OPC客户端编程汇编.doc

OPC编程汇编OPC客户端的自动化实现OPC是建立在COM，DCOM的基础商的，因此绝大多数语言都可以很好的进行开发。在Net中开发客户端有以下几种方式：（1）使用OPCNetAPI，需要用到OPCNetAPI.dll，OPCNetAPI.Com.dll（2）使用自动化接口，需要用到OPCDAAuto.dll（3）使用自定义接口，需要用到多个Wrapper：OpcRcw.Ae.dll，OpcRcw.Batch.dll，OpcRcw.Comn.dll，OpcRcw.Da.dll，OpcRcw.Dx.dll，OpcRcw.Hda.dll，OpcRcw.Sec.dll以上开发方式所需的动态链接库可以从OPC基金会（http:/www.opcfoundation.org/）的网站上下载，一些下载项目可能需要注册，或成为基金会的成员。不同的方式有各自的有缺点，请参见本文使用自动化接口，VB.Net语言进行开发，开发项目是无线射频（RFID）卡方面的应用，典型的如公交车，或公司考勤使用的刷卡机。需要注意的是自动化接口存在一个“不是问题”的问题，数组下标是以1开始的，而不是传统计算机开发上的以0开始。不知道设计者头脑是怎么想（有人知道吗？）；这可能会给一些语言的开发造成问题（有人碰到吗，没有你就是幸运的）需求：OPCDAAuto.dll或该Dll的Interop(一)：客户端开发流程OPC客户端的开发主要遵循下图所示的开发流程，下面就从以下几个开发步骤进行说明(二)：枚举OPC服务器列表枚举服务器主要是通过OPCServer接口的GetOPCServers方法来实现的，该方法会返回OPC服务器数组（以1为下界，上面已有说明），以下是代码段枚举OPC服务器列表PrivateSubForm1_Load(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)HandlesMyBase.LoadTryGlobalOPCServer =NewOPCAutomation.OPCServerClass()DimServerListAsObject= GlobalOPCServer.GetOPCServersForindexAsShort= LBound(ServerList)ToUBound(ServerList)加入控件列表中，注意这里使用LBound和UBoundcbbServerList.Items.Add(ServerList(index)NextIfcbbServerList.Items.Count 0ThencbbServerList.SelectedIndex = 0EndIfResetControlStatus()设置控件状态GlobalOPCServer =NothingCatchExAsExceptionMessageBox.Show(List OPC servers failed: + Ex.Message,OPCSample, MessageBoxButtons.OK)EndTryEndSub(三)：连接OPC服务器自动化接口中连接到服务器是使用connect方法Public Overridable SubConnect(ByValProgIDAsString,Optional ByValNodeAsObject= Nothing)ProgID指服务器的ProgID，Node代表网络节点，如果是本机则放空即可。连接到服务器后，以下属性需要特别注意：OPCServer.StartTime：服务器的启动时间OPCServer.CurrentTime：服务器的当前时间，各个客户端可以通过这个属性值完成一些同步的操作OPCGroups.DefaultGroupIsActive：以后添加的Group是否默认激活OPCGroups.DefaultGroupDeadBand：Group的默认死区，变化量超过死区后将会触发DataChange事件，合理的设置该值可以提高程序性能OPCGroups.Count：下属组（Group）的数量OPCGroups.DefaultGroupLocalID：组（Group）的默认通信区域编号，如1024OPCGroups.DefaultGroupUpdateRate：组（Group）的默认刷新率，该属性也比较重要OPCGroups.DefaultGroupTimeBias：组（Group）的默认时间偏差(四)：添加组（Group）和项（Item）添加组和项需要用到Groups.Add和Items.AddItem方法，以下是原型：FunctionAdd(Optional ByValNameAsObject= Nothing) AsOPCAutomation.OPCGroupFunctionAddItem(ByValItemIDAsString,ByValClientHandleAsInteger) AsOPCAutomation.OPCItem组也有两个重要的属性Group.UpdateRate：刷新率，该属性通Groups的UpdateRate意义一样，如果这个值有设置，则以这个值为准Group.IsSubscribed：是否使用订阅功能以下是代码段连接到指定的OPC服务器PrivateSubbtnConnectServer_Click(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)HandlesbtnConnectServer.ClickIfcbbServerList.Text ThenConnectedOPCServer =NewOPCAutomation.OPCServerClass()TryConnectedOPCServer.Connect(cbbServerList.Text)设置组集合的默认属性ConnectedOPCServer.OPCGroups.DefaultGroupIsActive =TrueConnectedOPCServer.OPCGroups.DefaultGroupDeadband = 0添加组ConnectedGroup = ConnectedOPCServer.OPCGroups.Add()ConnectedGroup.UpdateRate = 3 * 1000刷新虑，用于下面的DataChange事件ConnectedGroup.IsSubscribed =True使用订阅功能添加项GlobalOPCItems(0) = ConnectedGroup.OPCItems.AddItem(Reader_Device.OpenCard, 0)GlobalOPCItems(1) = ConnectedGroup.OPCItems.AddItem(Reader_Device.CloseCard, 1)GlobalOPCItems(2) = ConnectedGroup.OPCItems.AddItem(Reader_Device.CardNO, 2)RefreshServerStatus()刷新服务器状态CatchexAsExceptionConnectedOPCServer =NothingMessageBox.Show(OPC server connect failed : + ex.Message,OPCSample, MessageBoxButtons.OK)EndTryResetControlStatus()EndIfEndSub(五)：读写操作与事件控制读写操作包括同步和异步两种操作方式，以下是这几个方法的原型：Group的同步读事件SubSyncRead(ByValSourceAsShort,ByValNumItemsAsInteger,ByRefServerHandlesAsSystem.Array,ByRefValuesAsSystem.Array,ByRefErrorsAsSystem.Array,Optional ByRefQualitiesAsObject= Nothing,Optional ByRefTimeStampsAsObject= Nothing)Group的同步写事件SubSyncWrite(ByValNumItemsAsInteger,ByRefServerHandlesAsSystem.Array,ByRefValuesAsSystem.Array,ByRefErrorsAsSystem.Array)Group的异步读事件SubAsyncRead(ByValNumItemsAsInteger,ByRefServerHandlesAsSystem.Array,ByRefErrorsAsSystem.Array,ByValTransactionIDAsInteger,ByRefCancelIDAsInteger)Group的异步写事件SubAsyncWrite(ByValNumItemsAsInteger,ByRefServerHandlesAsSystem.Array,ByRefValuesAsSystem.Array,ByRefErrorsAsSystem.Array,ByValTransactionIDAsInteger,ByRefCancelIDAsInteger)如果使用异步的读写操作，那么还需要实现Group中的ReadComplete和WriteComplete两个事件Public EventAsyncReadComplete(ByValTransactionIDAsInteger,ByValNumItemsAsInteger,ByRefClientHandlesAsSystem.Array,ByRefItemValuesAsSystem.Array,ByRefQualitiesAsSystem.Array,ByRefTimeStampsAsSystem.Array,ByRefErrorsAsSystem.Array)Public EventAsyncWriteComplete(ByValTransactionIDAsInteger,ByValNumItemsAsInteger,ByRefClientHandlesAsSystem.Array,ByRefErrorsAsSystem.Array)其他相关的重要事件包括：Group数据变化时的通知事件Public EventDataChange(ByValTransactionIDAsInteger,ByValNumItemsAsInteger,ByRefClientHandlesAsSystem.Array,ByRefItemValuesAsSystem.Array,ByRefQualitiesAsSystem.Array,ByRefTimeStampsAsSystem.Array)Group的异步取消事件Public EventAsyncCancelComplete(ByValCancelIDAsInteger)Server（服务器）关闭通知事件Public EventServerShutDown(ByValReasonAsString)以下是这些实现的代码段读取卡片指定的块号的值PrivateSubbtnReadCard_Click(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)IfNot(ConnectedGroupIsNothing)ThenTry获取块号DimBlockNoAsShort=CByte(ReadBlockNo.Text)如果要获取数据的块所对应的项还没有创建，就创建它IfGlobalOPCBlockItems(BlockNo)IsNothingThenGlobalOPCBlockItems(BlockNo) = ConnectedGroup.OPCItems.AddItem(Reader_Device.Block&CStr(BlockNo), 200 + BlockNo)EndIf准备参数数组DimServerResultsAsSystem.ArrayDimServerErrorsAsSystem.ArrayDimServerHandles(1)AsIntegerServerHandles(1) = GlobalOPCBlockItems(BlockNo).ServerHandle读取值ConnectedGroup.SyncRead(OPCAutomation.OPCDataSource.OPCDevice, 1, ServerHandles, ServerResults, ServerErrors)IfServerErrors(1) 0ThenMsgBox(Read Card Failed:& ServerErrors(1)ElsetxtReadBlockNo.Text = ServerResults(1)EndIfCatchexAsExceptionMessageBox.Show(OPC server Read Card failed: + ex.Message,OPCSample, MessageBoxButtons.OK)EndTryEndIfEndSub写卡片指定块的值PrivateSubbtnWriteCard_Click(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)IfNot(ConnectedGroupIsNothing)ThenTry获取块号DimBlockNoAsShort=CByte(WriteBlockNo.Text)如果要写入数据的块所对应的项还没有创建，就创建它IfGlobalOPCBlockItems(BlockNo)IsNothingThenGlobalOPCBlockItems(BlockNo) = ConnectedGroup.OPCItems.AddItem(Reader_Device.Block&CStr(BlockNo), 200 + BlockNo)EndIf准备参数数组DimServerValues(1)AsObjectDimServerErrorsAsArrayDimServerHandles(1)AsIntegerServerHandles(1) = GlobalOPCBlockItems(BlockNo).ServerHandleServerValues(1) = txtWriteBlockNo.Text写入值ConnectedGroup.SyncWrite(1, ServerHandles, ServerValues, ServerErrors)IfServerErrors(1) 0ThenMsgBox(Write Card Failed:& ServerErrors(1)ElseMsgBox(Write Card Succeed)EndIfCatchexAsExceptionMessageBox.Show(OPC server Write Card failed: + ex.Message,OPCSample, MessageBoxButtons.OK)EndTryEndIfEndSub(六)：断开服务器断开服务器只要使用OPCServer的Disconnect方法几个，以下是代码段：断开到指定OPC服务器的连接PrivateSubbtnDisconnectServer_Click(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)HandlesbtnDisconnectServer.ClickIfNot(ConnectedOPCServerIsNothing)ThenTryConnectedOPCServer.Disconnect()CatchexAsExceptionMessageBox.Show(OPC server disconnect failed: + ex.Message,OPCSample, MessageBoxButtons.OK)FinallyConnectedOPCServer =NothingResetControlStatus()EndTryEndIfEndSub(七)：相关链接非常好的一个OPC技术网站http:/www.opcconnect.com/OPC基金会网址http:/www.opcfoundation.org/国内的一个比较好的OPC网站http:/www.opc-china.com/Index.html(八)：全部源码ImportsSystem.Runtime.InteropServicesPublicClassForm1DimGlobalOPCServerAsOPCAutomation.OPCServerClassDimWithEventsConnectedOPCServerAsOPCAutomation.OPCServerClassDimWithEventsConnectedGroupAsOPCAutomation.OPCGroupClassDimGlobalOPCItems(4)AsOPCAutomation.OPCItemDimGlobalOPCBlockItems(64)AsOPCAutomation.OPCItem枚举OPC服务器列表PrivateSubForm1_Load(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)HandlesMyBase.LoadTryGlobalOPCServer=NewOPCAutomation.OPCServerClass()DimServerListAsObject=GlobalOPCServer.GetOPCServersForindexAsShort=LBound(ServerList)ToUBound(ServerList)加入控件列表中，注意这里使用LBound和UBoundcbbServerList.Items.Add(ServerList(index)NextIfcbbServerList.Items.Count0ThencbbServerList.SelectedIndex=0EndIfResetControlStatus()设置控件状态GlobalOPCServer=NothingCatchExAsExceptionMessageBox.Show(ListOPCserversfailed:+Ex.Message,OPCSample,MessageBoxButtons.OK)EndTryEndSub连接到指定的OPC服务器PrivateSubbtnConnectServer_Click(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)HandlesbtnConnectServer.ClickIfcbbServerList.TextThenConnectedOPCServer=NewOPCAutomation.OPCServerClass()TryConnectedOPCServer.Connect(cbbServerList.Text)设置组集合的默认属性ConnectedOPCServer.OPCGroups.DefaultGroupIsActive=TrueConnectedOPCServer.OPCGroups.DefaultGroupDeadband=0添加组ConnectedGroup=ConnectedOPCServer.OPCGroups.Add()ConnectedGroup.UpdateRate=3*1000刷新虑，用于下面的DataChange事件ConnectedGroup.IsSubscribed=True使用订阅功能添加项GlobalOPCItems(0)=ConnectedGroup.OPCItems.AddItem(Reader_Device.OpenCard,0)GlobalOPCItems(1)=ConnectedGroup.OPCItems.AddItem(Reader_Device.CloseCard,1)GlobalOPCItems(2)=ConnectedGroup.OPCItems.AddItem(Reader_Device.CardNO,2)RefreshServerStatus()刷新服务器状态CatchexAsExceptionConnectedOPCServer=NothingMessageBox.Show(OPCserverconnectfailed:+ex.Message,OPCSample,MessageBoxButtons.OK)EndTryResetControlStatus()EndIfEndSub服务器断开事件通知PrivateSubOnServerShutDown(ByValReasonAsString)HandlesConnectedOPCServer.ServerShutDownbtnDisconnectServer_Click(Nothing,NewEventArgs()EndSubPrivateSubOnGroupDataChange(ByValTransactionIDAsInteger,ByValNumItemsAsInteger,ByRefClientHandlesAsSystem.Array,ByRefItemValuesAsSystem.Array,ByRefQualitiesAsSystem.Array,ByRefTimeStampsAsSystem.Array)HandlesConnectedGroup.DataChangeForiAsInteger=1ToNumItemsIfQualities(i)=OPCAutomation.OPCQuality.OPCQualityGoodThenSelectCaseClientHandles(i)Case2txtCardNo.Text=CStr(ItemValues(i)Case200测试7张卡片txtValueBlock0.Text=CStr(ItemValues(i)Case201txtValueBlock1.Text=CStr(ItemValues(i)Case202txtValueBlock2.Text=CStr(ItemValues(i)Case203txtValueBlock3.Text=CStr(ItemValues(i)Case204txtValueBlock4.Text=CStr(ItemValues(i)Case205txtValueBlock5.Text=CStr(ItemValues(i)Case206txtValueBlock6.Text=CStr(ItemValues(i)Case207txtValueBlock7.Text=CStr(ItemValues(i)CaseElseEndSelectEndIfNextEndSub断开到指定OPC服务器的连接PrivateSubbtnDisconnectServer_Click(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)HandlesbtnDisconnectServer.ClickIfNot(ConnectedOPCServerIsNothing)ThenTryConnectedOPCServer.Disconnect()CatchexAsExceptionMessageBox.Show(OPCserverdisconnectfailed:+ex.Message,OPCSample,MessageBoxButtons.OK)FinallyConnectedOPCServer=NothingResetControlStatus()EndTryEndIfEndSub开卡，并返回卡号PrivateSubbtnOpenCard_Click(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)IfConnectedGroupIsNotNothingThenTry准备参数数组DimServerHandles(1)AsIntegerDimServerValues(1)AsObjectDimServerErrorsAsSystem.ArrayServerHandles(1)=GlobalOPCItems(0).ServerHandleServerValues(1)=1写入值，用于执行OpenCard的操作ConnectedGroup.SyncWrite(1,ServerHandles,ServerValues,ServerErrors)IfServerErrors(1)0ThenMsgBox(OpenCardError:&ServerErrors(1)EndIfServerHandles(1)=GlobalOPCItems(2).ServerHandleDimServerResultAsSystem.Array读取卡号ConnectedGroup.SyncRead(OPCAutomation.OPCDataSource.OPCDevice,1,ServerHandles,ServerResult,ServerErrors)IfServerErrors(1)0ThenMsgBox(ReadCardNoError:&ServerErrors(1)ElsetxtCardNo.Text=ServerResult(1)EndIfCatchexAsExceptionMessageBox.Show(OPCserverOpenCardfailed:+ex.Message,OPCSample,MessageBoxButtons.OK)EndTryResetControlStatus()EndIfEndSub读取卡片指定的块号的值PrivateSubbtnReadCard_Click(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)IfNot(ConnectedGroupIsNothing)ThenTry获取块号DimBlockNoAsShort=CByte(ReadBlockNo.Text)如果要获取数据的块所对应的项还没有创建，就创建它IfGlobalOPCBlockItems(BlockNo)IsNothingThenGlobalOPCBlockItems(BlockNo)=ConnectedGroup.OPCItems.AddItem(Reader_Device.Block&CStr(BlockNo),200+BlockNo)EndIf准备参数数组DimServerResultsAsSystem.ArrayDimServerErrorsAsSystem.ArrayDimServerHandles(1)AsIntegerServerHandles(1)=GlobalOPCBlockItems(BlockNo).ServerHandle读取值ConnectedGroup.SyncRead(OPCAutomation.OPCDataSource.OPCDevice,1,ServerHandles,ServerResults,ServerErrors)IfServerErrors(1)0ThenMsgBox(ReadCardFailed:&ServerErrors(1)ElsetxtReadBlockNo.Text=ServerResults(1)EndIfCatchexAsExceptionMessageBox.Show(OPCserverReadCardfailed:+ex.Message,OPCSample,MessageBoxButtons.OK)EndTryEndIfEndSub写卡片指定块的值PrivateSubbtnWriteCard_Click(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)IfNot(ConnectedGroupIsNothing)ThenTry获取块号DimBlockNoAsShort=CByte(WriteBlockNo.Text)如果要写入数据的块所对应的项还没有创建，就创建它IfGlobalOPCBlockItems(BlockNo)IsNothingThenGlobalOPCBlockItems(BlockNo)=ConnectedGroup.OPCItems.AddItem(Reader_Device.Block&CStr(BlockNo),200+BlockNo)EndIf准备参数数组DimServerValues(1)AsObjectDimServerErrorsAsArrayDimServerHandles(1)AsIntegerServerHandles(1)=GlobalOPCBlockItems(BlockNo).ServerHandleServerValues(1)=txtWriteBlockNo.Text写入值ConnectedGroup.SyncWrite(1,ServerHandles,ServerValues,ServerErrors)IfServerErrors(1)0ThenMsgBox(WriteCardFailed:&ServerErrors(1)ElseMsgBox(WriteCardSucceed)EndIfCatchexAsExceptionMessageBox.Show(OPCserverWriteCardfailed:+ex.Message,OPCSample,MessageBoxButtons.OK)EndTryEndIf EndSub重设控件状态PrivateSubResetControlStatus()IfConnectedOPCServerIsNothingThenbtnConnectServer.Enabled=TruebtnDisconnectServer.Enabled=FalsebtnReadCard.Enabled=FalsebtnWriteCard.Enabled=FalsebtnOpenCard.Enabled=FalsebtnCloseCard.Enabled=FalseReadBlockNo.Value=0WriteBlockNo.Value=0txtReadBlockNo.Text=txtWriteBlockNo.Text=00000000000000000000000000000000txtCardNo.Text=txtSrvStartTime.Text=txtSrvCurrTime.Text=txtSrvGroupCount.Text=txtSrvGroupDeadBand.Text=txtSrvGroupDefActive.Text=txtSrvGroupLocalID.Text=txtSrvGroupTimeBias.Text=txtSrvRequestRate.Text=ElsebtnConnectServer.Enabled=FalsebtnDisconnectServer.Enabled=TrueIftxtCardNo.Text=ThenbtnReadCard.Enabled=FalsebtnWriteCard.Enabled=FalsebtnOpenCard.Enabled=TruebtnCloseCard.Enabled=FalseElsebtnReadCard.Enabled=TruebtnWriteCard.Enabled=TruebtnOpenCard.Enabled=TruebtnCloseCard.Enabled=TrueEndIfEndIfEndSub刷新服务器状态属性信息PrivateSubRefreshServerStatus()IfConnectedOPCServerIsNotNothingThentxtSrvStartTime.Text=ConnectedOPCServer.StartTime.ToString()