VB+OPC代码.doc

OPC的VB例子 Option ExplicitOption Base 1Private QOpcServer As OPCServerPrivate QGroups As OPCGroupsPrivate WithEvents QGroup As OPCGroupPrivate QItems As OPCItemsPrivate QItemServerHandles() As Long Private Sub Form_Load()On Error GoTo ErrorHandler????建立与OPC服务器的连接????Set QOpcServer = New OPCServer????Call QOpcServer.Connect(S7200.OPCServer) S7200.OPCServer是固定的OPC名称????????建立一个数据群组????Set QGroups = QOpcServer.OPCGroups???????? Get OPCGroups Collection Object from QOPCServer???? Set Default Properties for Group Collection???? These Properties are used to set the Properies for new Groups????QGroups.DefaultGroupIsActive = 500?? Set Default Group Update Rate to 500 ms????QGroups.DefaultGroupIsActive = False Set Default Group Active State to Inactive????Set QGroup = QGroups.Add(QGroup1)?? Add a new Group to the Group Collection???? Set Group Properties????QGroup.IsSubscribed = True?? Enable Callbacks????QGroup.UpdateRate = 100???? 这个群组的刷新速度是100ms????????往群组里添加要传送的地址单元????Dim i As Long????Dim ErrorFlag As Boolean????Dim ItemObj As OPCItem????Dim ItemIDs(2) As String????Dim ItemClientHandles(2) As Long????Dim Errors() As Long???????????? Array for returned Item related errors????ErrorFlag = False????Set QItems = QGroup.OPCItems?????????? Get OPCItems Collection Object from QOPCServer???? Initialize the [IN] parameters for the Add Items call???? ItemIDs - ItemIDs of the Items to add???? ItemClientHandles - Client defined handles for the Items. The Server sends these handles in the Callbacks????ItemIDs(1) = 2,q1.0,bool?? Read ItemId 1 from Text Box????ItemIDs(2) = 2,VW10,Word?? Read ItemId 2 from Text Box????ItemClientHandles(1) = 1????ItemClientHandles(2) = 2???? [OUT] parameters are???? ItemServerHandles - Server defined handles for the Items. The client must use these handles for all Read/Write calls???? Errors - Item related errors???? Add Items to the Group????Call QItems.AddItems(2, ItemIDs, ItemClientHandles, QItemServer