【正文】 NET technology39。 You do have to be a member to access this, however that offers other advantages such as invitations to the OPC Interoperabilty events to test your client against other vendors.If that39。re new to OPC, this is not a trivial task...s site.re best option is to get the OPC Foundation39。opc refs below)1) 2) I only dimly understand the article on d be laughing.is interesting and gives me hope, I39。 If OPC is a standard, can I not just use any OPC interface and hope that RSLinx (the Rockwell OPC server) answers with the right data?Answer 7I was looking for some help developing a C OPCOPC clients using the wrapper.opc Since doesn39。 Each vendor then repiled the code under their own GUID In November of 2005, the OPC Foundation decided to take the responsibility of maintaining various applications All the bug fixes various vendors had applied over the years was piled and the OPC Foundation released the 39。 (I assume it39。39。Answer 11Post your code here to have a look at it, leandroAre you using a reference to COM OPC?Altough the exception is very clear.Answer 14Sorry , this one should workHere a sample of the code:39。Answer 13The link you posted doesn39。39。their39。 . When the first OPC DA specifications were released, the OPC Foundation did not wish to support plied applications, so the source code for the was supplied to all OPC members.s called the Automation Wrapper, or .opc Option Base 139。Answer 9Andrew, Perrakus is correct in his discription on using the Automation dll with .opc clientusing the OPCAutomation wrapper when I stumbled upon your conversation. Here is a link to a sample OPC client that helped shed some light on using .Net toAnswer 6You can use or c with rslinx39。m still trying to figure out how I can use the OPC interface designed for VB6 with .m not. The problem is the that Rockwell use to interface to their OPC server (RSlinx).Answer 5Hi Eric, Sounds like you know what you39。s excellent .NET interface library here:Again, do not assume that this is of any mercial quality amp。opc From an programatic point of view, an OPC client would be no different from any other COM client. This was originally intended for VB apps, but some vendors have upgraded the automation interface to work with client re fishing for a response, flattery will get you everywhere :)As the other replies pointed out, the question is a bit open ended.s a wee bit over the top, let39。 I39。?I know that Eric Murphy is an OPC genius, and he can probablyAnswer 2Hey Ksona,I was just speaking to a college of mine about DA cleints this morning.but am still not sure how to implement it, can someone give me a direction on how to start with it?Async WriteDim ItemVal(ItemCount) As VariantFor i = 1 To ItemCount ItemVal(i) = iNext i 16, ItemServerHandles, ItemVal, ItemServerErrors, 100, 101Private Sub Mygroup_AsyncWriteComplete(ByVal TransactionID As Long, _ ByVal NumItems As Long, ClientHandles() As Long, Errors() As Long) AsyncWrite Comp + Chr$(9) + Time$ + Chr$(13) + Chr$(10)End SubCache ReadIn cache read operation, OPC Server doesn39。39。Dim ClientHandles(16) As LongDim OPCItemIDs(16) As StringSet Mygroups = Set Mygroup = (Group1) = 1000 = FalseFor i = 1 To 16 ClientHandles(i) = i OPCItemIDs(i) = Device1 + .D + Format(i)Next iSet Myitems = 16, OPCItemIDs, ClientHandles, ItemServerHandles, ItemServerErrors = TrueAdvise and CallbackImplements event handler of OPC Group object for advice mode. The OPC Server read data for each cycle and if changing the value, callback to client application. The quality flag is normally 39。Dim Getserver As OPCServerDim Servers As VariantSet Getserver = New OPCServerServers = For i = LBound(Servers) To UBound(Servers) Servers(i)Next iSet Getserver=Nothing Connect and BrowseIt is able to get device name registered in OPC Server by using OPC Server object. You can make the Group under device and OPC Server object is enabled to access this lower layer.D039。 EndEndNothingAsIs)Handles,SubEndTryConnectedOPCServer =Exception39。True39。()Try() esender 39。Sub(List OPC servers failed: ExceptionGlobalOPCServer =IfToindexServerList)Handles,SubConnectedGroupConnectedOPCServerGlobalOPCServerClassPrerequisites: ComboBox control named cbbServerList, Button1 and Button2 on Form1.Code BlockPublicEnd)serverCatchIfServerHandles,=DimObjectAsIsNotesender39。Sub==ElseTrueIfCStr(.DefaultGroupDeadband)=ConnectedOPCServer39。Sub===============C