancestotheproblemofreal-timeprogramverification,stilltheyhavenotreachedthematurityrequiredtodealwiththecomplexitiesoflargesoftwaresystems.Untilthesemethodsreachacertainlevelofmaturitywemustrelyonlessformalmethods,tunedtotheneedsofspecificclassesofreal-timesystems.InthecaseofPLC,wemaycontinuetousesimulationasamethodtoreveallogicalerrorsinourprogramsandassesstheirbehaviorunderanincompletesetofpossibleprogramstates.Inaddition,wemayincludenewfacilitiesintheprogramdevelopmentenvironments,theuseofwhichwillreducetheprogrammingandengineeringeffortofanapplication.TheymaybeeditingandcompilationfacilitieswhichsupportapplicationprogramminginallthelanguagesdefinedintheIEC1131-3standard.Byusingtheselanguagesourprogrammingefficiencywillbeimprovedsignificantly,becauseeachoneofthemcanbeusedtoprogramthepartoftheapplicationforwhichitisappropriate,andyetthewholeapplicationcanbelinkedintoasingleexecutableprogram.Otherfacilitieswhichcanreduceengineeringeffortarethosewhichcanmakeeasierandmoremeaningfulthedeclarationoftheprograminputconditions.Thesefacilitieswillallowustostudyinagiventimingperiod,alargernumberofsimulationcasesthantheoneswemighthavestudiedwithoutthesefacilities.Furthermore,wemayexpandthescopeofthesimulationbyincludingasimulatoroftheplantwhichinteractswiththecomputer.Also,facilitiescanbeaddedtoassistinthebetterinterpretationofthegeneratedsimulationresults.Suchfacilitiesmayallowustoconfigurethedisplaysofthegenerateddatathewaywethinkappropriate,andanimatethesimulatedoperationoftheapplicationprogram.Inthispaperanarchitectureandlanguageconstructsareproposedforasoftwareaidwhich~anbeusedtodeclareinputconditionstoaPLCprogram,emulatethePLCoperationandconfigurethedisplayoftheemulationresults.Thecoreofthearchitectureisthevirtualmachine,whichisasoftwaremodulewhichemulatestheoperationofaprogramwrittenforaspecificPLCinanyapplicationprogramminglanguage.Thevirtualmachineislinkedwithexecutablecodegeneratedfromtwoothersoftwaremoduleswhichinterpretinstructionsdefiningtheinputconditionstotheapplicationprogramandtheconfigurationoftheoutputdisplay.Ofcourse,theproposedfacilitiesdonotsolvetheproblemofthecompleteverificationofthetimingbehaviorofanapplicationprogram.However,whentheyarecomparedwiththefacilitiesofferedbyvariouscommerciallyavailableaids,toouropiniontheydosignificantlyreducethetimetakentotesttheexecutionofaPLCprogramunderalargenumberofpossibleinputconditions,ondifferentarchitecturesandinterprettheresults.AscaleddownexperimentalimplementationoffacilitiesforaspecificPLCmodelisusedtodemonstratethefeasibilityoftheproposedconcepts.Theoperationoftheexperimentalset-uphasbeenvalidatedwithdatatakenfromtheexecutionofsampleprogramonaspecificPLC.PrinciplesofPLCOperation.TheProgrammableLogicControllerisaspecialpurposedigitalcomputerdesignedtocontrolmachineorprocessoperationsbymeansofastoredprogramandfeedbackfrominput/outputfielddevices.Itiscomposedprimarilyoftwobasicsections:theCentralProcessingUnit(PLC)andanInput/Output(I/O)interface.TheCPUencompassesallthenecessaryelementsthatformtheintelligenceofthesystem.ItisfurthersubdividedtotheProcessor,MemoryandPowersupply.TheCPUacceptsinputdatafromvariousinputfielddevices,executesthestoredprogramfromthememory,andsendsappropriatecommandstooutputfielddevices.TheInput/Outputsystemformstheinterfacebywhichthefielddevicesareconnectedtothecontroller.Itspurposeistoconditionthevarioussignalsreceivedfromorsenttofielddevices.ThroughthissystemtheCPUcansenseandmeasurephysicalquantitiesregardingamachineorprocess,suchasproximity,position,motion,leveltemperature,pressure,currentandvoltage.Basedonthestatussensedorvaluesmeasured,theCPU,throughthisinterfacesystem,issuescommandsthatcontrolvariousdevicessuchasvalves,motors,pumpsandalarms.ThemostcommontypeofI/Ointerfaceisthediscreteone.Thisinterfaceconnectsfieldinputoroutputdevices,whichprovideinputsignalsorreceivecommandsignalsoftheBooleantype.Pushbuttons,limitswitchesandselectorswitchesaresomeofthedevicesthatprovideincomingsignalsofthistype,,whereastypicalfielddevicesthatcanbeandpositionvalves.ThenumericalI/Ointerfaceisanothertypeofinterface,providedinaPLCsystem.Itcanallowreadingorwritingamulti-bitdigitaloranalogdevice.Multi-bitdeviceseithergenerateorreceiveagroupofbitswhichisthedigitalrepresentationofadecimalnumberorananaloguequantity.ThisgroupofbitsishandledasaunitbytheCPUandcanbeinparallelform(BCDinputsoroutputs)orinserialform(pulseinputsoroutputs).Typicalfielddevicesprovidingmulti-bitinputtoaPLCarethumbwheelswitches,barcodereadersandencoders,whereastypicaloutputdevicesareseven-segmentandintelligentdisplays.Theanaloguefielddevicesarethevarioussensors,motordrives,andprocessinstrumentsusedtomonitoraridcontrolphysicalvariablessuchastemperature,pressure,humidity,flow,etc.ThedeviceswhichmonitorphysicalvariablessendtotheI/OinterfaceanaloguevoltagesandcurrentswhichareconvertedbytheA/Dconverteroftheinterfacetoamulti-bitdigitalcode.Ontheotherhand,ananaloguedeviceusedtocontrolthevalueofaphysicalvariable,receivesfromtheinterfaceananaloguevoltageorcurrentasaresultofthedigitaltoanalogueconversionofdataproducedbytheCPU.TheprocessoroftheCPUperformsallthemathematicaloperations,datahandlinganddiagnosticroutinesbyexecutingacollection,storedinthememory.Thiscollectionconsistsofsupervisoryprograms,thatarepermanentlystoredinthememory,andapplicationprograms.Thesupervisoryprograms,knownastheexecutive,allowcommunicationwiththeprocessorviaaprogrammingdeviceorotherperipheralmemorymanagement,monitoringoffielddevices,hardwarefaultdiagnosisandexecutionoftheapplicationprogramwrittenbytheuser.ThememoryorganizationandthewaytheapplicationprogramisexecutedunderthecontroloftheexecutivearetwofeatureswhichdistinguishaPLCfromanyothergeneralpurposecomputer.Ingeneral,allPLChavememoryallocatedforexecutiveprograms,processorworkarea,datatableandapplicationprogram.TheprogrammedinstructionsandanydatathatwillbeutilizedbytheprocessortoperformitscontrolfunctionsarestoredintheApplicationProgramMemoryAreaandDataTableMemoryArearespectively.Thesetwoareascanbegroupedintowhatiscalledapplicationmemory.Eachcontrollerhasamaximumamountofapplicationmemorywhichispartofthetotalmemoryspecifiedforthecontroller.TheDataTableisfunctionallydividedIntotheInputTable,InternalStorageAreaandStorageRegistersArea.TheInputTableisanarrayofbitsthatstoresthestatusofthedigitalinputswhichareconnectedtotheI/Ointerfacesystem..TheOutputTableisanarrayofbitsthatcontrolthestatusofthedigitaloutputdevices,whicharealsoconnected.TotheI/Osystem.TheInternalStorageBitsAreaisthememoryareaallocatedforthestorageofthelogicstatusofflagsusedbytheapplicationprogram.TheStorageRegistersAreaisallocatedforthestorageofinputregisters,holdingregistersandoutputregisters.Theinputregistersareusedtostorenumericaldatareceivedviadigitalofanalogueinputinterfaces.Theholdingregistersareusedtostorevariablevaluesthataregeneratedbymath,timerandcounterinstructionsofaprogram.Theoutputregistersareusedtoprovidestoragefornumericaloranaloguevaluesthatcontrolvariousoutputdevices.EachvirtualmachineprogramisbuiltaccordingtoageneralcomputermodelapplicabletoanyPLCarchitecture.ThismodelmapstheusualfunctionsperformedbyaPLCtomachinelanguagefunctionsofasimplehypotheticalcomputer.Thiscomputerconsistsof:(a)aCentralProcessingUnit(CPU)(b)aMemoryunit(MU)wheretheapplicationprogramisstoredand(c)anumberofInputandOutputmodules(I/O)Atsystemstartup,theexecutionoftheexecutiveprogramisinitiated.Duringthisprogramexecution,theprocessorreadsalltheinputs,storestheirvaluesintheInputStorageAreaandrunstheapplicationprogram.TheresultswhicharegeneratedduringtheexecutionoftheapplicationprogramaresavedintheOutputStorageArea.Theprocessofreadingtheinputs,executingtheprogram,andupdatingtheoutdatealltheoutputsofthePLCbysuingthedataoftheOutputStorageArea.Theprocessofreadingtheinputs,executingtheprogram,andupdatingtheoutputsisknownasscan.Thetimerequiredtomakeasinglescaniscalledscantime.Afigurefortheworstcasetimeisusuallyprovidedbythemanufacturers.Generally,theyspecifythemaximumscan-timethatcorrespondstoevery1Kofprogrammedmemory,i.e.10msecs/1k.However,sincethecommonmethodofmonitoringtheinputsattheendofeachscanisinadequateforreadingcertainextremelyfastinputs,somePLCprovidesoftwareinstructionsthatallowtheinterruptionofthecontinuousprogramscaninordertoreceiveaninputorupdateanoutputimmediately.Also,anewerapproachinPLCdesign,whichresultstoasignificantreductionofthetotalprocessingtime,istodividethetotalsystemloadtoanumberoftasksandassigntheirexecutiontoseveralprocessors.ThestackregisterissodesignedthattheexecutionofaninstructionwhichreadsdiscreteinputsshiftsrightbyonebitthecontentsofthestackregisterandpushesthecurrentstateoftheO.Rflipflopintostackregister.Whenthisoperationiscompleted,theO.Rflipflopisloadedwiththestateofadiscreteinput.Instructionswhichperformlogicoperationsshiftleftthecontentsofthestackregister.Then,theleftmostbitofthestackregisterisloadedintotheO.Rflipflop.Then,thearithmetic,calculationsandnumericalhandlingareusingthedataregistersDROOandDRO1forbyteandwordoperationsrespectively.

可編程控制器應(yīng)用的發(fā)展支持軟件1、序可編程控制器（PLC）構(gòu)成了工業(yè)的控制應(yīng)用中被廣泛地應(yīng)用的即時計算器的一個類別。PLC應(yīng)用的發(fā)展需要PLC總體的配置，包括輸入與輸出類型和位置的數(shù)目以及書寫和應(yīng)用程序的糾錯。通常這些計算機在特定的圖解式的結(jié)構(gòu)化語言中被執(zhí)行[Bekkum93,Hughes89,Jones83]同時程序的糾錯在一個發(fā)展環(huán)境中被實行。大多數(shù)運行環(huán)境[SquareD90,Taylor90]允許程序用超過一種語言中寫，在現(xiàn)行的PLC上通過步進或分段運行，同時檢查輸入和輸出之間假設(shè)的邏輯關(guān)系在每個程序步或短短是否滿意。除此之外，這些環(huán)境提供技術(shù)支持，例如提供輸入\輸出線路圖和程序運行代碼。目前的大規(guī)模生產(chǎn)環(huán)境由一個plc模擬器支持。這允許運行程序在沒有PLC隋況下就可以得到糾錯，也使得大量程序的運行顯得更容易的和降低成本，通過確定程序在操作條件的所有臨界之下操作正確，可以減少PLC基本系統(tǒng)中達不到要求危險條件。然而，最終的發(fā)展目標應(yīng)該是確認作用的特性和程序在所有階段運行準時，在這些階段中那些相互間有聯(lián)系的程序和塊都可能進入。在使用PLC系統(tǒng)過程中，我們可能連續(xù)使用模擬這個方法檢查程序中邏輯的錯誤，同時判斷在一個不完整的程序狀態(tài)下它們的動作。此外，我們可以開發(fā)包含程序發(fā)展環(huán)境的新設(shè)備，使用這種新設(shè)備將會減少一個應(yīng)用程序的程序規(guī)劃和工程努力。它們可能是編設(shè)備，這種設(shè)備支持各種語言以IEC1131-3標準定義的應(yīng)用程序。使用這些語言我們的程序規(guī)劃效率將得到很大的改良，因為它們的每一個都可以用來編制合適的應(yīng)用程序，而且整個的應(yīng)用程序可以與單個可運行的程序相聯(lián)系。其他能減少工程耗費的設(shè)備是指那些能作更容易和更有意義的程序輸入環(huán)境的設(shè)備，這些設(shè)備將會允許我們在一個給定的時間期學習，在不用這些設(shè)備時，我們需學習很多模擬情況。此外，我們可以通過與計算機相連的模擬器組來擴展模擬范圍，設(shè)備之間也可以通過模擬結(jié)果二組成更好的聯(lián)系。這種設(shè)備在本文中，一個節(jié)結(jié)構(gòu)和語言圖形可用來表示一個PLC程序的輸入情況，可能允許我們以我們認為合適的方式設(shè)定顯示和驅(qū)動應(yīng)用程序的模擬結(jié)果。在本文中，一個圖和語言結(jié)構(gòu)可能用來解釋輸入PLC程序，PLC運行要求和模擬結(jié)果的輸出情況。結(jié)構(gòu)的核心是虛擬機器，它是一個模擬用應(yīng)用程序?qū)懭胩囟≒LC的程序運算的軟件模組。虛擬機器可運行的編碼相聯(lián)系，這些編碼來自兩個解釋應(yīng)用程序輸出顯示裝置的配置和輸入條件的定義指令的其他軟件模組。當然，計劃用的設(shè)備并不解決應(yīng)用程序的正時行為的完全證明的問題。然而當他們用商業(yè)效益與所提供的質(zhì)量相比時，以及在不同的設(shè)備和相關(guān)的結(jié)果所出現(xiàn)的情況的測試時間。安培用一個特定的PLC模型依比例選擇設(shè)備的條件下實驗，用來證明所設(shè)觀念可行性。已建立實驗的結(jié)果與從在特定的PLC上的樣本程序的運行所得的數(shù)據(jù)一樣有用。PLC的工作原理可編程控制器是一種特殊的數(shù)轉(zhuǎn)計算機，它是通過來自輸入/輸出位裝置的一個儲存程序和反饋來控制及其或處理運算的。它有兩個主要組成部分：中央處理單元（處理器）和輸入、輸出（I/O）模塊。處理器包含所有智能系統(tǒng)所必須的部件，進一步細分為處理機，存儲器和電源。處理器接受來自各種不同輸入裝置的數(shù)據(jù)，運行來自儲存器的儲存程序，并且輸出正確的指令和輸出裝置。輸入、輸出系統(tǒng)通過與控制器相連接的位裝置形成控制界面。他的目的是處理接受到的各種不同的訊號或把它輸出到位置空間。通過這個處理器系統(tǒng)能夠感應(yīng)和測量機器的物理性能，例如接近，位置，運動，層次，溫度，壓力，電流和電壓。給予檢測到的狀態(tài)或測量到的數(shù)值，處理器通過這一模塊系統(tǒng)，發(fā)出各種不同的裝置，如閥，電動機，泵和警報的控制指令。當系統(tǒng)開始運行時，運行程序開始運行。在程序運行的過程中，處理機讀取所有的輸入，存儲它們數(shù)值到輸入存儲區(qū)域中，同時運行應(yīng)用程序。把運行應(yīng)用程序期間產(chǎn)生的結(jié)果存儲到輸出存儲區(qū)域中。當應(yīng)用程序運行結(jié)束時，處理機使用輸出儲存區(qū)的數(shù)據(jù)更新PLC的所有輸出。讀輸入，運行程序，而親更新輸出的程序的過程被掃描。對作一次掃描所需的時間叫做掃描周期。在極限條件下的掃描周期的數(shù)值通常是由制造業(yè)者提供，通常，他們以每1K程序存儲容量的反應(yīng)時間來敘述掃描時間，例如10ms/1k。然而，因為輸入的通常方法在每個掃描結(jié)束的時候?qū)﹂喿x某些快速的輸入是不充分的一些PLC系