diff --git a/src/ZB.MOM.WW.MxGateway.Worker.Tests/Probes/AlarmSubtagLiveSmokeTests.cs b/src/ZB.MOM.WW.MxGateway.Worker.Tests/Probes/AlarmSubtagLiveSmokeTests.cs
index 41ff65a..a8b1ad5 100644
--- a/src/ZB.MOM.WW.MxGateway.Worker.Tests/Probes/AlarmSubtagLiveSmokeTests.cs
+++ b/src/ZB.MOM.WW.MxGateway.Worker.Tests/Probes/AlarmSubtagLiveSmokeTests.cs
@@ -288,6 +288,150 @@ public sealed class AlarmSubtagLiveSmokeTests
         Log("CONFIRMED: runtime subtag path resolves and the AckMsg write succeeded.");
     }
 
+    /// <summary>
+    ///     Self-driving full lifecycle test. Drives the alarm by writing its
+    ///     source attribute (<c>TestMachine_001.TestAlarm001</c>) false then
+    ///     true then false, and asserts that <see cref="SubtagAlarmConsumer"/>
+    ///     synthesizes a Raise (after true) and a Clear (after the final false),
+    ///     with an acknowledge (AckMsg write) in between. No external alarm-flip
+    ///     script required. Runs only when
+    ///     <c>MXGATEWAY_RUN_LIVE_MXACCESS_TESTS=1</c>; has a side effect
+    ///     (toggles the live test alarm).
+    /// </summary>
+    [LiveMxAccessFact]
+    public void LiveSelfDriven_RaiseAckClear_SynthesizesTransitions()
+    {
+        Exception? threadException = null;
+        ManualResetEventSlim done = new ManualResetEventSlim(false);
+        Thread thread = new Thread(() =>
+        {
+            try { RunSelfDriven(); }
+            catch (Exception ex) { threadException = ex; }
+            finally { done.Set(); }
+        });
+        thread.IsBackground = false;
+        thread.SetApartmentState(ApartmentState.STA);
+        thread.Start();
+        done.Wait();
+        thread.Join();
+
+        List<string> lines = new List<string>();
+        output.WriteLine(string.Format("Captured {0} log line(s):", log.Count));
+        string? line;
+        while (log.TryDequeue(out line))
+        {
+            output.WriteLine(line);
+            lines.Add(line);
+        }
+
+        string logPath = Environment.GetEnvironmentVariable("PROBE_LOG")
+            ?? System.IO.Path.Combine(System.IO.Path.GetTempPath(), "alarm-subtag-selfdriven.log");
+        try { System.IO.File.WriteAllLines(logPath, lines); }
+        catch (Exception writeEx) { output.WriteLine("self-driven-log write failed: " + writeEx.Message); }
+
+        if (threadException != null)
+        {
+            throw threadException;
+        }
+    }
+
+    private void RunSelfDriven()
+    {
+        // The discrete alarm's source attribute. Writing its boolean value
+        // drives the alarm: true -> in alarm, false -> normal.
+        const string AlarmSourceTag = "TestMachine_001.TestAlarm001";
+
+        Log("=== Self-driven Raise/Ack/Clear lifecycle ===");
+        Log("AlarmFullReference: " + AlarmFullReference);
+        Log("Alarm source tag (driven): " + AlarmSourceTag);
+
+        AlarmSubtagTarget target = new AlarmSubtagTarget
+        {
+            AlarmFullReference = AlarmFullReference,
+            SourceObjectReference = AlarmTagName,
+            ActiveSubtag = PlaceholderActiveSubtag,
+            AckedSubtag = PlaceholderAckedSubtag,
+            AckCommentSubtag = PlaceholderAckCommentSubtag,
+            PrioritySubtag = PlaceholderPrioritySubtag,
+        };
+        List<AlarmSubtagTarget> watchList = new List<AlarmSubtagTarget> { target };
+
+        MxAccessComObjectFactory factory = new MxAccessComObjectFactory();
+        LmxSubtagAlarmSource source = new LmxSubtagAlarmSource(factory, clientName: null);
+        using SubtagAlarmConsumer consumer = new SubtagAlarmConsumer(source, watchList);
+
+        ConcurrentQueue<MxAlarmTransitionEvent> transitions =
+            new ConcurrentQueue<MxAlarmTransitionEvent>();
+        consumer.AlarmTransitionEmitted += (_, e) =>
+        {
+            Log("Transition emitted: " + DescribeTransition(e));
+            transitions.Enqueue(e);
+        };
+
+        // Advise the alarm subtags (InAlarm/Acked/Priority/AckMsg).
+        consumer.Subscribe(string.Format(@"\\{0}\Galaxy!{1}", Environment.MachineName, Group));
+        // Also advise the source attribute so it is an active, writable item
+        // (MXAccess rejects writes to added-but-not-advised items).
+        source.Advise(new List<string> { AlarmSourceTag });
+        Log("Subscribed + advised source. Pumping to activate items ...");
+        PumpFor(TimeSpan.FromSeconds(7));
+
+        // Baseline OFF: drive the source false and drain whatever transitions
+        // result (including any initial Raise if the alarm started active).
+        Log("Driving source = false (baseline OFF) ...");
+        source.Write(AlarmSourceTag, false);
+        PumpFor(TimeSpan.FromSeconds(5));
+        int drained = 0;
+        MxAlarmTransitionEvent? ignored;
+        while (transitions.TryDequeue(out ignored)) { drained++; }
+        Log(string.Format("Drained {0} baseline transition(s).", drained));
+
+        // RAISE: drive the source true.
+        Log("Driving source = true (RAISE) ...");
+        source.Write(AlarmSourceTag, true);
+        MxAlarmTransitionEvent? raiseEvent = WaitForTransitionKind(
+            transitions, AlarmTransitionKind.Raise, RaiseWaitTimeout, "Raise");
+        Assert.NotNull(raiseEvent);
+        Assert.True(raiseEvent!.Record.Degraded, "Subtag-synthesized records must have Degraded=true.");
+        Assert.NotEqual(Guid.Empty, raiseEvent.Record.AlarmGuid);
+        Assert.Equal(MxAlarmStateKind.UnackAlm, raiseEvent.Record.State);
+        Log(string.Format("RAISE confirmed: Guid={0} State={1}", raiseEvent.Record.AlarmGuid, raiseEvent.Record.State));
+
+        // ACK: write the ack-comment subtag.
+        Log("AcknowledgeByName (writes AckMsg) ...");
+        int rc = consumer.AcknowledgeByName(
+            alarmName: AlarmTagName,
+            providerName: Provider,
+            groupName: Group,
+            ackComment: "self-driven-smoke ack",
+            ackOperatorName: Environment.UserName,
+            ackOperatorNode: Environment.MachineName,
+            ackOperatorDomain: Environment.UserDomainName ?? string.Empty,
+            ackOperatorFullName: Environment.UserName);
+        Log(string.Format("AcknowledgeByName -> rc={0}", rc));
+        Assert.Equal(0, rc);
+
+        // CLEAR: drive the source false.
+        Log("Driving source = false (CLEAR) ...");
+        source.Write(AlarmSourceTag, false);
+        MxAlarmTransitionEvent? clearEvent = WaitForTransitionKind(
+            transitions, AlarmTransitionKind.Clear, ClearWaitTimeout, "Clear");
+        Assert.NotNull(clearEvent);
+        Log(string.Format("CLEAR confirmed: State={0}", clearEvent!.Record.State));
+
+        Log("Self-driven lifecycle complete: Raise -> Ack -> Clear all synthesized.");
+    }
+
+    private void PumpFor(TimeSpan duration)
+    {
+        DateTime deadline = DateTime.UtcNow + duration;
+        while (DateTime.UtcNow < deadline)
+        {
+            PumpMessages();
+            Thread.Sleep(100);
+        }
+    }
+
     private void RunSmoke()
     {
         Log(string.Format("AlarmFullReference: {0}", AlarmFullReference));