I have written lots of data acquisition software on PCs using primitive C and the Win32 API. Many of these applications have interfaced with PLCs through discrete digital I/O. Now I have been asked by the PLC guy if I can replace my use of discrete I/O with an OPC Server over Ethernet (to simplify wiring). What new programming capabilities do I need to acquire in order to do this? I have never used OPC, Ole, .NET, or COM. But I am very familiar with Windows application programming using the primitive Win32 API. I have heard of Kepware, but upon browsing their website, I see nothing that says how my Win32 application can interface with it.