Surface native (Galaxy/MxGateway) alarms by their object-relative reference
(e.g. "Z28061.HeartbeatTimeoutAlarm") instead of the gateway's full provider
reference ("Galaxy!<area>.<object>.<alarm>"). The area is already preserved in
Category and the object reference is globally unique within the galaxy, so the
full provider prefix added only noise to the alarm identity operators see.
MxGatewayAlarmMapper.MapTransition/MapSnapshot now set SourceReference from
SourceObjectReference, falling back to AlarmFullReference only when the gateway
omits the object reference. +2 mapper tests; full DCL suite green (158).
OPC UA (RealOpcUaClient):
- Append 5 new SelectClauses at indices 13–17 (never renumber 0–12):
- 13: AlarmConditionType/ActiveState/TransitionTime → OriginalRaiseTime
- 14–17: LimitAlarmType HighHighLimit/HighLimit/LowLimit/LowLowLimit → LimitValue
- New OpcUaAlarmMapper.PickLimitValue helper: first non-null in HiHi→Hi→Lo→LoLo
priority order, InvariantCulture-formatted; empty string for non-limit alarm types.
- HandleAlarmEvent reads new indices with fields.Count > N guards; hard minimum (6)
unchanged so base ConditionType events still process without the limit fields.
- Document unavailable-by-protocol fields (Category, Description, OperatorUser,
CurrentValue) inline in BuildAlarmEventFilter and HandleAlarmEvent.
MxGateway (MxGatewayAlarmMapper):
- MapTransition: CurrentValue and LimitValue now populated via MxValueToString
(uses MxValueExtensions.ToClrValue + InvariantCulture) from OnAlarmTransitionEvent
proto fields current_value/limit_value.
- MapSnapshot: same — populated from ActiveAlarmSnapshot.current_value/limit_value.
- MxValueToString helper (internal): null-safe MxValue → string conversion.
Tests (17 new, 40 total pass):
- OpcUaAlarmMapperTests: PickLimitValue priority, InvariantCulture, all-null case.
- MxGatewayAlarmMapperTests: CurrentValue/LimitValue populate from double/string
MxValue; absent fields yield empty strings.
- RealOpcUaClientAlarmFilterTests: index alignment assertions (count=18, per-index
TypeDefinitionId+BrowsePath), regression guard on existing indices 0–12.
Adds IAlarmSubscribableConnection to MxGatewayDataConnection (shared session-less
feed, ref-counted), IMxGatewayClient.RunAlarmStreamAsync over the package
StreamAlarmsAsync with internal reconnect, and MxGatewayAlarmMapper
(AlarmFeedMessage/OnAlarmTransitionEvent -> NativeAlarmTransition). Behavior
verified against a live gateway in Task 28; mapper unit-tested.
Joseph Doherty