Hi, I'm trying to use OPC (OLE for Process Control) with VS2003 (VB.NET). It worked with VS2002, but the same code in VS2003 throws the following exception: 'System.InvalidCastException' Additional information: QueryInterface for interface OPCSiemensDAAutomation.IOPCGroups failed. The code where this exception occurs is the following: _opcGroups = CType(Marshal.CreateWrapperOfType (_opcServer.OPCGroups, GetType(OPCGroupsClass)), OPCGroupsClass)
Is there anyone who could give me an idea how to solve this problem? Thanks, Joris Zwaenepoel
