diff --git a/src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/MxGatewayAlarmMapper.cs b/src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/MxGatewayAlarmMapper.cs
index e3a7b7c5..c91d6765 100644
--- a/src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/MxGatewayAlarmMapper.cs
+++ b/src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/MxGatewayAlarmMapper.cs
@@ -86,7 +86,14 @@ public static class MxGatewayAlarmMapper
     /// <param name="body">The gateway alarm transition event proto message to map.</param>
     /// <returns>The protocol-neutral <see cref="NativeAlarmTransition"/>.</returns>
     public static NativeAlarmTransition MapTransition(OnAlarmTransitionEvent body) => new(
-        SourceReference: body.AlarmFullReference,
+        // Identify the condition by the object-relative reference (e.g.
+        // "Z28061.HeartbeatTimeoutAlarm") rather than the gateway's full provider
+        // reference ("Galaxy!<area>.<object>.<alarm>"). The area is preserved in
+        // Category; the object reference is globally unique within the galaxy and
+        // is the form operators expect. Falls back to the full reference only if
+        // the gateway omits the object reference.
+        SourceReference: string.IsNullOrEmpty(body.SourceObjectReference)
+            ? body.AlarmFullReference : body.SourceObjectReference,
         SourceObjectReference: body.SourceObjectReference,
         AlarmTypeName: body.AlarmTypeName,
         Kind: MapKind(body.TransitionKind),
@@ -112,7 +119,10 @@ public static class MxGatewayAlarmMapper
     /// <param name="snapshot">The active alarm snapshot proto message to map.</param>
     /// <returns>A <see cref="NativeAlarmTransition"/> with <c>AlarmTransitionKind.Snapshot</c>.</returns>
     public static NativeAlarmTransition MapSnapshot(ActiveAlarmSnapshot snapshot) => new(
-        SourceReference: snapshot.AlarmFullReference,
+        // See MapTransition: identify by the object-relative reference, not the
+        // full "Galaxy!<area>.<object>.<alarm>" provider reference.
+        SourceReference: string.IsNullOrEmpty(snapshot.SourceObjectReference)
+            ? snapshot.AlarmFullReference : snapshot.SourceObjectReference,
         SourceObjectReference: snapshot.SourceObjectReference,
         AlarmTypeName: snapshot.AlarmTypeName,
         Kind: AlarmTransitionKind.Snapshot,
diff --git a/tests/ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests/MxGatewayAlarmMapperTests.cs b/tests/ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests/MxGatewayAlarmMapperTests.cs
index 5f8eaf3e..438ffbdc 100644
--- a/tests/ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests/MxGatewayAlarmMapperTests.cs
+++ b/tests/ZB.MOM.WW.ScadaBridge.DataConnectionLayer.Tests/MxGatewayAlarmMapperTests.cs
@@ -65,6 +65,54 @@ public class MxGatewayAlarmMapperTests
         Assert.Equal(1000, t.Condition.Severity);
     }
 
+    [Fact]
+    public void SourceReference_IsObjectRelative_NotFullProviderReference()
+    {
+        // The condition identity surfaced upward is the object-relative reference
+        // (e.g. "Z28061.HeartbeatTimeoutAlarm"), not the gateway's full provider
+        // reference ("Galaxy!<area>.<object>.<alarm>"). Area lives in Category.
+        var snap = new ActiveAlarmSnapshot
+        {
+            AlarmFullReference = "Galaxy!CVDAisle_1.Z28061.HeartbeatTimeoutAlarm",
+            SourceObjectReference = "Z28061.HeartbeatTimeoutAlarm",
+            AlarmTypeName = "Syst",
+            Category = "CVDAisle_1",
+            CurrentState = ProtoConditionState.Active,
+            Severity = 400
+        };
+        var ev = new OnAlarmTransitionEvent
+        {
+            AlarmFullReference = "Galaxy!CVDAisle_1.Z28061.HeartbeatTimeoutAlarm",
+            SourceObjectReference = "Z28061.HeartbeatTimeoutAlarm",
+            AlarmTypeName = "Syst",
+            TransitionKind = ProtoTransitionKind.Raise,
+            Severity = 400
+        };
+
+        var snapT = MxGatewayAlarmMapper.MapSnapshot(snap);
+        var liveT = MxGatewayAlarmMapper.MapTransition(ev);
+
+        Assert.Equal("Z28061.HeartbeatTimeoutAlarm", snapT.SourceReference);
+        Assert.Equal("Z28061.HeartbeatTimeoutAlarm", liveT.SourceReference);
+        Assert.Equal("CVDAisle_1", snapT.Category);
+    }
+
+    [Fact]
+    public void SourceReference_FallsBackToFullReference_WhenObjectReferenceEmpty()
+    {
+        var snap = new ActiveAlarmSnapshot
+        {
+            AlarmFullReference = "Galaxy!Area.Obj.Alarm",
+            SourceObjectReference = "",
+            CurrentState = ProtoConditionState.Active,
+            Severity = 100
+        };
+
+        var t = MxGatewayAlarmMapper.MapSnapshot(snap);
+
+        Assert.Equal("Galaxy!Area.Obj.Alarm", t.SourceReference);
+    }
+
     // ── CurrentValue / LimitValue (M2.13 / #27) ──────────────────────────────
 
     [Fact]