《OPC接口技术》PPT课件

OPC接口技术,谈英姿tanyz东南大学自控系工业自动化教研室,内容提要,概述OPC基本原理OPCDA接口标准OPCAE接口标准OPCHDA接口标准OPCXML接口标准,OPC基本原理,通用OPC结构及组成对象及接口概述必需的接口定义可选的接口定义服务器地址空间及配置时间同步与顺序发送机制EnumOPC对象属性条目,通用OPC结构及组成,OPC数据访问规范OPC报警和事件规范OPC数据交换规范OPC历史数据访问规范OPC批处理规范OPC安全性规范OPCXML规范,对象及接口概述,OPC对象OPC对象有三个：服务器(OPCServer)、组(OPCGroup)和项(OPCItem)OPC接口,服务器,OPCServer即OPC启动服务器，通过它获得其他对象和服务的起始类，并用于返回OPCGroup类对象。OPCServer级别有多种属性，其中包含一个OPC服务器对象的状态和版本等信息。这种级别中的对象由客户应用创建。IOPCServer接口包含管理OPCGroup级别中的对象的方法。如将组加入服务器或从服务器中删除组的方法（AddGroup，RemoveGroup）。IOPCBrowseServerAddressSpace接口包含查找服务器地址空间的方法。IOPCCommon接口方法用于通知服务器语言的设置和客户机的名称。,标准OPC服务器对象,必需的接口定义,OPC服务器必需的接口有IunknownIOPCServerIOPCCommerIConnectionPointContainer,组(OPCGroup),OPCGroup存储由若干OPCItem组成的Group信息，并用于返回OPCItem类对象。OPCGroup级别管理被称为OPCItem的各个过程变量。IOPCItemMgt接口提供将项加入组或从组中删除项的方法（“AddItem”，“RemoveItem”）。IOPCGroupStateMgt接口的方法用于处理组专用的参数或复制组。,标准OPC组对象,项(OPCItem),OPCItem存储具体Item的定义、数据值、状态值等信息。OPCItem级别的一个对象代表与一个过程变量的连接。该对象的唯一接口是OPCItemDisp。关于OPCItem的信息可以在属性表中找到，例如数值（“Value”）属性或存取路径（“AccessPath”）属性。,OPC项对象,OPC的过程数据构造,OPC项代表了与服务器中的数据的连接。客户程序对OPC项的操作都是通过包容此项的OPC组来进行的，而不是直接把OPC项作为一个对象来操作。每个OPC项都有值(Value)。品质(Quality)和时间戳(TimeStamp)三个属性。,EnumOPC对象属性条目,OPC客户与OPC服务器,自定义接口与自动化接口,OPCAutomationwrapper,Automationclient(VisualBasic,Excel,),custominterface,server,Customclient(C+,.),custominterface,server,自定义接口与自动化接口,自定义接口效率高，通过该接口，客户能够发挥OPC服务器的最佳性能，采用C语言的客户一般采用定制接口方案；自动化接口使解释性语言和宏语言访问OPC服务器成为可能，采用VB等语言的客户一般采用自动化接口,OPCDA接口标准,数据访问方式DA功能实现过程DA的对象与接口,数据访问方式,DA的同步读取DA的异步读取DA的数据更新DA的数据订阅DA的同步写入DA的异步写入,DA的同步读取,DA的异步读取,DA的数据订阅,数据订阅传输模式,数据源:cache/device,clientapplication(OPCclient),fieldbus,OPCserver,cache,fieldbus,device,fieldbus,device,fieldbusconnection,serversamplesitems(attheRequestedUpdateRate)andputsthemintocache,synchronouscalloverthefieldbustotheenddevice(takesawhile),noneedfor“deviceaccess”whenfieldbusoperatescyclically,FBmanager,FBagent,FBagent,SynchReadreadsthedataeitherfromcache(localtothePC)orreadssynchronousfromthedevice.Writeisalwaystodevice(DA3.0allowswritetocache),DA功能实现过程,OPCDA客户连接到DA服务器，建立OPCGroup和OPCItem；通过Group和Item进行数据访问；处理完毕，关闭连接。,OPCDA对象的层次模型,OPCItem,OPCBrowser,OPCServer,OPCGroups(collection),OPCGroup,OPCItems(collection),OPCItem,OPCItem,OPCGroup,OPCDA初始化连接,findoutexistingOPCservers,connecttothatOPCserver,createanOPCBrowserobjectcreateanOPCGroupsobject,createanOPCServerobject,createanOPCGroupobject,buildarrayofitemscheckingwiththebrowserthattheseitemsexistinthisserver,additemarraytothegroup,activateandsubscribegroup,nextgroup,初始化,myDummyServer.GetOPCServers,myServer.Connect,SetmyBrowser=myServer.BrowserSetmyGroups=myServer.Groups,myServer=newOPCServer,SetmyGroup1=myGroups.AddSetMyItems=MyGroup1.OPCItems,FQItems11=Device1.Temp1ClientHandle11=101ReDimServerHandle1(nrItems)ReDimServerErrors1(nrItems)ReDimValue1(nrItems),myGroup1.AddItems,myGroup1.IsActivemyGroup1.IsSubscribed,Declarations,OptionBase1OPCarraysindicesstartwith1DimWithEventsMyServerAsOPCServerOPCServerObject(Eventsoptional)DimWithEventsMyGroupsAsOPCGroupsOPCGroupCollection(Eventsopt.)DimWithEventsMyGroupAsOPCGroupOPCGroupObjectitemsDimnrItemsAsIntegerDimMyItemsAsOPCItemsOPCItemCollectionObjectDimMyItemAsOPCItemOPCItemObjectDimItemsID(2)AsStringfullyqualifieditems(seelater)DimClientHandles(2)AsLongDimServerHandles()AsLongmustbeadynamicarrayDimServerErrors()AsLongmustbeadynamicarray,Reference:OPCAutomation2.0mustbeincludedintoVisualBasicorC#(ifmissing:copyopcdaauto.dlltoC:WINNTSystem32opddaauto)andregisterit:C:regsvr32C:WINNTSystem32opddaauto.Asimplewaytodoit:installSoftwareToolboxsTopServer(freeware),查找OPC服务器,TheGetOPCServersfunctionappliedtoadummyServerobjectallowtolisttheexistingserversonthisnodeoronanothernode(overDCOM-securitymustbesetcorrectly)TheinformationaboutwhichOPCserversexististakenfromtheregistry,whereithasbeenputbyeachserveratitsinstallationtime。,PrivateSubShowServers(netNodeNameAsString)DimdummyServerAsOPCServerDimServersAsVariantthisisanarrayofstringsDimcntServersAsIntegerSetdummyServer=NewOPCServercreateadummyserverobjectServers=dummyServer.GetOPCServers(netNodeName)returnsallavailableserversForcntServers=LBound(Servers)ToUBound(Servers)displaythenamesMsgBoxServers(cntServers)NextcntServersSetGetserver=Nothingdeletethisobject(wascreatedbyNew)ExitSub,连接到OPC服务器,SetMyServer=NewOPCServercreateserverobjectMyServer.Connect(Matrikon.OPC.Simulation)connecttoMatrikonserver,Beforeconnecting,itissafetocheckthenameoftheserverfromtheserverslist.Also,itispreferabletoincludetheconnectioninaseparateroutinesinceitcanfail:,FunctionServerGetCare(NameAsString,ServerNodeAsString)AsOPCServerOnErrorGoToServerGetCareErrDimMyOPCServerAsNewOPCServerMyOPCServer.ConnectServerName,ServerNodeconnectriskySetServerGetCare=MyOPCServerExitFunctionServerGetCare_Err:errorhandlerifconnectfailsErr.ClearMsgBoxCouldnotconnectSetMyServer=NothingExitFunction,浏览服务器,TheobjectOPCBrowser(oftypecollection)actsasapointertotheserverstree:,DimMyServerAsOPCServerDimMyBrowserAsOPCBrowserDimvNameAsVariantMyServer.ConnectMatrikon.OPC.Simulation,Orionserverandnodename(DCOM)SetMyBrowser=MyServer.CreateBrowsercreateanOPCbrowserMyBrowser.ShowBranchesshowthebranchesForEachvNameInMyBrowserMsgBoxBranch:Tanks!Level,创建OPCGroupsandOPCItems,SetMyGroups=MyServer.OPCGroupscreategroupscollectionSetMyGroup1=MyGroups.Add(GRP1)addgroup,nameprivateSetMyItems=MyGroup1.OPCItemsdefinetheOPCItemsofgroupFQItemIDs(1)=Area2.Tank1.LevelfullyqualifieditemIDClientHandles(1)=5arbitraryFQItemIDs(2)=Area2.Tank1.TemperaturefullyqualifieditemIDClientHandles(2)=6arbitrary(butdifferent)nrItems=2MyItems.AddItems_addstheitemstocollectionnrItems,_inputparameterFQItemIDs,_supplyfullyqualifiedIDClientHandles,_supplyClientHandlesServerHandles,_returnparameterServerHandlesServerErrorsreturnparameterServerErrorsMyGroup1.ClientHandle=1handleofthegroup(nos)!MyGroup1.IsActive=TruenowreadytosendandreceiveMyGroup1.IsSubscribed=Trueandtogenerateevents,TheroleoftheServerHandlesandClientHandleswillbeexplainedlater,客户端的数据结构,FullyQualifiedItemID,ClientHandle,ServerHandle,Channel1.Device1.Temp1,communicatedtoserverbyregisteringgroup,ServerError,Value,Quality,TimeStamp,100,34543,0,123.4,OK,12:09.234,Channel1.Device1.Speed1,102,22532,0,999.8,OK,12:02.214,Channel1.PLC2.Door,203,534676,0,0,OK,12:03.002,Channel1.PLC2.Valve3,204,787234,0,1,OK,12:02.345,Channel1.PLC2.CloseDoor,205,58432,0,0,BAD,12:02.345,returnedbyserverwhenregistering,dynamicchanges(refreshedonchange),Theclientpreparesdatastructuresforitsitemsandgivestheserverthecorrespondingpointerssotheservercanupdatethem.Itemstobewrittenandreadcanbemixedinthesamegroup.Thetypeoftheitem(Boolean,Float,)isimplicit,butknownattheserver,.,.,.,.,.,.,DimthisGroupAsOPCGroupDimcntItemsAsIntegerDimsourceAsIntegerDimserverHandles(2)AsLongDimvalues()AsVariantDimerrors()AsLongserverHandles(1)=ServerHandle(11)copyfromglobalvariablesserverHandles(2)=ServerHandle(14)source=OPCcachecouldalsobeOPCDevicethisGroup.SyncReadsource,nrItems,serverHandles,identifiestheitemstoberead!values,returnsbeadynamicarrayerrorsreturnsadynamicarrayForcntItems=LBound(serverHandles)ToUBound(serverHandles)1.nMsgBoxCStr(cntItems)&:&values(cntItems)NextcntItems,myGroup.SynchRead(),client,Call,Reply,server,Group的同步读,singleItems的异步读,AsyncRead(),AsyncReadComplete(),server,DimWithEventsMyGroup.MyGroup.AsyncReadnrItems,ServerHandles,ServerErrors,TransactionID,CancelID,Call,Reply,client,PrivateSubMygroup_AsyncReadComplete(ByValTransactionIDAsLong,ByValNumItemsAsLong,ClientHandles()AsLong,ItemValues()AsVariant,Qualities()AsLong,TimeStamps()AsDate,Errors()AsLong)MsgBox(AsyncReadComplete)EndSub,AsynchronousreadseparatesCallandReply.CallsuppliestheServerHandlesReplyreturnsthecorrespondingClientHandles,AsyncRead(source=device),AsyncReadComplete(),server,Call,Reply,client,AsyncRead(source=cache),AsyncRead(source=device),AlthoughtheAsynchReadCompletecarriestheClientHandleofeachitem,itdoesnottellwhichAsynchReadcausedtheAsynchReadCompleteeventtofire.,CallandReplyarelinkedbytheTransactionID:thisIDisreturnedinAsynchReadComplete。Itcanalsobeusedtocanceltheoperation,AsyncCancel(),AsyncCancelComplete(),TransactionID,Reading(byevents)theOPCgroup,DimWithEventsMyGroup.PrivateSubMyGroup_DataChange(_ByValTransactionIDAsLong,_ByValNrItemsAsLong,_ClientHandles()AsLong,_returnedbytheservertotheclientItemValues()AsVariant,_Qualities()AsLong,_TimeStamps()AsDate)DimcntItemsAsIntegerForcntItems=LBound(ClientHandles)ToUBound(ClientHandles)index1.nTextValue(cntItems-1).Text=ItemValues(cntItems)displayTextTimeStamp(cntItems-1).Text=DateAdd(h,9,TimeStamps(cntItems)TextQuality(cntItems-1).Text=Qualities(cntItems)NextcntItemsEndSub,ThisfunctioniscalledeachtimeaniteminthegroupchangesTheClientHandles(here:5and6)identifiesthevariables,notthe“fullyqualifieditemID”ThevaluesaredisplayedintheTextValue,TextTimeStampandTextQualityfields.Therefreshrateisgiveninthegroupdefinition.,GroupsEvents,AlthoughtransmissionbygroupsismoreefficientthanAsyncRead,itcanbeimprovedbyusingGroupsEvents(GlobalDataChange)Thiseventisfiredwheneveravariableofagroupchanges.IfthegroupissubscribedalsotoaGroupEvent(DataChange),I.e.ifthegroupisdeclaredWithEvents,thenbothEventswillbefired.Theapplicationmustsortoutthegroupsandtheitems.,GlobalDataChange,DimWithEventsMyGroupsAsOPCGroups.PrivateSubMyGroups_GlobalDataChange(ByValTransactionIDAsLong,=0ifcalledbyRefreshByValGroupHandleAsLong,ByValNumItemsAsLong,ClientHandles()AsLong,identifiestheitemsItemValues()AsVariant,valueoftheitemsQualities()AsLong,valueoftheitemsTimeStamps()AsDate)timestampsoftheitemsSelectCaseGroupHandledependingonthegroup.Case1treatgroup1Case2treatgroup2,TheGlobalDataChangeeventisfiredwhenanyiteminagroupchanged.(ifGroupsisalsowithevents,thecorrespondingGroup_DataChangewillalsobecalled),OPCDA:ServerEvents,DimWithEventsMyServerAsOPCServerdefinetheevent.PrivateSubMyserver_ServerShutDown(ByValReasonAsString)MsgBoxmyOPCServer&MyServer.ServerName&quitEndSub,Thiseventsignalstotheclientthattheservershutdown.TheclientmustdeclareitsserverWithEvents“andprovidethecorrespondingeventSubroutineThisshouldstopallactions,otherwiseexceptionswilloccur.,OPC的断开,PrivateSubServerShutdownDimdummyServerAsOPCServerDimServersAsVariantthisisanarrayofstringsDimcntServersAsIntegerSetmyGroup1=NothingcreateadummyserverobjectSetmyGroups=NothingreturnsallavailableserversMyServer.RemoveMyServer.RemoveAllGroupsMyServer.Disconnectdeletethisobject(wascreatedbyNew)SetMyServer=Nothing,Tospeedupconnection/disconnection,anOPCserverremembersitsgroupsandclientswhenaclientdisconnects.Todothis,anOPCserverinitialisesitsstructureswithaclientcounterof2,insteadof1.Therefore,itisimperativetoshutdownexplicitlytheserver,otherwiselinkswillsubside(andyouwillhavekilltheservertoclearthem).,OPCDA的类库,TheOPCDAspecificationisnotformal,conformancecanhardlybecheckedagainstthisdocument.Toensurethatthestandardisobserved,theOPCfoundationdistributesonitswebsitetheDLLs(opcdaauto.dll,opccomn_ps,)thatcontainthetypelibrariestoaccesstheOPCserver.Thevendorsarenotcompelledtoimplementallfeatures.Forinstance,thedescriptionofthevariablesisseldomused.CallingunimplementedfunctionscausesexceptionsthatmustbecaughtinVisualBasicwithOnErrorstatements.ThereexistthreeversionsofDA,1.0,2.0and3.0,thatbehavedifferently,however,olderserversdonothaveapropertyindicatingwhichversiontheysupport.,OPCAE接口标准,AE相关概念AE的组态AE的目的AE通信模式事件的种类报警的条件报警确认,AE相关概念,AneventisageneralchangeofstatethatisrelevanttotheOPCserver.Aneventsignalachange:1)inthefielddevice(productionstarted)2)intheOPCserver(alarmacknowledged)3)intheapplication(operatoraction)AnalarmisastateoftheprocessthatrequiresattentionandisrelevanttotheOPCserver.Analarmisrepresentedbyanalarmcondition,(orshort:condition),astatemachineindicatingifthealarmhasbeenenabled,triggeredoracknowledged.,AE相关概念,Aneventoranalarmdoesnottransmitanalogueprocessvalues,buttheytransmitinformationabouttheirorigin,thetimeoftheiroccurrenceandamessageintendedforahumanoperator.Alarmsandeventsmaynotgetlost(contrarilytoOPCDA,whichdoesnotguaranteecompleteness)Alarmsandeventarepreciselytime-stampedbytheirsource,(contrarilytoprocessvariables,whicharetime-stampedbythereceivingOPCserver).,controller,OPCAECliente.g.eventlogger,OPCAEServer,e.g.Ethernet,controllers,fielddevices,OPCAECliente.g.alarmprinter,OPCA&Especifiedinterface,plantmeasurementpoints,eventnotification,AnOPCAEServerisconfiguredusingtheinformationcomingfromthedevelopmenttoolsforthecontrollers,events,EventsdefinedinthecontrollersaremirroredtotheOPCAEserver,controller,fieldbus,AE的组态,AE的目的,Thecontrollers(PLC)generateeventsinresponsetochangesintheplantvariablestogetherwiththeirprecisetimeofoccurrence,type,severityandassociatedmessageforthehumanoperator.AnOPCEventserverregisterstheseeventsandmakesthemavailabletoseveralclients.Aparticularclassofeventsarethealarms,whicharedetailedeventsthatmayrequireacknowledgement.,AE的功能,TheOPCAlarms&EventsInterfacegivesaccesstotheOPCEventserver,allowingto:-browsetheOPCA&EServerforpredefinedevents.-enableordisablealarmsandevents-subscribetoalarmsandeventsofinterest-receivetheeventandalarmnotificationswiththeassociatedattributes-acknowledgealarms,AE通信模式,OPCAEworksaccordingtothe“messagepassing”paradigm,contrarilytoOPCDA,thatworksaccordingtothesharedmemoryparadigm.Thismeansthataneventiskeptinaqueueuntilallclientshavereadit(ortimedout).Theserverguaranteesthatdifferentclientswillseealleventsinthesamesequence.,OPCAEClient,OPCAEClient,OPCAEServer,12:3423.114,12:3432.334,报警与事件的显示,Alarmsandeventsareusuallydisplayeddifferentlyonanoperatorscreen.-Eventsaredisplayedinaneventlistthatcanbecomequitelong(typically1000entries),entriesarenotclearedwhenthesourceoftheeventreturnstonormal-Alarmsaredisplayedinashortlist(typically50alarms)appearancechangeswhenthealarmisacknowledged,analarmlineisclearedwhenthealarmsignaliscleared.,Ackcheckbox,Server的组成,Areas,Events,Conditions(alarmsonly),Subconditions(alarmsonly),A2,A23,E1,C2,SC3,SC1,SC1,E2,simple,conditionrelated,A24,C2,SC3,SC1,SC1,E2,conditionrelated,S2,Sources(objects),E1,S1,E2,S3,Aneventisidentifiedbyasource(ownerobjectinthecontroller)andaneventnamethiscombinationmustbeuniqueintheAEServer.,C2,SC1,E3,conditionrelated,tracking,branches,properties,leaves,BrowsingtheAEServer,Area1,Area52,Area2,Area5,Area51,Source1,Source2,Source3,AlarmsandEventareorganizedbyarea,whichthemselvesmaycontainotherareas.ContrarilytobranchesinOPCDA,areaandsourceshavepropertiesthatallowtodisableorenableeventsoralarmsbyareaorbysource,correspondingtopartsoftheplants,roomsorspecificequipmentoftheplant.,root,Browsingmethods,LikeallotherOPCServers,anOPCA&Epresentsaninterfacethatallowstheclienttobrowsetheservertoexploreitsstructure,withthemethods:BrowseOPCAreaChangeBrowsePosition(up,down,root)GetQualifiedAreaNameGetQualifiedSourceNameThereisnoGetQualifiedItemID,sincetheconditionnameisknownfromthesource.,事件的种类,OPCAEdefinesthreekindsofevents:simple:processcontrolsystemrelatedevents(changeofabooleanvariable)condition-related:notifiesachangeofanalarmcondition(CLEARED,ACKNOWLEDGED),(seelater)tracking-related:originoutsideoftheprocess(e.g.operatorintervention),Event-identification,Tank1,Tank2,Tank3,event,HiLevelCond,HiLevelCond,Aneventisidentifiedby-itssource(theobjectthatgeneratestheevent.e.g.Tank1)and-theeventname(whichcanbethesameasinanotherobject,e.g.HiLevelCond),event,HiLevelCond,event,event,LoLevelCond,LoLevelCond,event,LOLevelCond,event,EventPLCFunctionblock,eventsignal(booleanexpression)isanexternalsignaltobeused?signalnameforexternalsignal(20characters)nameofthesource(30characters)message(60characters),SimpleEventfunctionblocksinacontrollerareusedtosignalasimpleevent.Theeventisidentifiedbytheconcatenationofthenameofthecontainingobject(SrcName)andtheeventhandlingfunctionblockname(here:SimpleEventDetector_1).Thesourcenamecanbethatofthecontainingcodemodule(ownerobject),assumingthataplantobjectisrepresentedbyacodemodule.,nameoftheevent,Events-Notification,LevelSwitch,OPCAEServer,timestamp,AEClient,eventnotification,Tank1LevelHigh_SimpleEvent(source,timestamp,message,severity,category),EventFB,Controller,Plant,Tank1,message,queue,Events-TimeStamp,Therearethreeplaceswhereeventscanbetime-stamped:-atthedevicethatoriginallyproducedthedata(externalevent-low-levelevent)allowingSequence-Of-Eventswithahighresolution,downtomicroseconds-atthecontroller,(internalevent)usingthecontrollersclocktotime-stampmessagesgivingprecisionnotgreaterthantheperiodofthetasks,about1ms.-attheOPCServer,whenaneventmessagearrives(trackingevents)notmoreprecisethanDA,about10ms),TheOPCservercanbeconfiguredtoregisterthetimestampattheinstantoftheeventtransition(positiveornegative)andtheinstantoftheacknowledgement.,PropertiesofanEvent-object,PropertyMeaningSourcesourceobject(area+source)TimetimeofoccurrenceMessageassociatedmessagefortheoperatorEventCategoryuser-definedSeveritypriority(1.1000)OPCEventAttributeConditionNamenameoftheconditionwithinthesourceSubConditionnameoftheactivesubcondition(subconditionsareexclusive)ChangeActiveStateChangeAckStateChangeEnableStateChangeQualityChangeSeverityChangeSubConditionChangeMessageChangeAttributeConditionActionConditionAcknowleddgedQualityAckRequiredActiveTimeCookieserverhandleusedforacknowledgementofalarmsActorIDidentifiedwhoacknowledgedthealarm(forclient-sideacknowledgement),allevents,condition-relatedevents,报警的条件,An(alarm)conditionisanamedstatemachinethatdescribesthestateofanalarmTheconditionstateisdefinedbythreevariables:Enabled:theconditionisallowedtosendeventnotificationsActive:thealarmsignalistrueAcknowledged:thealarmhasbeenacknowledged,Alarmsignal(e.g.FIC101.PV100ANDFIC101.PV150),Acknowledgementsignal(apositivetransitionofabooleanvariable),Conditionstate,Enable(posit