dohertj2/lmxopcua
1
0
Fork 0
Code Issues 2 Pull Requests 1 Actions Packages Projects Releases Wiki Activity

docs(alarms): note native-alarm severity-bucket snapping

Browse Source
This commit is contained in:
Joseph Doherty
2026-06-14 22:41:57 -04:00
parent 51cda2c744
commit 49d98cba31
1 changed files with 29 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
docs/ScriptedAlarms.md
+29
View File
@@ -142,6 +142,35 @@ ObjectType. `severity` seeds the condition's initial severity at materialisation
the driver's live alarm events may carry a different severity that overrides it at
runtime.
#### Severity mapping
The authored `severity` (1–1000) seeds the OPC UA condition node at materialisation
time. On the **first native transition** the value snaps to one of four fixed buckets
via `NativeAlarmProjector.MapSeverity`:
| `AlarmSeverity` enum | Projected value |
|---|---|
| `Low` | 200 |
| `Medium` | 500 |
| `High` | 700 |
| `Critical` | 900 |
| *(default/unspecified)* | 500 |
That projected integer is then mapped to the OPC UA SDK `EventSeverity` enum
by `OtOpcUaNodeManager.MapSeverity` on each `AlarmStateUpdate` write:
| Projected value range | `EventSeverity` |
|---|---|
| < 200 | `Low` |
| 200 – 399 | `MediumLow` |
| 400 – 599 | `Medium` |
| 600 – 799 | `MediumHigh` |
| ≥ 800 | `High` |
Consequently the four authored buckets land as: Low→`MediumLow`, Medium→`Medium`,
High→`MediumHigh`, Critical→`High`. The authored `severity` field has no effect after
the first transition.
### Runtime flow
The driver's live `IAlarmSource.OnAlarmEvent` is the sole input. Transition kinds