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3.4.3 Alarms

Alarms watch a device + channel on every poll. They are evaluated by the ingest loader (and also if an admin posts a reading through the application).

Everyone can see rules and history. Only admins can create or delete rules.

Open Alarms in the top nav.

Tabs

Tab Who Purpose
Rules Everyone Configured alarms and live state
History Everyone Raised / cleared events for one device
New alarm Admin Create a rule

Rule States (Rules Tab)

Each rule shows device, channel, condition summary, and hold time.

Alarms — Rules tab

Badge Meaning
latched Alarm is raised and stays raised until the condition clears
pending Condition is true, but hold time has not elapsed yet
inactive Rule is turned off. Not evaluated

Latching is intentional: a brief recovery does not hide a real event until the value is clearly back to normal.

History Tab

Pick a device. Events list local time, raised or cleared, message, and the sample value.

Alarms — History tab

Creating a Rule (Admin)

Alarms → New alarm

Alarms — New alarm form

  1. Device and channel
  2. A short name (shown on the rules list)
  3. Condition (below)
  4. Thresholds as prompted
  5. Hold time (minutes) — how long the condition must stay true before the alarm raises and latches. 0 means the next poll can latch immediately
  6. Create alarm

Delete from the Rules list (admin). There is no edit form in the UI; delete and recreate if the setpoint is wrong.

Condition Types

Above / Below / Between

Classic setpoints on the chosen channel’s value (same units as the channel).

Condition Raises When
above value > threshold
below value < threshold
between threshold ≤ value ≤ high threshold

Example: flow below 1 for 30 minutes → condition below, threshold 1, hold 30.

Drop While Flowing (Air Suck)

Meant for flow rate (m³/h), not cumulative litres.

The evaluator learns a baseline (normal pumping rate). It raises when flow is still above a floor (so the pump is not merely off / switching) but has fallen by at least the drop amount below that baseline.

Field in the Form Typical Starting Point
Drop amount 0.5 m³/h
Minimum flowing rate 0.3 m³/h
Hold time 1–2 minutes so pump changeovers do not latch

Behaviour in short:

  • Flow below the floor: Treated as off / switchover. The hold timer resets. An already-latched alarm is not cleared by a near-zero dip alone
  • Baseline: Rises fairly quickly with higher flow, and falls only slowly, so a real drop is measured against the pre-drop rate
  • While pending: Baseline is frozen
  • Clear: Uses hysteresis (about 65% of the drop size) so the latch can release on a genuine recovery without requiring an exact return to the old peak

Suggested Starting Recipe

Drop 0.5, floor 0.3, hold 2 minutes (also shown on the form).

When Evaluation Runs

  • Every successful channel poll in the loader, even if the reading was a duplicate
  • Admin insert: When an admin inserts a reading through the application

If the loader is down, alarms will not change state until polling resumes.

Version Control
Version Date Description
1.0 2026-10-18 Initial Release
1.1 2026-10-20 Style guide compliance — list labels and tip admonition

Next Review Date: 2027-04-20