This is a list of all comments for HD-DEN-15306-1.

Review Summary: No summary


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File: firmware/App/Services/AlarmMgmt.c
Revision Comment by Sean Nash on 19 May 2023, 09:47 
https://devapps.diality.us/cru/HD-DEN-15306-1#c17638

  This doesn't seem like a fix to root cause - may not work if
  user clears alarm quickly.  
  Suggest looking at valve driver where alarm 62 is
  detected/triggered and maybe zeroing positionOutOfRangeCounter
  (reset 1 sec persistence) if AC power is out.  That way, when
  AC is restored, valves will have a whole second to get where
  they're supposed to be before alarm is triggered.

  Reply by jtaylor on 19 May 2023, 17:52
  > The root cause is that abnormal AC power loss on the HD
  > causes abnormal operating conditions and spurious errors. The
  > valves return to position after the alarm is cleared, not
  > when AC returns. The timer gives a ten-second window
  > following removing the power fail signal and the alarm
  > condition, where the alarm block is active. The original
  > block used the alarms alone, we changed to the CPLD power
  > loss detection - which returns with the return of AC.
  > Clearing the alarms late means removing the block before the
  > valves return to normal operation. 
  > 
  > I think there are two approaches. We already have distributed
  > failsafe that is entered on power fail, which we recover from
  > after the alarm is cleared.
  > 1. Create a pervasive state that affects every operating
  > mode, allowing transitions to "safe" states during alarms,
  > then back to the original operating state. The safe state
  > would not register errors until after the transition back to
  > normal operation.
  > 2. Block errors until both AC is returned and the alarm is
  > cleared when normal operation is restored.
  > 
  > The second approach is much simpler and addresses the root
  > problem: odd control configurations resulting from having
  > alarms with conflicting controls. In this case, the secondary
  > alarms are spurious since they result from the valves
  > dropping into a safe position, for instance, on the loss of
  > AC. We also have a handful of other errors that occur under
  > these conditions, fan speed, for instance, as well as valve
  > positions,

  Reply by jtaylor on 22 May 2023, 11:55
  > Added alarm 62 detection disable as suggested.

    Reply by Sean Nash on 23 May 2023, 08:36
    > So then can we remove power loss alarm active checks from
    > this condition (just keep the cpld power loss check as
    > before)?

      Reply by jtaylor on 24 May 2023, 09:05
      > If we think that this is the only spurious alarm that may
      > occur with power loss. We know fan rpm also occurs, but
      > the fans do recover when AC returns. Comm errors have
      > occurred, but they seem rare now; it's unclear whether
      > they stop with AC returning or the operational state.
      > Would we expect other operational impacts of operating
      > from battery, or the loss and return of AC? Battery
      > alarms, etc.?
      > 
      > The block timer runs from the time the condition clears
      > in alarm management (cpld flag, or flag plus alarm
      > state). If alarms are not included here, the timer may
      > (probably will) time out with the alarm still active and
      > the valves still improperly positioned. The valve
      > position error will occur immediately after clearing the
      > alarms, even with the alarms status checked in valves.
      > The timer could be relocated to valves, but that doesn't
      > take care of other sources of alarms after power
      > recovery.

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File: firmware/App/Controllers/Valves.c
Revision Comment by Sean Nash on 23 May 2023, 08:35 
https://devapps.diality.us/cru/HD-DEN-15306-1#c17643

  Do we need the alarm active checks?  Isn't power loss check
  sufficient?

  Reply by jtaylor on 24 May 2023, 09:01
  > The valves are not returned to their target position until
  > the alarm is cleared.  I could make a broader change, but is
  > that what you're suggesting?


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ID: HD-DEN-15306-1 https://devapps.diality.us/cru/HD-DEN-15306-1

Title: HD-DEN-15306_HD Fault Valve Position Alarm After Restoring AC Power
Statement of Objectives:


State: Closed

Summary: 

Author: jtaylor
Moderator: jtaylor
Reviewers: (6 active, 0 completed*)
     Sean Nash
     Michael Garthwaite
     wbracken
     Dara Navaei
     dcox
     Steve Jarpe