Random lose of series MQ controller Redundancy

Dear All

I've deltav system  with 2 redundant  DCS series M  controller and other two pairs for ESD , 6 ows, 2 ews, one Pro plus  version  14.31 lts

On diagnostic DCS ctrl  Keeps giving yellow alarm that redundant fail /not available as shown below.

Then everything goes well for 3 to 5 min then gives the same error again also for 3 to 5  min .

I've removed one ctrl the system runs  smoothly by the other .( do not matter you remove active or standby)

Then returned it back , after synchronizing the error is  repeated again.

This issue is in DCS ctrl only

note some I/o channels are open and other give error but should not disturb REDUANDANT CTRL PAIR

Also in some place it shows IO error in the standby controller 

please advise

Thanks

hagouda

• 10 Aug 2025 2:58 PM
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4 Replies

• jgrunschel

  

  • 15 Aug 2025 3:59 PM

  This happens without any interaction with the system?
  
  When you perform a download (and I think also an upload) the redundancy "goes away" while the controllers are doing the download/upload. I don't know the under-workings of the controllers, but I believe this is part of how the controllers function.

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• Andre Dicaire

  

  • 15 Aug 2025 5:16 PM

  This is something you should report to GSC. They would be able to work with you to identify the underlying cause. They would confirm things like the installed Firmware on both processors, hardware resources, etc.
  
  The only thing that comes to mind for me is if the redundancy link on the carriers is not firmly connected, causing the standby to request a new download. The redundancy connection on the M series is at the top of the carriers. If this is not firmly connected, it might be inducing this behavior, where the standby gets its download via the DeltaV network from the Pro Plus, but is unable to synchronize and receive updates from the active. And as a result, resets and starts over. I'm speculating and it might not be this. So again, open a call with the GSC to confirm there is no other known issue that would explain this.
  
  I have seen issues with redundancy due to the top connector not being properly seated, but I don't recall this symptom/behavior.

  Andre Dicaire

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• hagouda

  

  • 19 Aug 2025 8:52 AM

  In reply to Andre Dicaire:

  Dear All
  Thanks for your response. I've already contacted GSC, they are collecting data and till now we are unable to sort out this issue.
  Thanks again, and I'll revert once it is sorted out.
  Hossam

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• hagouda

  

  • 26 Aug 2025 5:38 PM

  In reply to hagouda:

  Dear ALL
  kindly be informed the the problem was identified by GSC as I need either to downgrade Red. AI/AO cards from ver 1.36 to 1.33 or upgrade Red. AI/AO from 1.36 to 1.38 as mentioned in KBA NK-2400-0016 and KBA 2000-0197.
  This is for your refrance
  Thanks
  Hosssam

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