P0: real SV phasor angles, nominal 4I+4V presentation and honest sync diagnostics

src/ProcessBus.App.Wpf/Controls/PhasorDiagramControl.cs

@@ -73,10 +73,12 @@
     {
         var width = double.IsInfinity(availableSize.Width) ? 360 : availableSize.Width;
         var height = double.IsInfinity(availableSize.Height) ? 360 : availableSize.Height;
-        return new Size(Math.Max(280, width), Math.Max(280, height));
+        // Do not impose 280px into a 210px high WPF row: the previous desired
+        // size overflowed its clip and cut off vectors / phase labels.
+        return new Size(Math.Max(120, width), Math.Max(140, height));
     }
 
     protected override void OnRender(DrawingContext dc)
     {
         base.OnRender(dc);
 
@@ -121,7 +123,7 @@
         DrawSoftOriginGlow(dc, center);
 
         foreach (var item in validItems)
-            DrawPhasor(dc, center, radius, item, voltageMax, currentMax);
+            DrawPhasor(dc, bounds, center, radius, item, voltageMax, currentMax);
 
     }
 
@@ -159,7 +161,7 @@
         dc.DrawEllipse(OriginBrush, null, center, 4.0, 4.0);
     }
 
-    private static void DrawPhasor(DrawingContext dc, Point center, double radius, PhasorDisplayItem item, double voltageMax, double currentMax)
+    private static void DrawPhasor(DrawingContext dc, Rect bounds, Point center, double radius, PhasorDisplayItem item, double voltageMax, double currentMax)
     {
         var maxMagnitude = item.Family == PhasorFamily.Voltage ? voltageMax : currentMax;
         if (maxMagnitude <= 0)
@@ -192,7 +194,7 @@
         dc.DrawLine(pen, center, end);
 
         DrawArrowHead(dc, center, end, brush, item.Family == PhasorFamily.Voltage ? 17.0 : 15.0);
-        DrawVectorLabel(dc, item, center, end, brush);
+        DrawVectorLabel(dc, bounds, item, center, end, brush);
     }
 
     private static void DrawArrowHead(DrawingContext dc, Point start, Point end, Brush brush, double arrowLength)
@@ -219,7 +221,7 @@
         dc.DrawGeometry(brush, null, geometry);
     }
 
-    private static void DrawVectorLabel(DrawingContext dc, PhasorDisplayItem item, Point center, Point end, Brush brush)
+    private static void DrawVectorLabel(DrawingContext dc, Rect bounds, PhasorDisplayItem item, Point center, Point end, Brush brush)
     {
         var direction = end - center;
         if (direction.Length <= 0.001)
@@ -240,7 +242,10 @@
         else
             labelPoint.Y -= 17;
 
-        DrawText(dc, label, 13, labelPoint, brush, LabelTypeface);
+        var text = CreateText(label, 11.5, brush, LabelTypeface);
+        labelPoint.X = Math.Clamp(labelPoint.X, bounds.Left + 4, Math.Max(bounds.Left + 4, bounds.Right - text.Width - 4));
+        labelPoint.Y = Math.Clamp(labelPoint.Y, bounds.Top + 4, Math.Max(bounds.Top + 4, bounds.Bottom - text.Height - 4));
+        dc.DrawText(text, labelPoint);
     }
 
     private static void DrawCenteredMessage(DrawingContext dc, Point center, string text)
@@ -311,7 +316,7 @@
             VisualTreeHelper.GetDpi(Application.Current.MainWindow).PixelsPerDip);
     }
 
     private static Brush CreateBrush(string hex)
     {
         var brush = (SolidColorBrush)new BrushConverter().ConvertFromString(hex)!;
         brush.Freeze();

src/ProcessBus.App.Wpf/MainWindow.xaml

@@ -2564,7 +2564,7 @@
                                             CornerRadius="9" Padding="12,10"
                                             ToolTip="{Binding Diagnostics.ValidityText}">
                                         <StackPanel>
-                                            <TextBlock Text="SV QUALITY / SYNC" Foreground="#9BC7E4" FontSize="10.5"
+                                            <TextBlock Text="SV QUALITY" Foreground="#9BC7E4" FontSize="10.5"
                                                        FontWeight="SemiBold"/>
                                             <TextBlock Text="{Binding Diagnostics.SvQualityHeadlineText}"
                                                        FontSize="20" FontWeight="SemiBold"
@@ -2586,6 +2586,25 @@
                                             <TextBlock Text="{Binding Diagnostics.SvQualityEvidenceText}"
                                                        Foreground="#B9D1E5" FontSize="11"
                                                        TextWrapping="Wrap" ToolTip="{Binding Diagnostics.ValidityText}"/>
+                                            <DockPanel Margin="0,6,0,0" LastChildFill="False">
+                                                <TextBlock Text="SAMPLE SYNC" FontSize="10" Foreground="#9BC7E4"
+                                                           VerticalAlignment="Center" Margin="0,0,8,0"/>
+                                                <TextBlock Text="{Binding Diagnostics.SvSampleSyncHeadlineText}"
+                                                           FontSize="11.5" FontWeight="SemiBold">
+                                                    <TextBlock.Style>
+                                                        <Style TargetType="TextBlock">
+                                                            <Setter Property="Foreground" Value="#F3C76D"/>
+                                                            <Style.Triggers>
+                                                                <DataTrigger Binding="{Binding Diagnostics.SmpSynchText}" Value="0">
+                                                                    <Setter Property="Foreground" Value="#FF8484"/>
+                                                                </DataTrigger>
+                                                            </Style.Triggers>
+                                                        </Style>
+                                                    </TextBlock.Style>
+                                                </TextBlock>
+                                            </DockPanel>
+                                            <TextBlock Text="{Binding Diagnostics.SvSampleSyncEvidenceText}"
+                                                       FontSize="10" Foreground="#A8C5DD" TextTrimming="CharacterEllipsis"/>
                                         </StackPanel>
                                     </Border>
                                 </UniformGrid>

src/ProcessBus.App.Wpf/ViewModels/MainWindowViewModel.cs

@@ -878,25 +878,43 @@
     public IReadOnlyList<string> WaveformTimebaseOptions { get; } = ["1 cycle", "2 cycles", "4 cycles", "8 cycles"];
     public IReadOnlyList<string> WaveformModeOptions { get; } = ["Locked"];
     public IReadOnlyList<string> WaveformMarkerOptions { get; } = ["On", "Off"];
-    public IReadOnlyList<string> EngineeringScaleOptions { get; } = [RawScaleText, NominalScaleText];
+    public IReadOnlyList<string> EngineeringScaleOptions { get; } = [NominalScaleText, RawScaleText];
+
+    private SvEngineeringScale ResolveSelectedStreamScale(string streamId)
+    {
+        if (_explicitSvScales.TryGetValue(streamId, out var explicitMode))
+            return explicitMode;
+
+        // Use the decoder's recognized 4I+4V instMag/q layout, not an APPID or
+        // publisher name, as eligibility for an ASSUMED nominal display.
+        var details = SelectedStreamDetails;
+        return SelectedStream is not null &&
+               string.Equals(SelectedStream.StreamId, streamId, StringComparison.OrdinalIgnoreCase) &&
+               details is not null &&
+               string.Equals(details.SvId, SelectedStream.SvId, StringComparison.OrdinalIgnoreCase) &&
+               SvEngineeringScaleFactors.IsRecognizedNominalCandidate(details.SampleValueMappingText)
+            ? SvEngineeringScale.Nominal4I4V
+            : SvEngineeringScale.RawCounts;
+    }
+
     public string SelectedEngineeringScale
     {
         get => SelectedStream is not null &&
-            _explicitSvScales.TryGetValue(SelectedStream.StreamId, out var mode) &&
-            mode == SvEngineeringScale.Nominal4I4V ? NominalScaleText : RawScaleText;
+               ResolveSelectedStreamScale(SelectedStream.StreamId) == SvEngineeringScale.Nominal4I4V
+            ? NominalScaleText : RawScaleText;
         set
         {
             if (SelectedStream is null || (value != RawScaleText && value != NominalScaleText))
                 return;
             var next = value == NominalScaleText ? SvEngineeringScale.Nominal4I4V : SvEngineeringScale.RawCounts;
             var key = SelectedStream.StreamId;
-            if (_explicitSvScales.TryGetValue(key, out var previous) ? previous == next : next == SvEngineeringScale.RawCounts)
+            if (ResolveSelectedStreamScale(key) == next)
                 return;
 
-            if (next == SvEngineeringScale.RawCounts) _explicitSvScales.Remove(key);
-            else _explicitSvScales[key] = next;
+            // Store raw overrides too: selecting raw must not auto-revert to
+            // nominal on the next 500ms stream refresh.
+            _explicitSvScales[key] = next;
             ApplySelectedStreamScale(key);
-            // No stale physical metering, vectors, waveform, or wrong-stream cached state.
             _streamWorkspaces.Remove(key);
             RestoreSelectedStreamWorkspace(SelectedStream);
             OnPropertyChanged();
@@ -909,15 +927,13 @@
     public string EngineeringScaleExplanation => SelectedStream is null
         ? "Select an SV stream to see its measurement units."
         : SelectedEngineeringScale == NominalScaleText
-            ? "Operator-selected 4I+4V nominal scaling; not calibrated or independently verified. Applies to this stream only."
-            : "Uncalibrated raw counts: waveform/angles remain available; physical power is unavailable.";
+            ? "Assumed 4I+4V nominal: 1 mA / 10 mV per count. Display estimate only; not calibrated or SCL-verified. Choose Raw counts anytime."
+            : "Raw SV counts: no electrical units inferred. Use nominal 4I+4V only when its layout is confirmed.";
 
     private void ApplySelectedStreamScale(string? streamId)
     {
         if (string.IsNullOrWhiteSpace(streamId)) return;
-        var mode = _explicitSvScales.TryGetValue(streamId, out var selected)
-            ? selected : SvEngineeringScale.RawCounts;
-        _rawDataSource.SetSvEngineeringScale(streamId, mode);
+        _rawDataSource.SetSvEngineeringScale(streamId, ResolveSelectedStreamScale(streamId));
     }
 
     public IReadOnlyList<string> WaveformVoltageScaleOptions { get; } =
@@ -1540,6 +1556,7 @@
 
     // ===== HEALTH =====
     private bool HasDiagnosticWarning =>
+        Diagnostics.SmpSynchText == "0" ||
         Diagnostics.DecodeErrors > 0 ||
         Diagnostics.CaptureDriverDroppedFrames > 0 ||
         Diagnostics.SequenceErrors > 0 ||
@@ -1884,6 +1901,8 @@
     private string BuildHealthWarningText()
     {
         var parts = new List<string>(5);
+        if (Diagnostics.SmpSynchText == "0")
+            parts.Add("SV samples report NOT SYNCED (smpSynch=0)");
         if (Diagnostics.DecodeErrors > 0)
             parts.Add($"decode rejects {Diagnostics.DecodeErrors}");
         if (Diagnostics.SequenceErrors > 0)
@@ -2226,6 +2245,11 @@
     private void UpdateSelectedStreamWorkspaceFromSnapshot(string? selectedStreamId, AnalogValuesSnapshot analogValues, WaveformSnapshot waveform)
     {
         _displayedSelectedStreamDetails = _state.SelectedStreamDetails;
+        // Refresh auto-nominal eligibility after the decoder has discovered a
+        // recognized mapping; next coherent snapshot uses the chosen units.
+        ApplySelectedStreamScale(selectedStreamId);
+        OnPropertyChanged(nameof(SelectedEngineeringScale));
+        OnPropertyChanged(nameof(EngineeringScaleExplanation));
 
         // ARSVIN-style display contract: phasor vectors are derived from the latest
         // engineering snapshot on every UI refresh. Do not use object-reference caching
@@ -4280,7 +4304,7 @@
             Name = name,
             Family = family,
             Magnitude = channel.RmsValue,
-            AngleDegrees = forceAngleZero && channel.RmsValue.HasValue ? 0.0 : channel.AngleDegrees,
+            AngleDegrees = forceAngleZero && channel.AngleDegrees.HasValue ? 0.0 : channel.AngleDegrees,
             Unit = channel.Unit
         };
     }
@@ -4562,7 +4586,7 @@
     public double? DeltaMs { get; init; }
     public string SemanticChangedSummaryText { get; init; } = string.Empty;
 
     public string TimeText => Source.LastSeenUtc.ToString("HH:mm:ss.fff");
     public string DeltaText => DeltaMs.HasValue ? $"{DeltaMs.Value:0.0}" : "-";
 
     public string GoId => Source.GoId;
@@ -4747,7 +4771,7 @@
             var age = DateTime.UtcNow - LastSeenUtc.Value;
             return age.TotalSeconds < 60
                 ? $"last {age.TotalSeconds:0.0}s"
                 : LastSeenUtc.Value.ToLocalTime().ToString("HH:mm:ss");
         }
     }
 
@@ -4828,7 +4852,7 @@
     public string EntryCountText => $"{Entries.Count} entry(s)";
     public string SummaryText => $"{IedName}  -  {TransportText}";
     public string ExpectedKey => $"{Protocol}|{SourceFileName}|{IedName}|{ControlBlockReference}|{DisplayName}";
     public string ExpectedConfRevText => ConfRev > 0 ? ConfRev.ToString() : "N/A";
 
     public static SclStreamCatalogRow FromSv(string sourceFileName, SclSvStreamModel stream, string liveStatus)
         => new()
@@ -5057,7 +5081,7 @@
             return ("No evidence captured yet", string.Empty);
 
         var parts = evidence
             .Split(new[] { "; " }, StringSplitOptions.RemoveEmptyEntries)
             .Select(part => part.Trim())
             .Where(part => part.Length > 0)
             .ToArray();

src/ProcessBus.Core/Models/SvDiagnosticsSnapshot.cs

@@ -73,7 +73,7 @@ public sealed class SvDiagnosticsSnapshot
         : "N/A";
 
     public string SvJitterStatisticsText =>
-        $"Mean |Δ| {FormatMicroseconds(AverageAbsJitterMicroseconds)} · Max |Δ| {FormatMicroseconds(MaxAbsJitterMicroseconds)}";
+        $"Mean |Δ| {FormatMicroseconds(AverageAbsJitterMicroseconds)} · Max |Δ| {FormatMicroseconds(MaxAbsJitterMicroseconds)} (last 4000 intervals)";
 
     public string SvJitterExcursionsText =>
         $"≥300 µs: {RecentJitterOver300MicrosecondsCount} / 5s · {JitterOver300MicrosecondsCount} total";
@@ -96,8 +96,18 @@ public sealed class SvDiagnosticsSnapshot
         _ => "UNVERIFIED"
     };
 
-    public string SvQualityEvidenceText => $"{ValidityText} · smpSynch: {SmpSynchText}" +
-        (SmpSynchText == "N/A" ? " (unavailable)" : " (observed)");
+    public string SvQualityEvidenceText => ValidityText;
+
+    // The source claims synchronization through smpSynch; observed PTP traffic
+    // is not independent proof that the publisher's sampling clock is locked.
+    public string SvSampleSyncHeadlineText => SmpSynchText switch
+    {
+        "0" => "NOT SYNCED",
+        "1" => "LOCAL REF REPORTED",
+        "2" => "GLOBAL REF REPORTED",
+        _ => "UNVERIFIED"
+    };
+    public string SvSampleSyncEvidenceText => $"smpSynch={SmpSynchText} · publisher flag only";
     public string SvArrivalIntervalText =>
         $"Actual Δ {FormatMicroseconds(CurrentDeltaMicroseconds)} · Expected Δ {FormatMicroseconds(ExpectedDeltaMicroseconds)}";
     public string SvArrivalAuthorityText =>

src/ProcessBus.Core/Models/SvEngineeringScale.cs

@@ -25,6 +25,14 @@ public static string Unit(SvEngineeringScale mode, string channel)
             ? "counts"
             : channel.StartsWith("U", StringComparison.OrdinalIgnoreCase) ? "V" : "A";
 
+    // Offer engineering-friendly nominal units only when the receive decoder
+    // has identified the exact 16-entry 4I+4V instMag/q layout. This is an
+    // ASSUMED profile, not SCL-certified calibration or universal SV scaling.
+    // Never use svID, APPID or raw frame length alone for scale authority.
+    public static bool IsRecognizedNominalCandidate(string? mappingText) =>
+        !string.IsNullOrWhiteSpace(mappingText) &&
+        mappingText.Contains("raw 4I4V instMag/q", StringComparison.OrdinalIgnoreCase);
+
     public static bool IsPhysical(SvEngineeringScale mode)
         => mode == SvEngineeringScale.Nominal4I4V;
 }

src/ProcessBus.Iec61850.Raw/Analysis/RawProcessBusAnalyzer.cs

@@ -308,7 +308,7 @@
             return null;
 
         var appId = FormatAppId(frame.AppId);
         var vlanId = frame.Ethernet.Vlan?.VlanId.ToString() ?? "Untagged";
         var confRev = asdu.ConfRev?.ToString() ?? "N/A";
 
         return _svChannelMappings
@@ -1421,8 +1421,14 @@
             // not freeze the vector display. The old display-hold path kept returning the
             // previous angle after transient sequence warnings, so the phasor diagram only
             // appeared to refresh after a user clicked SV Explorer and rebuilt the workspace.
-            if (!rawAngle.HasValue || reference is null)
-                return _displayAngles[channel] ?? DefaultAngleDegrees(channel);
+            // Never synthesize a nominal phase angle or replay a previous channel
+            // angle when this coherent SV window lacks valid phasor evidence.
+            // In particular an absent Ic must not produce a convincing +90° arrow.
+            if (!rawAngle.HasValue || !double.IsFinite(rawAngle.Value) || reference is null)
+            {
+                _displayAngles[channel] = null;
+                return null;
+            }
 
             var referenceValue = reference.Value;
             var relativeAngle = string.Equals(channel, referenceValue.Channel, StringComparison.OrdinalIgnoreCase)
@@ -1680,21 +1686,33 @@
 
         private static double? GetFundamentalAngleDegrees(IReadOnlyList<ScopeSampleFrame> frames, string channel, int samplesPerCycle)
         {
-            var values = GetChannelSamples(frames, channel);
-            if (samplesPerCycle <= 1 || values.Count < samplesPerCycle)
+            if (samplesPerCycle <= 1 || frames.Count < samplesPerCycle)
                 return null;
 
+            // Keep every channel on the SAME acquisition slot index. Filtering out
+            // absent channel values and reindexing them shifts its electrical phase
+            // relative to Ua without changing the displayed waveform's slot positions.
             var sine = 0.0;
             var cosine = 0.0;
+            var sumSquares = 0.0;
             var phaseStep = 2.0 * Math.PI / samplesPerCycle;
-            for (var index = 0; index < values.Count; index++)
+            for (var index = 0; index < frames.Count; index++)
             {
+                var value = frames[index].GetValue(channel);
+                if (!value.HasValue || !double.IsFinite(value.Value))
+                    return null;
+
                 var angle = phaseStep * index;
-                sine += values[index] * Math.Sin(angle);
-                cosine += values[index] * Math.Cos(angle);
+                sine += value.Value * Math.Sin(angle);
+                cosine += value.Value * Math.Cos(angle);
+                sumSquares += value.Value * value.Value;
             }
 
-            if (Math.Abs(sine) < 1e-9 && Math.Abs(cosine) < 1e-9)
+            // An all-zero/vanishing fundamental has no mathematically meaningful angle.
+            // Refuse an invented vector rather than using a fixed R/S/T template.
+            var fundamentalMagnitude = Math.Sqrt(sine * sine + cosine * cosine);
+            if (sumSquares <= 0 ||
+                fundamentalMagnitude <= 1e-8 * Math.Sqrt(sumSquares * frames.Count))
                 return null;
 
             return NormalizeAngleDegrees(Math.Atan2(cosine, sine) * 180.0 / Math.PI);