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Alarm acknowledge status following unmasking

Hi,

I am working on some dynamic alarm masking and investigating the masking and unmasking behavior. The currently functionality on the project following alarm unmasking is -

- If inactive, the alarm does not appear on the alarm list. This is correct and what is expected.

- If active, the alarm comes back into the alarm list time stamped with current time and Acknowledged status - this is an issue as there is a high chance that the operator could miss it as it is already Acknowleged!

I was wondering if anyone has any previous experience/suggestions about dealing with this behavior and how the logic could be amended/edited to make sure the alarm, if still active, comes back as Unacknowledged following unmasking?

Thanks for your help.

yashdongre
  • Matt Stoner

    You have two options and maybe only one if you also want the horn to become active again as well as alarm being unacknowledged.

    1. Change the alarm to look at a new bit that is the result of the existing alarm bit (i.e. PID1/LO_ACT) AND'ed with the Alarm being Suppressed/OOS (for v13 only). This will activate the Horn when it's unsuppressed because it will be seen as a new alarm by the system.
      1. v13 - '^/NEW_LO_ACT.CV' := '^/PID1/LO_ACT.CV' AND ('^/LO_ALM.OPSUP' OR '^/LO_ALM.OOS);
      2. prior v13 - '^/NEW_LO_ACT.CV' := '^/PID1/LO_ACT.CV' AND '^/LO_ALM.OPSUP';

    2. Put logic in your modules to look at the alarm suppression and if it was previously on and then it turned off (One shot action), you would set the alarm parameter field NALM to alarm result. (i.e. '^/LO_ALM.NALM' := '^/PID1/LO_ACT.CV';)
      1. v13
        If ((LAST_LO_SUP <> '^/LO_ALM.OPSUP') OR (LAST_LO_OOS <> '^/LO_ALM.OOS')) AND ('^/LO_ALM.OPSUP' = FALSE) AND ('^/LO_ALM.OOS' = FALSE)
        Then
            '^/LO_ALM.NALM' := '^/PID1/LO_ACT.CV';
        Endif;
        LAST_LO_SUP := '^/LO_ALM.OPSUP';
        LAST_LO_OOS := '^/LO_ALM.OOS';
      2. prior v13
        If (LAST_LO_SUP <> '^/LO_ALM.OPSUP') AND ('^/LO_ALM.OPSUP' = FALSE)
        Then
            '^/LO_ALM.NALM' := '^/PID1/LO_ACT.CV';
        Endif;
        LAST_LO_SUP := '^/LO_ALM.OPSUP';

    Either case requires that you change all the modules/alarms and then download unfortunately.

  • yashdongre

    In reply to Matt Stoner:

    That's really useful, thanks for the help!
  • Hisham
    Is it only happening for a specific single alarm ? or it is happening for all "blue" or "red" priority alarm for example! if it is for groups of alarms with the same priority then you have to uncheck "Auto Acknowledge New Alarms " option for the specific priority group! else you have to follow the steps mentioned by @Matt Stoner

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