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Shelve alarms temporarily ​

Shelving temporarily removes selected channels from this runtime's active alarm presentation and sound. Monitoring and logging continue, and alarms return automatically when their shelves expire.

Start a shelf ​

  1. Right-click a channel or group in either alarm pane and choose Shelve this channel… or Shelve this group…. The dialog targets the item you right-clicked. You can also select an item and choose Action → Shelve Alarms….
  2. Choose 15 minutes, 30 minutes, 1 hour, 4 hours, 8 hours, or Custom minutes, Custom hours, or Custom days. Enter a whole number in the selected unit, up to 365 days (8,760 hours or 525,600 minutes). One hour is selected by default.
  3. Enter your Username (up to 120 characters, without spaces or control characters) and a single-line Reason (up to 240 characters), then click Shelve. Both fields are required. Username is entered by the operator; QtALH does not authenticate it.

The timer starts when you apply the action. A group shelves only its currently unshelved descendants; existing shelves keep their own deadlines and reasons. The dialog shows the affected count and retains its displayed target when the main selection changes. Choosing a different target through the context menu replaces the open shelving dialog with a fresh dialog for that target.

Unfiltered views show [Shelved] beside affected channels and shelved counts on their parent groups. Active and unacknowledged filters exclude those channels. Shelved channels do not contribute to alarm counts or sound, including the compact facility indicator.

Review, change, or end shelves ​

Click Shelved: N or choose View → Shelved Alarms…. The list shows each channel's full path, underlying alarm severity, outstanding acknowledgement severity, expiration in local time, countdown, reason, value, and username. The channel tooltip also shows who set the current shelf.

  • Select entries and click Unshelve Selected to restore them immediately.
  • Select one entry and click Change Shelf… to replace its duration and reason. Enter your username again; the previous operator's name is not prefilled. The shelf shows the username of the latest operator to set or change it, and the operation log records the previous username when a shelf is changed.
  • Action → Unshelve Alarms clears every shelf under the selected group, including shelves applied individually.

At expiry, the current alarm presentation returns automatically. A cleared transient can reappear if it still requires acknowledgement. Existing silence settings and beep thresholds apply. Unshelve a channel before acknowledging it; bulk acknowledgement skips shelved channels.

What shelving changes ​

OperationAlarm counts and active listsAcknowledgement stateSound
ShelvingTemporarily excludes selected channelsPreserved under normal alarm/mask rulesSuppressed for selected channels
Timed NoAckUses the existing NoAck mask behaviorChanges acknowledgement requirementsFollows NoAck behavior
SilenceUnchangedUnchangedSuppressed according to the selected silence option

Shelving does not change masks or write ACKS/ACKT. Command hooks and severity output PVs continue to reflect the underlying alarm state. Monitoring, count filtering, and alarm logging continue normally. Other clients are unaffected, even in global mode. Changes from Force PVs, manual masks, and other clients' acknowledgements still apply; expiry does not override Disable or Cancel.

Reloads and runtime lifetime ​

Successful reloads in the same runtime retain shelves, their usernames, and their original deadlines for uniquely matching full channel paths. Removed, renamed, moved, or ambiguous entries lose their shelves; new channels start unshelved. Failed reloads preserve the current state. Local outstanding latches on matched shelved channels survive reload; global acknowledgement state follows fresh IOC updates.

Shelves are not exported by Save As, written to configuration files, or restored in a new runtime. Stopping the runtime clears them. Hiding the main window while the compact runtime remains open leaves them active. Expiration uses the system wall clock and is checked on the next engine tick, including after suspend.

The operator log records usernames, reasons, and deadlines for shelving, changes, early unshelving, expiry, and reload-related removal. Existing logging-disable options still apply; persistent attribution requires operation logging to be enabled. See alarm logs and silencing and filters for related workflows.