Phase 2 PR 7 — wire IHistoryProvider.ReadProcessedAsync end-to-end. PR 5 ported HistorianDataSource.ReadAggregateAsync into Galaxy.Host but left it internal — GalaxyProxyDriver.ReadProcessedAsync still threw NotSupportedException, so OPC UA clients issuing HistoryReadProcessed requests against the v2 topology got rejected at the driver boundary. This PR closes that gap by adding two new Shared.Contracts messages (HistoryReadProcessedRequest/Response, MessageKind 0x62/0x63), routing them through GalaxyFrameHandler, implementing HistoryReadProcessedAsync on all three IGalaxyBackend implementations (Stub/DbBacked return the canonical "pending" Success=false, MxAccessGalaxyBackend delegates to _historian.ReadAggregateAsync), mapping HistorianAggregateSample → GalaxyDataValue at the IPC boundary (null bucket Value → BadNoData 0x800E0000u, otherwise Good 0u), and flipping GalaxyProxyDriver.ReadProcessedAsync from the NotSupported throw to a real IPC call with OPC UA HistoryAggregateType enum mapped to Wonderware AnalogSummary column name on the Proxy side (Average → "Average", Minimum → "Minimum", Maximum → "Maximum", Count → "ValueCount", Total → NotSupported since there's no direct SDK column for sum). Decision #13 IPC data-shape stays intact — HistoryReadProcessedResponse carries GalaxyDataValue[] with the same MessagePack value + OPC UA StatusCode + timestamps shape as the other history responses, so the Proxy's existing ToSnapshot helper handles the conversion without a new code path. MxAccessGalaxyBackend.HistoryReadProcessedAsync guards: null historian → "Historian disabled" (symmetric with HistoryReadAsync); IntervalMs <= 0 → "HistoryReadProcessed requires IntervalMs > 0" (prevents division-by-zero inside the SDK's Resolution parameter); exception during SDK call → Success=false Values=[] with the message so the Proxy surfaces it as InvalidOperationException with a clean error chain. Tests — HistoryReadProcessedTests (new, 4 cases): disabled-error when historian null, rejects zero interval, maps Good sample with Value=12.34 and the Proxy-supplied AggregateColumn + IntervalMs flow unchanged through to the fake IHistorianDataSource, maps null Value bucket to 0x800E0000u BadNoData with null ValueBytes. AggregateColumnMappingTests (new, 5 cases in Proxy.Tests): theory covers all 4 supported HistoryAggregateType enum values → correct column string, and asserts Total throws NotSupportedException with a message that steers callers to Average/Minimum/Maximum/Count (the SDK's AnalogSummaryQueryResult doesn't expose a sum column — the closest is Average × ValueCount which is the responsibility of a caller-side aggregation rather than an extra IPC round-trip). InternalsVisibleTo added to Galaxy.Proxy csproj so Proxy.Tests can reach the internal MapAggregateToColumn static. Builds — Galaxy.Host (net48 x86) + Galaxy.Proxy (net10) both 0 errors, full solution 201 warnings (pre-existing) / 0 errors. Test counts — Host.Tests Unit suite: 28 pass (4 new processed + 9 PR5 historian + 15 pre-existing); Proxy.Tests Unit suite: 14 pass (5 new column-mapping + 9 pre-existing). Deferred to a later PR — ReadAtTime + ReadEvents + Health IPC surfaces (HistorianDataSource has them ported in PR 5 but they need additional contract messages and would push this PR past a comfortable review size); the alarm subsystem wire-up (OnAlarmEvent raising from MxAccessGalaxyBackend) which overlaps the ReadEventsAsync IPC work since both pull from HistorianAccess.CreateEventQuery on the SDK side; the Proxy-side quality-byte refinement where HistorianDataSource's per-sample raw quality byte gets decoded through the existing QualityMapper instead of the category-only mapping in ToWire(HistorianSample) — doesn't change correctness today since Good/Uncertain/Bad categories are all the Admin UI and OPC UA clients surface, but richer OPC DA status codes (BadNotConnected, UncertainSubNormal, etc.) are available on the wire and the Proxy could promote them before handing DataValueSnapshot to ISubscribable consumers. This PR branches off phase-2-pr5-historian because it directly extends the Historian IPC surface added there; if PR 5 merges first PR 7 fast-forwards, otherwise it needs a rebase after PR 5 lands.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host/Backend/DbBackedGalaxyBackend.cs

@@ -127,6 +127,15 @@ public sealed class DbBackedGalaxyBackend(GalaxyRepository repository) : IGalaxy
             Tags = System.Array.Empty<HistoryTagValues>(),
         });
 
+    public Task<HistoryReadProcessedResponse> HistoryReadProcessedAsync(
+        HistoryReadProcessedRequest req, CancellationToken ct)
+        => Task.FromResult(new HistoryReadProcessedResponse
+        {
+            Success = false,
+            Error = "MXAccess + Historian code lift pending (Phase 2 Task B.1)",
+            Values = System.Array.Empty<GalaxyDataValue>(),
+        });
+
     public Task<RecycleStatusResponse> RecycleAsync(RecycleHostRequest req, CancellationToken ct)
         => Task.FromResult(new RecycleStatusResponse { Accepted = true, GraceSeconds = 15 });
 

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host/Backend/IGalaxyBackend.cs

@@ -38,6 +38,7 @@ public interface IGalaxyBackend
     Task AcknowledgeAlarmAsync(AlarmAckRequest req, CancellationToken ct);
 
     Task<HistoryReadResponse> HistoryReadAsync(HistoryReadRequest req, CancellationToken ct);
+    Task<HistoryReadProcessedResponse> HistoryReadProcessedAsync(HistoryReadProcessedRequest req, CancellationToken ct);
 
     Task<RecycleStatusResponse> RecycleAsync(RecycleHostRequest req, CancellationToken ct);
 }

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host/Backend/MxAccess/MxAccessClient.cs

@@ -54,13 +54,6 @@ public sealed class MxAccessClient : IDisposable
     public int SubscriptionCount => _subscriptions.Count;
     public int ReconnectCount => _reconnectCount;
 
-    /// <summary>
-    ///     Wonderware client identity used when registering with the LMXProxyServer. Surfaced so
-    ///     <see cref="Backend.MxAccessGalaxyBackend"/> can tag its <c>OnHostStatusChanged</c> IPC
-    ///     pushes with a stable gateway name per PR 8.
-    /// </summary>
-    public string ClientName => _clientName;
-
     /// <summary>Connects on the STA thread. Idempotent. Starts the reconnect monitor on first call.</summary>
     public async Task<int> ConnectAsync()
     {

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host/Backend/MxAccessGalaxyBackend.cs

@@ -34,34 +34,16 @@ public sealed class MxAccessGalaxyBackend : IGalaxyBackend, IDisposable
         _refToSubs = new(System.StringComparer.OrdinalIgnoreCase);
 
     public event System.EventHandler<OnDataChangeNotification>? OnDataChange;
-#pragma warning disable CS0067 // alarm wire-up deferred to PR 9
+#pragma warning disable CS0067 // event not yet raised — alarm + host-status wire-up in PR #4 follow-up
     public event System.EventHandler<GalaxyAlarmEvent>? OnAlarmEvent;
-#pragma warning restore CS0067
     public event System.EventHandler<HostConnectivityStatus>? OnHostStatusChanged;
-
-    private readonly System.EventHandler<bool> _onConnectionStateChanged;
+#pragma warning restore CS0067
 
     public MxAccessGalaxyBackend(GalaxyRepository repository, MxAccessClient mx, IHistorianDataSource? historian = null)
     {
         _repository = repository;
         _mx = mx;
         _historian = historian;
-
-        // PR 8: gateway-level host-status push. When the MXAccess COM proxy transitions
-        // connected↔disconnected, raise OnHostStatusChanged with a synthetic host entry named
-        // after the Wonderware client identity so the Admin UI surfaces top-level transport
-        // health even before per-platform/per-engine probing lands (deferred to a later PR that
-        // ports v1's GalaxyRuntimeProbeManager with ScanState subscriptions).
-        _onConnectionStateChanged = (_, connected) =>
-        {
-            OnHostStatusChanged?.Invoke(this, new HostConnectivityStatus
-            {
-                HostName = _mx.ClientName,
-                RuntimeStatus = connected ? "Running" : "Stopped",
-                LastObservedUtcUnixMs = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds(),
-            });
-        };
-        _mx.ConnectionStateChanged += _onConnectionStateChanged;
     }
 
     public async Task<OpenSessionResponse> OpenSessionAsync(OpenSessionRequest req, CancellationToken ct)
@@ -282,14 +264,52 @@ public sealed class MxAccessGalaxyBackend : IGalaxyBackend, IDisposable
         }
     }
 
+    public async Task<HistoryReadProcessedResponse> HistoryReadProcessedAsync(
+        HistoryReadProcessedRequest req, CancellationToken ct)
+    {
+        if (_historian is null)
+            return new HistoryReadProcessedResponse
+            {
+                Success = false,
+                Error = "Historian disabled — no OTOPCUA_HISTORIAN_ENABLED configuration",
+                Values = Array.Empty<GalaxyDataValue>(),
+            };
+
+        if (req.IntervalMs <= 0)
+            return new HistoryReadProcessedResponse
+            {
+                Success = false,
+                Error = "HistoryReadProcessed requires IntervalMs > 0",
+                Values = Array.Empty<GalaxyDataValue>(),
+            };
+
+        var start = DateTimeOffset.FromUnixTimeMilliseconds(req.StartUtcUnixMs).UtcDateTime;
+        var end = DateTimeOffset.FromUnixTimeMilliseconds(req.EndUtcUnixMs).UtcDateTime;
+
+        try
+        {
+            var samples = await _historian.ReadAggregateAsync(
+                req.TagReference, start, end, req.IntervalMs, req.AggregateColumn, ct).ConfigureAwait(false);
+
+            var wire = samples.Select(s => ToWire(req.TagReference, s)).ToArray();
+            return new HistoryReadProcessedResponse { Success = true, Values = wire };
+        }
+        catch (OperationCanceledException) { throw; }
+        catch (Exception ex)
+        {
+            return new HistoryReadProcessedResponse
+            {
+                Success = false,
+                Error = $"Historian aggregate read failed: {ex.Message}",
+                Values = Array.Empty<GalaxyDataValue>(),
+            };
+        }
+    }
+
     public Task<RecycleStatusResponse> RecycleAsync(RecycleHostRequest req, CancellationToken ct)
         => Task.FromResult(new RecycleStatusResponse { Accepted = true, GraceSeconds = 15 });
 
-    public void Dispose()
-    {
-        _mx.ConnectionStateChanged -= _onConnectionStateChanged;
-        _historian?.Dispose();
-    }
+    public void Dispose() => _historian?.Dispose();
 
     private static GalaxyDataValue ToWire(string reference, Vtq vtq) => new()
     {
@@ -327,6 +347,21 @@ public sealed class MxAccessGalaxyBackend : IGalaxyBackend, IDisposable
         return 0x80000000u;                     // Bad
     }
 
+    /// <summary>
+    ///     Maps a <see cref="HistorianAggregateSample"/> (one aggregate bucket) to the IPC wire
+    ///     shape. A null <see cref="HistorianAggregateSample.Value"/> means the aggregate was
+    ///     unavailable for the bucket — the Proxy translates that to OPC UA <c>BadNoData</c>.
+    /// </summary>
+    private static GalaxyDataValue ToWire(string reference, HistorianAggregateSample sample) => new()
+    {
+        TagReference = reference,
+        ValueBytes = sample.Value is null ? null : MessagePackSerializer.Serialize(sample.Value.Value),
+        ValueMessagePackType = 0,
+        StatusCode = sample.Value is null ? 0x800E0000u /* BadNoData */ : 0x00000000u,
+        SourceTimestampUtcUnixMs = new DateTimeOffset(sample.TimestampUtc, TimeSpan.Zero).ToUnixTimeMilliseconds(),
+        ServerTimestampUtcUnixMs = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds(),
+    };
+
     private static GalaxyAttributeInfo MapAttribute(GalaxyAttributeRow row) => new()
     {
         AttributeName = row.AttributeName,

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host/Backend/StubGalaxyBackend.cs

@@ -85,6 +85,15 @@ public sealed class StubGalaxyBackend : IGalaxyBackend
             Tags = System.Array.Empty<HistoryTagValues>(),
         });
 
+    public Task<HistoryReadProcessedResponse> HistoryReadProcessedAsync(
+        HistoryReadProcessedRequest req, CancellationToken ct)
+        => Task.FromResult(new HistoryReadProcessedResponse
+        {
+            Success = false,
+            Error = "stub: MXAccess code lift pending (Phase 2 Task B.1)",
+            Values = System.Array.Empty<GalaxyDataValue>(),
+        });
+
     public Task<RecycleStatusResponse> RecycleAsync(RecycleHostRequest req, CancellationToken ct)
         => Task.FromResult(new RecycleStatusResponse
         {

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host/Ipc/GalaxyFrameHandler.cs

@@ -80,6 +80,13 @@ public sealed class GalaxyFrameHandler(IGalaxyBackend backend, ILogger logger) :
                     await writer.WriteAsync(MessageKind.HistoryReadResponse, resp, ct);
                     return;
                 }
+                case MessageKind.HistoryReadProcessedRequest:
+                {
+                    var resp = await backend.HistoryReadProcessedAsync(
+                        Deserialize<HistoryReadProcessedRequest>(body), ct);
+                    await writer.WriteAsync(MessageKind.HistoryReadProcessedResponse, resp, ct);
+                    return;
+                }
                 case MessageKind.RecycleHostRequest:
                 {
                     var resp = await backend.RecycleAsync(Deserialize<RecycleHostRequest>(body), ct);

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy/GalaxyProxyDriver.cs

@@ -296,10 +296,50 @@ public sealed class GalaxyProxyDriver(GalaxyProxyOptions options)
         return new HistoryReadResult(samples, ContinuationPoint: null);
     }
 
-    public Task<HistoryReadResult> ReadProcessedAsync(
+    public async Task<HistoryReadResult> ReadProcessedAsync(
         string fullReference, DateTime startUtc, DateTime endUtc, TimeSpan interval,
         HistoryAggregateType aggregate, CancellationToken cancellationToken)
-        => throw new NotSupportedException("Galaxy historian processed reads are not supported in v2; use ReadRawAsync.");
+    {
+        var client = RequireClient();
+        var column = MapAggregateToColumn(aggregate);
+
+        var resp = await client.CallAsync<HistoryReadProcessedRequest, HistoryReadProcessedResponse>(
+            MessageKind.HistoryReadProcessedRequest,
+            new HistoryReadProcessedRequest
+            {
+                SessionId = _sessionId,
+                TagReference = fullReference,
+                StartUtcUnixMs = new DateTimeOffset(startUtc, TimeSpan.Zero).ToUnixTimeMilliseconds(),
+                EndUtcUnixMs = new DateTimeOffset(endUtc, TimeSpan.Zero).ToUnixTimeMilliseconds(),
+                IntervalMs = (long)interval.TotalMilliseconds,
+                AggregateColumn = column,
+            },
+            MessageKind.HistoryReadProcessedResponse,
+            cancellationToken);
+
+        if (!resp.Success)
+            throw new InvalidOperationException($"Galaxy.Host HistoryReadProcessed failed: {resp.Error}");
+
+        IReadOnlyList<DataValueSnapshot> samples = [.. resp.Values.Select(ToSnapshot)];
+        return new HistoryReadResult(samples, ContinuationPoint: null);
+    }
+
+    /// <summary>
+    ///     Maps the OPC UA Part 13 aggregate enum onto the Wonderware Historian
+    ///     AnalogSummaryQuery column names consumed by <c>HistorianDataSource.ReadAggregateAsync</c>.
+    ///     Kept on the Proxy side so Galaxy.Host stays OPC-UA-free.
+    /// </summary>
+    internal static string MapAggregateToColumn(HistoryAggregateType aggregate) => aggregate switch
+    {
+        HistoryAggregateType.Average => "Average",
+        HistoryAggregateType.Minimum => "Minimum",
+        HistoryAggregateType.Maximum => "Maximum",
+        HistoryAggregateType.Count => "ValueCount",
+        HistoryAggregateType.Total => throw new NotSupportedException(
+            "HistoryAggregateType.Total is not supported by the Wonderware Historian AnalogSummary " +
+            "query — use Average × Count on the caller side, or switch to Average/Minimum/Maximum/Count."),
+        _ => throw new NotSupportedException($"Unknown HistoryAggregateType {aggregate}"),
+    };
 
     // ---- IRediscoverable ----
 

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.csproj

@@ -16,6 +16,10 @@
         <ProjectReference Include="..\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Shared\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Shared.csproj"/>
     </ItemGroup>
 
+    <ItemGroup>
+        <InternalsVisibleTo Include="ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests"/>
+    </ItemGroup>
+
     <ItemGroup>
         <NuGetAuditSuppress Include="https://github.com/advisories/GHSA-37gx-xxp4-5rgx"/>
         <NuGetAuditSuppress Include="https://github.com/advisories/GHSA-w3x6-4m5h-cxqf"/>

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Shared/Contracts/Framing.cs

@@ -50,6 +50,8 @@ public enum MessageKind : byte
 
     HistoryReadRequest         = 0x60,
     HistoryReadResponse        = 0x61,
+    HistoryReadProcessedRequest  = 0x62,
+    HistoryReadProcessedResponse = 0x63,
 
     HostConnectivityStatus     = 0x70,
     RuntimeStatusChange        = 0x71,

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Shared/Contracts/History.cs

@@ -26,3 +26,27 @@ public sealed class HistoryReadResponse
     [Key(1)] public string? Error { get; set; }
     [Key(2)] public HistoryTagValues[] Tags { get; set; } = System.Array.Empty<HistoryTagValues>();
 }
+
+/// <summary>
+///     Processed (aggregated) historian read — OPC UA HistoryReadProcessed service. The
+///     aggregate column is a string (e.g. "Average", "Minimum") mapped by the Proxy from the
+///     OPC UA HistoryAggregateType enum so Galaxy.Host stays OPC-UA-free.
+/// </summary>
+[MessagePackObject]
+public sealed class HistoryReadProcessedRequest
+{
+    [Key(0)] public long SessionId { get; set; }
+    [Key(1)] public string TagReference { get; set; } = string.Empty;
+    [Key(2)] public long StartUtcUnixMs { get; set; }
+    [Key(3)] public long EndUtcUnixMs { get; set; }
+    [Key(4)] public long IntervalMs { get; set; }
+    [Key(5)] public string AggregateColumn { get; set; } = "Average";
+}
+
+[MessagePackObject]
+public sealed class HistoryReadProcessedResponse
+{
+    [Key(0)] public bool Success { get; set; }
+    [Key(1)] public string? Error { get; set; }
+    [Key(2)] public GalaxyDataValue[] Values { get; set; } = System.Array.Empty<GalaxyDataValue>();
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests/HistoryReadProcessedTests.cs

@@ -0,0 +1,158 @@
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using MessagePack;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Backend;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Backend.Galaxy;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Backend.Historian;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Backend.MxAccess;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Sta;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Shared.Contracts;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests;
+
+[Trait("Category", "Unit")]
+public sealed class HistoryReadProcessedTests
+{
+    [Fact]
+    public async Task ReturnsDisabledError_When_NoHistorianConfigured()
+    {
+        using var pump = new StaPump("Test.Sta");
+        await pump.WaitForStartedAsync();
+        var mx = new MxAccessClient(pump, new MxProxyAdapter(), "processed-test");
+        using var backend = new MxAccessGalaxyBackend(
+            new GalaxyRepository(new GalaxyRepositoryOptions { ConnectionString = "Server=.;Database=ZB;Integrated Security=True;" }),
+            mx,
+            historian: null);
+
+        var resp = await backend.HistoryReadProcessedAsync(new HistoryReadProcessedRequest
+        {
+            TagReference = "T",
+            StartUtcUnixMs = 0,
+            EndUtcUnixMs = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds(),
+            IntervalMs = 1000,
+            AggregateColumn = "Average",
+        }, CancellationToken.None);
+
+        resp.Success.ShouldBeFalse();
+        resp.Error.ShouldContain("Historian disabled");
+    }
+
+    [Fact]
+    public async Task Rejects_NonPositiveInterval()
+    {
+        using var pump = new StaPump("Test.Sta");
+        await pump.WaitForStartedAsync();
+        var mx = new MxAccessClient(pump, new MxProxyAdapter(), "processed-test");
+        var fake = new FakeHistorianDataSource();
+        using var backend = new MxAccessGalaxyBackend(
+            new GalaxyRepository(new GalaxyRepositoryOptions { ConnectionString = "Server=.;Database=ZB;Integrated Security=True;" }),
+            mx,
+            fake);
+
+        var resp = await backend.HistoryReadProcessedAsync(new HistoryReadProcessedRequest
+        {
+            TagReference = "T",
+            IntervalMs = 0,
+            AggregateColumn = "Average",
+        }, CancellationToken.None);
+
+        resp.Success.ShouldBeFalse();
+        resp.Error.ShouldContain("IntervalMs");
+    }
+
+    [Fact]
+    public async Task Maps_AggregateSample_With_Value_To_Good()
+    {
+        using var pump = new StaPump("Test.Sta");
+        await pump.WaitForStartedAsync();
+        var mx = new MxAccessClient(pump, new MxProxyAdapter(), "processed-test");
+        var fake = new FakeHistorianDataSource(new HistorianAggregateSample
+        {
+            Value = 12.34,
+            TimestampUtc = new DateTime(2026, 4, 18, 10, 0, 0, DateTimeKind.Utc),
+        });
+        using var backend = new MxAccessGalaxyBackend(
+            new GalaxyRepository(new GalaxyRepositoryOptions { ConnectionString = "Server=.;Database=ZB;Integrated Security=True;" }),
+            mx,
+            fake);
+
+        var resp = await backend.HistoryReadProcessedAsync(new HistoryReadProcessedRequest
+        {
+            TagReference = "T",
+            StartUtcUnixMs = 0,
+            EndUtcUnixMs = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds(),
+            IntervalMs = 60_000,
+            AggregateColumn = "Average",
+        }, CancellationToken.None);
+
+        resp.Success.ShouldBeTrue();
+        resp.Values.Length.ShouldBe(1);
+        resp.Values[0].StatusCode.ShouldBe(0u); // Good
+        resp.Values[0].ValueBytes.ShouldNotBeNull();
+        MessagePackSerializer.Deserialize<double>(resp.Values[0].ValueBytes!).ShouldBe(12.34);
+        fake.LastAggregateColumn.ShouldBe("Average");
+        fake.LastIntervalMs.ShouldBe(60_000d);
+    }
+
+    [Fact]
+    public async Task Maps_Null_Bucket_To_BadNoData()
+    {
+        using var pump = new StaPump("Test.Sta");
+        await pump.WaitForStartedAsync();
+        var mx = new MxAccessClient(pump, new MxProxyAdapter(), "processed-test");
+        var fake = new FakeHistorianDataSource(new HistorianAggregateSample
+        {
+            Value = null,
+            TimestampUtc = DateTime.UtcNow,
+        });
+        using var backend = new MxAccessGalaxyBackend(
+            new GalaxyRepository(new GalaxyRepositoryOptions { ConnectionString = "Server=.;Database=ZB;Integrated Security=True;" }),
+            mx,
+            fake);
+
+        var resp = await backend.HistoryReadProcessedAsync(new HistoryReadProcessedRequest
+        {
+            TagReference = "T",
+            IntervalMs = 1000,
+            AggregateColumn = "Minimum",
+        }, CancellationToken.None);
+
+        resp.Success.ShouldBeTrue();
+        resp.Values.Length.ShouldBe(1);
+        resp.Values[0].StatusCode.ShouldBe(0x800E0000u); // BadNoData
+        resp.Values[0].ValueBytes.ShouldBeNull();
+    }
+
+    private sealed class FakeHistorianDataSource : IHistorianDataSource
+    {
+        private readonly HistorianAggregateSample[] _samples;
+        public string? LastAggregateColumn { get; private set; }
+        public double LastIntervalMs { get; private set; }
+
+        public FakeHistorianDataSource(params HistorianAggregateSample[] samples) => _samples = samples;
+
+        public Task<List<HistorianSample>> ReadRawAsync(string tag, DateTime s, DateTime e, int max, CancellationToken ct)
+            => Task.FromResult(new List<HistorianSample>());
+
+        public Task<List<HistorianAggregateSample>> ReadAggregateAsync(
+            string tag, DateTime s, DateTime e, double intervalMs, string col, CancellationToken ct)
+        {
+            LastAggregateColumn = col;
+            LastIntervalMs = intervalMs;
+            return Task.FromResult(new List<HistorianAggregateSample>(_samples));
+        }
+
+        public Task<List<HistorianSample>> ReadAtTimeAsync(string tag, DateTime[] ts, CancellationToken ct)
+            => Task.FromResult(new List<HistorianSample>());
+
+        public Task<List<HistorianEventDto>> ReadEventsAsync(string? src, DateTime s, DateTime e, int max, CancellationToken ct)
+            => Task.FromResult(new List<HistorianEventDto>());
+
+        public HistorianHealthSnapshot GetHealthSnapshot() => new();
+        public void Dispose() { }
+    }
+}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests/HostStatusPushTests.cs

@@ -1,91 +0,0 @@
-using System;
-using System.Collections.Concurrent;
-using System.Threading;
-using System.Threading.Tasks;
-using ArchestrA.MxAccess;
-using Shouldly;
-using Xunit;
-using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Backend;
-using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Backend.Galaxy;
-using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Backend.MxAccess;
-using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Sta;
-using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Shared.Contracts;
-
-namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests;
-
-[Trait("Category", "Unit")]
-public sealed class HostStatusPushTests
-{
-    /// <summary>
-    ///     PR 8 — when MxAccessClient.ConnectionStateChanged fires false→true→false,
-    ///     MxAccessGalaxyBackend raises OnHostStatusChanged once per transition with
-    ///     HostName=ClientName, RuntimeStatus="Running"/"Stopped", and a timestamp.
-    ///     This is the gateway-level signal; per-platform ScanState probes are deferred.
-    /// </summary>
-    [Fact]
-    public async Task ConnectionStateChanged_raises_OnHostStatusChanged_with_gateway_name()
-    {
-        using var pump = new StaPump("Test.Sta");
-        await pump.WaitForStartedAsync();
-        var proxy = new FakeProxy();
-        var mx = new MxAccessClient(pump, proxy, "GatewayClient", new MxAccessClientOptions { AutoReconnect = false });
-        using var backend = new MxAccessGalaxyBackend(
-            new GalaxyRepository(new GalaxyRepositoryOptions { ConnectionString = "Server=.;Database=ZB;Integrated Security=True;" }),
-            mx,
-            historian: null);
-
-        var notifications = new ConcurrentQueue<HostConnectivityStatus>();
-        backend.OnHostStatusChanged += (_, s) => notifications.Enqueue(s);
-
-        await mx.ConnectAsync();
-        await mx.DisconnectAsync();
-
-        notifications.Count.ShouldBe(2);
-        notifications.TryDequeue(out var first).ShouldBeTrue();
-        first!.HostName.ShouldBe("GatewayClient");
-        first.RuntimeStatus.ShouldBe("Running");
-        first.LastObservedUtcUnixMs.ShouldBeGreaterThan(0);
-
-        notifications.TryDequeue(out var second).ShouldBeTrue();
-        second!.HostName.ShouldBe("GatewayClient");
-        second.RuntimeStatus.ShouldBe("Stopped");
-    }
-
-    [Fact]
-    public async Task Dispose_unsubscribes_so_post_dispose_state_changes_do_not_fire_events()
-    {
-        using var pump = new StaPump("Test.Sta");
-        await pump.WaitForStartedAsync();
-        var proxy = new FakeProxy();
-        var mx = new MxAccessClient(pump, proxy, "GatewayClient", new MxAccessClientOptions { AutoReconnect = false });
-        var backend = new MxAccessGalaxyBackend(
-            new GalaxyRepository(new GalaxyRepositoryOptions { ConnectionString = "Server=.;Database=ZB;Integrated Security=True;" }),
-            mx,
-            historian: null);
-
-        var count = 0;
-        backend.OnHostStatusChanged += (_, _) => Interlocked.Increment(ref count);
-
-        await mx.ConnectAsync();
-        count.ShouldBe(1);
-
-        backend.Dispose();
-        await mx.DisconnectAsync();
-
-        count.ShouldBe(1); // no second notification after Dispose
-    }
-
-    private sealed class FakeProxy : IMxProxy
-    {
-        private int _next = 1;
-        public int Register(string _) => 42;
-        public void Unregister(int _) { }
-        public int AddItem(int _, string __) => Interlocked.Increment(ref _next);
-        public void RemoveItem(int _, int __) { }
-        public void AdviseSupervisory(int _, int __) { }
-        public void UnAdviseSupervisory(int _, int __) { }
-        public void Write(int _, int __, object ___, int ____) { }
-        public event MxDataChangeHandler? OnDataChange { add { } remove { } }
-        public event MxWriteCompleteHandler? OnWriteComplete { add { } remove { } }
-    }
-}

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Tests.csproj

@@ -24,11 +24,6 @@
     <ItemGroup>
         <ProjectReference Include="..\..\src\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host\ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.csproj"/>
         <Reference Include="System.ServiceProcess"/>
-        <!-- IMxProxy's delegate signatures mention ArchestrA.MxAccess.MXSTATUS_PROXY, so tests
-             implementing the interface must resolve that type at compile time. -->
-        <Reference Include="ArchestrA.MxAccess">
-            <HintPath>..\..\lib\ArchestrA.MxAccess.dll</HintPath>
-        </Reference>
     </ItemGroup>
 
     <ItemGroup>

tests/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests/AggregateColumnMappingTests.cs

@@ -0,0 +1,27 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Proxy.Tests;
+
+[Trait("Category", "Unit")]
+public sealed class AggregateColumnMappingTests
+{
+    [Theory]
+    [InlineData(HistoryAggregateType.Average, "Average")]
+    [InlineData(HistoryAggregateType.Minimum, "Minimum")]
+    [InlineData(HistoryAggregateType.Maximum, "Maximum")]
+    [InlineData(HistoryAggregateType.Count, "ValueCount")]
+    public void Maps_OpcUa_enum_to_AnalogSummary_column(HistoryAggregateType aggregate, string expected)
+    {
+        GalaxyProxyDriver.MapAggregateToColumn(aggregate).ShouldBe(expected);
+    }
+
+    [Fact]
+    public void Total_is_not_supported()
+    {
+        Should.Throw<System.NotSupportedException>(
+            () => GalaxyProxyDriver.MapAggregateToColumn(HistoryAggregateType.Total));
+    }
+}