Emerson Exchange 365

Item not updating automatically

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This particular user has an alarm that goes off at 8:15 every day, an OPC Quick Client will pick up item change; At random times, this item event will not occur, and when it does not, we get the attached error. 

I did some research but only got so far, I think it might be a memory leak, but I don’t know where to look. or what questions to ask. Any help would be greatly appreciated. 

Rene Garza

• 27 Feb 2018 8:08 PM
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1 Reply

• Andre Dicaire

  

  • 27 Feb 2018 11:17 PM

  If you don't receive an input from someone that has seen and solved this exact symptom, I would strongly recommend a call to the GSC for formal investigation.
  
  As for the error message, the initial part I've seen due to how I'm looking at the event log (from another computer). The crux of this message is:
  
  Unsol Callback received but package is out of sequence. Process ID=11904.
  
  The process ID would point to the program running on your computer so that would be unique to your machine. If you checked Task Manager Processes and could correlate the program at that Process ID, that might be useful information to have.
  
  The package out of sequence is interesting. A long time ago, I found that a bad port on a switch handling OPC data was causing dropped packets. OPC DA used TCP transport protocol and dropped packets were being retransmitted by TCP. Since some packets got through, the retransmitted packets ended up being out of sequence and the destination OPC server was showing the wrong state for some values.
  
  Your description indicates the OPC Quick Client is an OPC DA client. Is this client installed on theDeltaV Appstation? If so, your issue is not what I encourntered. If the client is on a non-deltaV computer, maybe it is related. I did not check the windows logs at the time so I can't confirm if my issue had the same log events. But I had a bad port on the switch connecting the two computers, which we saw through switch diagnostics (a third party switch on the integration network).
  
  The term "unsol" makes me wonder if this is related to DeltaV Unsolicited communications, but these use UDP traffic and I don't think we would see an Out of Sequence message from DeltaV. Something the GSC would be able to assist with.

  Andre Dicaire

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