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PI for OPC-DA Interface update changes how OPCDA server sends data?

Question asked by SHoeser on Apr 16, 2018
Latest reply on Apr 18, 2018 by Steve Boyko

Hello all,

I am writing because we have a "problem"after we updated our PI for OPDDA Interface (OPCInt) from version to The update worked so far, PI is still collecting and archiving data.

After the update however, I have noticed that the compression seemed to be much higher. Here is an example tag (red arrow marks update time):

With markers:


Without markers:


I have checked the compression parameters, but they didn't change.

The I check our second historian, which is pulling data from the same OPC DA server and whose interface software wasn't touched during the update process of OPCInt. Also here, I could see that the "compression" changed, point in time marked by first red arrow (excuse me for pasting a screenshot of a competitors historian, but I need it to make the point):


Then between the second and third Arrow, I stopped the OPCInt service for a few minutes. The data quality went back to the state before the OPCInt update. IMO a sign that the OPC DA server is working fine, but the communication with OPCInt somehow influences how it makes data available. I have browsed the a bit the knowledge base, and explored a bit the new trend advise feature that came with 2.5.0. But after checking our configuration, I would say that we have no Advise Tags configured. Also the /TA parameter is unspecified in the OPCInt1.bat.

At this point I am a bit puzzled and would like to ask the community for help.

Thanks a lot in advance!