Hello All, What could be issue fapping data flow from a deltav Historian to PI. See screenshot below
Simple thing to check is do you have a good network connection?? If that drops out then you will get the data gaps you are seeing. What do the I tags show during the gaps? is it INF Shut, or shutdown, or something else?? Check your PI interface logs at the time of the data drop off and see if you have any error messages? If you do have error messages, then post them on here (with any IP address/sensitive info blanked out) so people can get a better idea of where the issue is.
Are you using the PI OPC interface to talk to the FRSOPC application on Deltav or are you connecting to the DeltaV Historian direct using the PI-HDA interface?? If your are connecting to the DeltaV historian is the data showing as continuous in DeltaV trends?? If the raw data is intact I would suggest you have a network problem. From my experience the interfaces either work or they don't - they don't drop out ate random intervals.
Sorry that's not a lot of info, but hopefully it gives you somewhere to start.
Thanks for the response. When the data is out, I see Comm Fail. Network connection to the remote system is ok.
I think "comm fail" means that PI cannot see the instrument tag that it is trying to get data from. It sounds like whatever you are connecting to is dropping out intermittently. I have a similar issue with an interface and it is because the remote system sends out Wi-Fi data every 1 hour; the wi-fi connection disables the OPC server functionality temporarily therefore the OPC interface cannot see the OPC server tags and reports comms fail.
How are you connecting to DeltaV? Are you using OPC DA and connecting to the FRSOPC application on DeltaV or are you connecting direct to the DeltaV Historian. What version of DeltaV are you running??
We are using OPC DA.
What OPC server are you connecting to? Is it FRSOPC ??? If you are using OPC DA I don't think that your are talking to the DeltaV historian ( I think that needs OPC HDA).
Where is the PI OPC client installed?? Is it on the same DeltaV apps station as the OPC server you are accessing?? Are you passing data across firewalls??
Comm Failure is almost always indicative of a network or communication error somewhere before the PI layer meaning there is likely some issue with your OPC server communicating to whatever is sending it data. Can you see the comm fail messages when connecting a generic OPC client?
Comm Fail is simply the PI interpretation of an OPC quality code (Communication Failure 000110 LL) See documentation
What is the architecture?
Retrieving data ...