.Net OPC Client/Code?

Hi,
A customer has a custom in-house QA system, that we need to link into a PLC or 2.
There is already a SCADA system in place, with IO Servers that can also act as OPC Servers.
What we need, is some example code, or a cost effective package that will allow their developer to read/write to the PLC.

There are plenty out there, just wandering if anyone on the forum can recommend one.

Depending on your type of PLC's this might work. I haven't written the .NET myself, but several of my coworkers have used to to talk to Allen Bradley PLC's and have said it works well. They have versions of it for several different brands of PLC's. At least for the Allen Bradley version there is actually no need for the OPC server, it talks directly to the PLC.

http://www.ingeardrivers.com/index.htm

Try here for info relating programming OPC clients in .NET:
http://www.opcconnect.com/dotnet.php