@ paulengr : Yes , this definitely is a rant . I'm not MS fan boy (more like Python fan boy), but if your target platform is Windows I find VS and OPC very easy to use. So far Interop ( .NET <=> COM ) worked for me every time - have quite a few projects installed and running for years. I don't know anything about Omron though - my place uses AB-Rockwell almost exclusively and I don't use VB.NET but C#. And I definitely would not like go back to VB6. @valerio : If you are still interested send me a message.
