Hey Richard, I am sure the vCampus guys will direct you towards OSI TechSupport, sounds like something right up their street to resolve.
I faced a similar problem some months ago. If I remember correctly, I also got error -5 in pipc.log and the problem was being caused by the fact that I was using the SourceTag attribute in the tag configuration instead of InstrumentTag (these tag attribute names can be deceiving for this specific interface...).
So, you may want to make sure you are not making the same mistake as I did.
Rhys is right, we will redirect you to TechSupport... and it is right up their alley.
Anyway, before we officially send you there, just make sure that the "SourceTag" is correctly configured, check in "instrumenttag" "exdesc" and "tag".
We really need to make a differentiation between development support and technical support, and this is a techsupport question. And I such I would to kindly remind you to contact them for an expedite solution at email@example.com.
No one knows what he has until he does an inventory
OK, I've got it sorted out. Server A isn't our main PI server and the people who looked after it did things a little differently. When I went to create the tags on A, I just copied some existing tags. Turns out they were using InstrumentTag instead of ExcDesc like we normally do. When I created the tags on B, the InstrumentTag field was still populated. Clearing that out on server B has fixed it.