diff --git a/IoListTestingWindow.PrintPreview.cs b/IoListTestingWindow.PrintPreview.cs
new file mode 100644
index 0000000..1db01c0
--- /dev/null
+++ b/IoListTestingWindow.PrintPreview.cs
@@ -0,0 +1,317 @@
+using System.ComponentModel;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+using System.Windows.Threading;
+using ArIED61850Tester.Services.IoTesting;
+using Microsoft.Win32;
+
+namespace ArIED61850Tester;
+
+public partial class IoListTestingWindow
+{
+    private bool _printPreviewInstalled;
+    private bool _printPreviewActive;
+    private DataGrid? _signalWorkspaceGrid;
+    private Grid? _printPreviewHost;
+    private WebBrowser? _printPreviewBrowser;
+    private Button? _printPreviewToggle;
+    private TextBlock? _printPreviewTitle;
+    private TextBlock? _printPreviewSubtitle;
+    private DispatcherTimer? _preparationStateGuard;
+
+    protected override void OnContentRendered(EventArgs e)
+    {
+        base.OnContentRendered(e);
+        if (_printPreviewInstalled)
+            return;
+
+        InstallPerIedPrintPreview();
+        InstallPreparationStateGuard();
+        PropertyChanged += PrintPreviewWindow_PropertyChanged;
+        Session.PropertyChanged += PrintPreviewSession_PropertyChanged;
+        Closed += PrintPreviewWindow_Closed;
+        _printPreviewInstalled = true;
+    }
+
+    private void InstallPerIedPrintPreview()
+    {
+        if (Content is not Grid root)
+            return;
+
+        var middle = root.Children
+            .OfType<Grid>()
+            .FirstOrDefault(child => Grid.GetRow(child) == 2);
+        var workspaceBorder = middle?.Children
+            .OfType<Border>()
+            .FirstOrDefault(child => Grid.GetColumn(child) == 2);
+        if (workspaceBorder?.Child is not Grid workspaceGrid)
+            return;
+
+        _signalWorkspaceGrid = workspaceGrid.Children.OfType<DataGrid>().FirstOrDefault();
+        if (_signalWorkspaceGrid == null)
+            return;
+
+        RemoveMainPreparationSurface(workspaceGrid);
+        InstallPreviewToggle(root);
+        _printPreviewHost = BuildPrintPreviewHost();
+        Grid.SetRow(_printPreviewHost, Grid.GetRow(_signalWorkspaceGrid));
+        workspaceGrid.Children.Add(_printPreviewHost);
+    }
+
+    private static void RemoveMainPreparationSurface(Grid workspaceGrid)
+    {
+        var preparationSurface = workspaceGrid.Children
+            .OfType<Border>()
+            .FirstOrDefault(border => Grid.GetRow(border) == 1 &&
+                border.Descendants<ProgressBar>().Any(progress => progress.IsIndeterminate));
+        if (preparationSurface != null)
+            workspaceGrid.Children.Remove(preparationSurface);
+
+        if (workspaceGrid.RowDefinitions.Count > 1)
+            workspaceGrid.RowDefinitions[1].Height = new GridLength(0);
+        if (workspaceGrid.RowDefinitions.Count > 2)
+            workspaceGrid.RowDefinitions[2].Height = new GridLength(10);
+    }
+
+    private void InstallPreviewToggle(Grid root)
+    {
+        var headerBorder = root.Children
+            .OfType<Border>()
+            .FirstOrDefault(child => Grid.GetRow(child) == 0);
+        var headerGrid = headerBorder?.Child as Grid;
+        var actions = headerGrid?.Children.OfType<WrapPanel>().FirstOrDefault();
+        if (actions == null)
+            return;
+
+        _printPreviewToggle = BuildButton("Print Preview", TogglePrintPreview_Click, primary: false);
+        _printPreviewToggle.ToolTip = "Preview the selected IED report in the workspace";
+        var pdfButtonIndex = actions.Children
+            .OfType<Button>()
+            .Select((button, index) => new { button, index })
+            .FirstOrDefault(item => string.Equals(item.button.Content?.ToString(), "PDF", StringComparison.Ordinal))?.index;
+        actions.Children.Insert(pdfButtonIndex.HasValue ? pdfButtonIndex.Value + 1 : actions.Children.Count, _printPreviewToggle);
+    }
+
+    private Grid BuildPrintPreviewHost()
+    {
+        var host = new Grid
+        {
+            Visibility = Visibility.Collapsed,
+            Background = Brushes.White
+        };
+        host.RowDefinitions.Add(new RowDefinition { Height = GridLength.Auto });
+        host.RowDefinitions.Add(new RowDefinition { Height = new GridLength(10) });
+        host.RowDefinitions.Add(new RowDefinition { Height = new GridLength(1, GridUnitType.Star) });
+
+        var commandBar = new Border
+        {
+            Background = new SolidColorBrush(Color.FromRgb(248, 250, 253)),
+            BorderBrush = new SolidColorBrush(Color.FromRgb(222, 230, 240)),
+            BorderThickness = new Thickness(1),
+            CornerRadius = new CornerRadius(12),
+            Padding = new Thickness(13, 10, 13, 10)
+        };
+        var commandGrid = new Grid();
+        commandGrid.ColumnDefinitions.Add(new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) });
+        commandGrid.ColumnDefinitions.Add(new ColumnDefinition { Width = GridLength.Auto });
+
+        var text = new StackPanel();
+        _printPreviewTitle = new TextBlock
+        {
+            Text = "Print Preview",
+            FontSize = 15.5,
+            FontWeight = FontWeights.SemiBold,
+            Foreground = (Brush?)TryFindResource("Ink") ?? Brushes.Black
+        };
+        _printPreviewSubtitle = new TextBlock
+        {
+            Margin = new Thickness(0, 4, 0, 0),
+            FontSize = 10.8,
+            Foreground = (Brush?)TryFindResource("Muted") ?? Brushes.DimGray
+        };
+        text.Children.Add(_printPreviewTitle);
+        text.Children.Add(_printPreviewSubtitle);
+        commandGrid.Children.Add(text);
+
+        var commands = new StackPanel
+        {
+            Orientation = Orientation.Horizontal,
+            HorizontalAlignment = HorizontalAlignment.Right,
+            VerticalAlignment = VerticalAlignment.Center
+        };
+        commands.Children.Add(BuildButton("Refresh", (_, _) => RefreshPrintPreview(), primary: false));
+        commands.Children.Add(BuildButton("Print", PrintCurrentPreview_Click, primary: false));
+        commands.Children.Add(BuildButton("Export IED PDF", ExportSelectedIedPdf_Click, primary: true));
+        commands.Children.Add(BuildButton("Signals", TogglePrintPreview_Click, primary: false));
+        Grid.SetColumn(commands, 1);
+        commandGrid.Children.Add(commands);
+        commandBar.Child = commandGrid;
+        host.Children.Add(commandBar);
+
+        var browserFrame = new Border
+        {
+            Background = Brushes.White,
+            BorderBrush = new SolidColorBrush(Color.FromRgb(222, 230, 240)),
+            BorderThickness = new Thickness(1),
+            CornerRadius = new CornerRadius(12),
+            ClipToBounds = true
+        };
+        _printPreviewBrowser = new WebBrowser();
+        browserFrame.Child = _printPreviewBrowser;
+        Grid.SetRow(browserFrame, 2);
+        host.Children.Add(browserFrame);
+        return host;
+    }
+
+    private Button BuildButton(string text, RoutedEventHandler click, bool primary)
+    {
+        var button = new Button
+        {
+            Content = text,
+            Style = TryFindResource(primary ? "PrimaryButton" : "SoftButton") as Style,
+            Padding = new Thickness(11, 7, 11, 7),
+            Margin = new Thickness(0, 0, 6, 0),
+            VerticalAlignment = VerticalAlignment.Center
+        };
+        button.Click += click;
+        return button;
+    }
+
+    private void TogglePrintPreview_Click(object sender, RoutedEventArgs e)
+    {
+        if (_signalWorkspaceGrid == null || _printPreviewHost == null)
+            return;
+
+        _printPreviewActive = !_printPreviewActive;
+        _signalWorkspaceGrid.Visibility = _printPreviewActive ? Visibility.Collapsed : Visibility.Visible;
+        _printPreviewHost.Visibility = _printPreviewActive ? Visibility.Visible : Visibility.Collapsed;
+        if (_printPreviewToggle != null)
+            _printPreviewToggle.Content = _printPreviewActive ? "Signals" : "Print Preview";
+        if (_printPreviewActive)
+            RefreshPrintPreview();
+    }
+
+    private void RefreshPrintPreview()
+    {
+        if (!_printPreviewActive || _printPreviewBrowser == null || SelectedIed == null)
+            return;
+
+        _printPreviewTitle!.Text = $"Print Preview · {SelectedIed.IedName}";
+        _printPreviewSubtitle!.Text = $"{SelectedIed.IpAddress} · per-IED evidence · {(Session.IsSessionActive ? "live draft" : "sealed/current state")}";
+        var html = IoFatReportPreviewService.BuildHtml(
+            Project,
+            SelectedIed,
+            Session.IsSessionActive && ReferenceEquals(Session.ActiveIed, SelectedIed));
+        _printPreviewBrowser.NavigateToString(html);
+    }
+
+    private void PrintCurrentPreview_Click(object sender, RoutedEventArgs e)
+    {
+        if (_printPreviewBrowser == null)
+            return;
+        try
+        {
+            _printPreviewBrowser.InvokeScript("print");
+        }
+        catch (Exception ex)
+        {
+            MessageBox.Show(this, ex.Message, "Print preview", MessageBoxButton.OK, MessageBoxImage.Warning);
+        }
+    }
+
+    private void ExportSelectedIedPdf_Click(object sender, RoutedEventArgs e)
+    {
+        if (SelectedIed == null)
+            return;
+        if (!EnsureSessionSealedForExport($"{SelectedIed.IedName} PDF evidence report"))
+            return;
+
+        var dialog = new SaveFileDialog
+        {
+            Title = $"Export {SelectedIed.IedName} native ARSAS IO FAT PDF",
+            Filter = "PDF evidence report (*.pdf)|*.pdf",
+            FileName = $"{SafeFileName(Project.ProjectId)}_{SafeFileName(SelectedIed.IedName)}_IO-FAT_{DateTime.Now:yyyyMMdd_HHmm}.pdf",
+            AddExtension = true,
+            DefaultExt = ".pdf",
+            OverwritePrompt = true
+        };
+        if (dialog.ShowDialog(this) != true)
+            return;
+
+        try
+        {
+            Storage?.SaveNow();
+            var scopedProject = IoFatReportPreviewService.CreateIedScopedProject(Project, SelectedIed);
+            IoFatPdfReportService.Save(dialog.FileName, scopedProject);
+            MessageBox.Show(
+                this,
+                $"Per-IED PDF created successfully.\n\n{dialog.FileName}",
+                "IED PDF exported",
+                MessageBoxButton.OK,
+                MessageBoxImage.Information);
+        }
+        catch (Exception ex) when (ex is IOException or UnauthorizedAccessException or InvalidDataException or InvalidOperationException or ArgumentException)
+        {
+            MessageBox.Show(this, ex.Message, "IED PDF export failed", MessageBoxButton.OK, MessageBoxImage.Error);
+        }
+    }
+
+    private void InstallPreparationStateGuard()
+    {
+        _preparationStateGuard = new DispatcherTimer(DispatcherPriority.Background)
+        {
+            Interval = TimeSpan.FromMilliseconds(180)
+        };
+        _preparationStateGuard.Tick += (_, _) => ClearStalePreparationFlags();
+        _preparationStateGuard.Start();
+    }
+
+    private void ClearStalePreparationFlags()
+    {
+        foreach (var ied in Project.Ieds)
+        {
+            if (!ied.IsPreparing || ReferenceEquals(ied, _preparingIed))
+                continue;
+            ied.SetPreparationState(false, ied.LiveStatusText);
+        }
+    }
+
+    private void PrintPreviewWindow_PropertyChanged(object? sender, PropertyChangedEventArgs e)
+    {
+        if (_printPreviewActive && e.PropertyName == nameof(SelectedIed))
+            Dispatcher.BeginInvoke(DispatcherPriority.Background, RefreshPrintPreview);
+    }
+
+    private void PrintPreviewSession_PropertyChanged(object? sender, PropertyChangedEventArgs e)
+    {
+        if (_printPreviewActive && e.PropertyName is nameof(Session.State) or nameof(Session.EvidenceRecordCount))
+            Dispatcher.BeginInvoke(DispatcherPriority.Background, RefreshPrintPreview);
+    }
+
+    private void PrintPreviewWindow_Closed(object? sender, EventArgs e)
+    {
+        _preparationStateGuard?.Stop();
+        PropertyChanged -= PrintPreviewWindow_PropertyChanged;
+        Session.PropertyChanged -= PrintPreviewSession_PropertyChanged;
+        Closed -= PrintPreviewWindow_Closed;
+    }
+}
+
+internal static class IoFatVisualTreeExtensions
+{
+    public static IEnumerable<T> Descendants<T>(this DependencyObject parent) where T : DependencyObject
+    {
+        if (parent == null)
+            yield break;
+        var count = VisualTreeHelper.GetChildrenCount(parent);
+        for (var index = 0; index < count; index++)
+        {
+            var child = VisualTreeHelper.GetChild(parent, index);
+            if (child is T match)
+                yield return match;
+            foreach (var nested in child.Descendants<T>())
+                yield return nested;
+        }
+    }
+}
diff --git a/MainWindow.IoTesting.AutoConnect.cs b/MainWindow.IoTesting.AutoConnect.cs
index 81eb271..ba6e2d7 100644
--- a/MainWindow.IoTesting.AutoConnect.cs
+++ b/MainWindow.IoTesting.AutoConnect.cs
@@ -88,15 +88,29 @@ void ReportProgress(string message)
 
         try
         {
-            ReportProgress($"Connecting {ied.IedName} · {ied.IpAddress}:102");
             var usedSavedModel = false;
             if (!device.IsConnected)
             {
                 var canUseSavedModel = device.HasDiscoveryCache && device.Signals.Count > 0;
-                var connected = canUseSavedModel
-                    ? await ConnectUsingSavedModelAsync(device, selectDevice: false)
-                    : await ConnectAndConfigureDeviceAsync(device, openWizard: false, selectDevice: false);
-                usedSavedModel = connected && canUseSavedModel;
+                var connected = false;
+                if (canUseSavedModel)
+                {
+                    ReportProgress($"Fast reconnect {ied.IedName} · saved endpoint and discovery model");
+                    connected = await ConnectUsingSavedModelAsync(device, selectDevice: false);
+                    usedSavedModel = connected;
+                    if (!connected)
+                    {
+                        ReportProgress("Saved-model reconnect failed · running one full live discovery");
+                        connected = await ConnectAndConfigureDeviceAsync(device, openWizard: false, selectDevice: false);
+                        usedSavedModel = false;
+                    }
+                }
+                else
+                {
+                    ReportProgress($"Connecting {ied.IedName} · {ied.IpAddress}:102");
+                    connected = await ConnectAndConfigureDeviceAsync(device, openWizard: false, selectDevice: false);
+                }
+
                 if (!connected)
                 {
                     _ioTestLiveBindingService.Bind(project, Devices);
@@ -114,6 +128,10 @@ void ReportProgress(string message)
                     return IoTestSessionActionResult.Failure($"Full live-model discovery failed for {ied.IedName}.");
                 }
             }
+            else
+            {
+                ReportProgress($"{ied.IedName} association ready · reusing the loaded model");
+            }
 
             ReportProgress($"Matching {requestedPoints.Count} workbook signal(s)");
             var selection = _ioTestSignalSelectionService.Resolve(ied, device);
@@ -160,13 +178,13 @@ void ReportProgress(string message)
 
             if (device.IsMonitoring && (selectionChanged || !allRequestedPointsLive))
             {
-                ReportProgress("Refreshing acquisition for the workbook scope");
+                ReportProgress("Refreshing report acquisition for the workbook scope");
                 await StopDeviceMonitorAsync(device);
             }
 
             if (!device.IsMonitoring)
             {
-                ReportProgress("Arming configured RCB · dynamic URCB fallback if coverage is missing");
+                ReportProgress("Arming static RCB first · dynamic DataSet/URCB for uncovered points");
                 if (!await StartDeviceMonitorAsync(device, navigateToExplorer: false))
                 {
                     _ioTestLiveBindingService.Bind(project, Devices);
@@ -175,7 +193,12 @@ void ReportProgress(string message)
                 }
             }
 
-            await WaitForIoFatAcquisitionAsync(device, ReportProgress);
+            var acquisition = await SettleIoFatReportPriorityAsync(
+                project,
+                requestedPoints,
+                device,
+                ReportProgress,
+                allowSingleRestart: true);
 
             var binding = _ioTestLiveBindingService.Bind(project, Devices);
             var liveCount = requestedPoints.Count(point =>
@@ -192,12 +215,15 @@ void ReportProgress(string message)
 
             SaveSignalSelectionMemory(device);
             var modelText = usedSavedModel ? "saved model" : "live model";
-            var message = $"{ied.IedName} · {liveCount}/{requestedPoints.Count} live · {device.AcquisitionMode}";
+            var acquisitionText = acquisition.PollingCount == 0
+                ? $"report-backed {acquisition.ReportCount}/{requestedPoints.Count}"
+                : $"report-backed {acquisition.ReportCount}/{requestedPoints.Count} · MMS fallback {acquisition.PollingCount}";
+            var message = $"{ied.IedName} · {liveCount}/{requestedPoints.Count} live · {acquisitionText}";
             SetStatus(message);
             AddLog(
-                "INFO",
+                acquisition.PollingCount == 0 ? "INFO" : "WARN",
                 "IO Testing",
-                $"{message}. Acquisition policy: configured RCB → temporary dynamic DataSet/URCB → bounded MMS verification/fallback. No process control commands are enabled. Project live-bound={binding.LivePointCount}; model={modelText}.");
+                $"{message}. Acquisition policy: configured RCB → temporary dynamic DataSet/URCB → bounded MMS verification/fallback. No process control commands are enabled. Project live-bound={binding.LivePointCount}; model={modelText}; mode={device.AcquisitionMode}.");
             ReportProgress(message);
             return IoTestSessionActionResult.Success(message);
         }
@@ -222,25 +248,120 @@ void ReportProgress(string message)
         }
     }
 
-    private static async Task WaitForIoFatAcquisitionAsync(
+    private async Task<IoFatAcquisitionSummary> SettleIoFatReportPriorityAsync(
+        IoTestProject project,
+        IReadOnlyCollection<IoTestPointPlan> requestedPoints,
+        Iec61850MonitorDevice device,
+        Action<string> reportProgress,
+        bool allowSingleRestart)
+    {
+        var first = await ObserveIoFatAcquisitionAsync(
+            project,
+            requestedPoints,
+            device,
+            reportProgress,
+            TimeSpan.FromSeconds(8));
+
+        if (!allowSingleRestart ||
+            first.PollingCount == 0 ||
+            !device.AllowDynamicDataSetWrites ||
+            !device.IsMonitoring)
+        {
+            return first;
+        }
+
+        reportProgress($"{first.PollingCount} point(s) still on MMS fallback · rebuilding the report plan once");
+        await StopDeviceMonitorAsync(device);
+        await Task.Delay(180);
+        if (!await StartDeviceMonitorAsync(device, navigateToExplorer: false))
+            return first;
+
+        return await ObserveIoFatAcquisitionAsync(
+            project,
+            requestedPoints,
+            device,
+            reportProgress,
+            TimeSpan.FromSeconds(10));
+    }
+
+    private async Task<IoFatAcquisitionSummary> ObserveIoFatAcquisitionAsync(
+        IoTestProject project,
+        IReadOnlyCollection<IoTestPointPlan> requestedPoints,
         Iec61850MonitorDevice device,
-        Action<string> reportProgress)
+        Action<string> reportProgress,
+        TimeSpan timeout)
     {
-        if (!device.IsMonitoring)
-            return;
+        var deadline = DateTime.UtcNow + timeout;
+        var last = ReadIoFatAcquisitionSummary(requestedPoints, device);
+        var announced = false;
 
-        for (var attempt = 0; attempt < 35; attempt++)
+        while (DateTime.UtcNow < deadline && device.IsMonitoring)
         {
-            var mode = device.AcquisitionMode ?? string.Empty;
-            if (!mode.Contains("arming", StringComparison.OrdinalIgnoreCase) &&
-                !mode.Contains("live start", StringComparison.OrdinalIgnoreCase))
-                return;
-
-            if (attempt == 0)
-                reportProgress("Validating RCB/DataSet coverage · MMS remains verification only");
-            await Task.Delay(100);
+            await Task.Delay(120);
+            _ioTestLiveBindingService.Bind(project, Devices);
+            last = ReadIoFatAcquisitionSummary(requestedPoints, device);
+
+            if (!announced)
+            {
+                reportProgress("Validating static/dynamic report coverage · MMS is fallback only");
+                announced = true;
+            }
+
+            var plannerSettled = !ContainsPlannerStage(device.AcquisitionMode);
+            if (last.LiveCount == requestedPoints.Count &&
+                plannerSettled &&
+                last.UnknownCount == 0 &&
+                (last.PollingCount == 0 || DateTime.UtcNow >= deadline - TimeSpan.FromSeconds(2)))
+            {
+                break;
+            }
+        }
+
+        return last;
+    }
+
+    private static IoFatAcquisitionSummary ReadIoFatAcquisitionSummary(
+        IEnumerable<IoTestPointPlan> requestedPoints,
+        Iec61850MonitorDevice device)
+    {
+        var live = 0;
+        var report = 0;
+        var polling = 0;
+        var unknown = 0;
+
+        foreach (var point in requestedPoints)
+        {
+            if (point.LiveBindingState == IoTestLiveBindingState.LivePointReady)
+                live++;
+
+            var source = point.Runtime.CurrentSource ?? string.Empty;
+            if (IsReportSource(source))
+                report++;
+            else if (source.Contains("poll", StringComparison.OrdinalIgnoreCase) ||
+                     source.Contains("MMS", StringComparison.OrdinalIgnoreCase))
+                polling++;
+            else
+                unknown++;
         }
 
-        reportProgress($"Acquisition still settling · {device.AcquisitionMode}");
+        return new IoFatAcquisitionSummary(live, report, polling, unknown, device.AcquisitionMode ?? string.Empty);
     }
+
+    private static bool IsReportSource(string source)
+        => source.Contains("BRCB", StringComparison.OrdinalIgnoreCase) ||
+           source.Contains("URCB", StringComparison.OrdinalIgnoreCase) ||
+           source.Contains("report", StringComparison.OrdinalIgnoreCase);
+
+    private static bool ContainsPlannerStage(string? mode)
+        => (mode ?? string.Empty).Contains("arming", StringComparison.OrdinalIgnoreCase) ||
+           (mode ?? string.Empty).Contains("live start", StringComparison.OrdinalIgnoreCase) ||
+           (mode ?? string.Empty).Contains("preparing", StringComparison.OrdinalIgnoreCase) ||
+           (mode ?? string.Empty).Contains("settling", StringComparison.OrdinalIgnoreCase);
+
+    private sealed record IoFatAcquisitionSummary(
+        int LiveCount,
+        int ReportCount,
+        int PollingCount,
+        int UnknownCount,
+        string Mode);
 }
diff --git a/Services/IoTesting/IoFatReportPreviewService.cs b/Services/IoTesting/IoFatReportPreviewService.cs
new file mode 100644
index 0000000..80c46fb
--- /dev/null
+++ b/Services/IoTesting/IoFatReportPreviewService.cs
@@ -0,0 +1,130 @@
+// Copyright 2026 Ari Sulistiono
+// SPDX-License-Identifier: Apache-2.0
+
+using System.Globalization;
+using System.Net;
+using System.Text;
+using ArIED61850Tester.Models.IoTesting;
+
+namespace ArIED61850Tester.Services.IoTesting;
+
+/// <summary>
+/// Builds the in-workspace per-IED report preview. The preview follows the same
+/// NavigateToString/WebBrowser pattern used by the project-owned ARIEC60870 report
+/// preview while official PDF export remains the native PDF 1.4 writer.
+/// </summary>
+public static class IoFatReportPreviewService
+{
+    public static IoTestProject CreateIedScopedProject(IoTestProject project, IoTestIedPlan ied)
+    {
+        ArgumentNullException.ThrowIfNull(project);
+        ArgumentNullException.ThrowIfNull(ied);
+        if (!project.Ieds.Contains(ied))
+            throw new ArgumentException("The selected IED does not belong to this IO FAT project.", nameof(ied));
+
+        return new IoTestProject
+        {
+            ProjectId = project.ProjectId,
+            SchemaVersion = project.SchemaVersion,
+            ProjectName = project.ProjectName,
+            SourceWorkbookName = project.SourceWorkbookName,
+            SourceWorkbookSha256 = project.SourceWorkbookSha256,
+            ImportedAt = project.ImportedAt,
+            Ieds = new List<IoTestIedPlan> { ied }
+        };
+    }
+
+    public static string BuildHtml(
+        IoTestProject project,
+        IoTestIedPlan ied,
+        bool draft,
+        DateTimeOffset? generatedAt = null)
+    {
+        ArgumentNullException.ThrowIfNull(project);
+        ArgumentNullException.ThrowIfNull(ied);
+        var created = generatedAt ?? DateTimeOffset.Now;
+        var enabled = ied.TestPoints.Where(point => point.TestEnabled).ToList();
+        var passed = enabled.Count(point => point.Runtime.State == IoTestPointState.Passed);
+        var review = enabled.Count(point => point.Runtime.State == IoTestPointState.Review);
+        var failed = enabled.Count(point => point.Runtime.State == IoTestPointState.Failed);
+        var pending = Math.Max(0, enabled.Count - passed - review - failed);
+
+        var html = new StringBuilder(24_000);
+        html.AppendLine("<!doctype html><html><head><meta charset=\"utf-8\"/>");
+        html.AppendLine($"<title>{E(ied.IedName)} - ARSAS IO FAT Preview</title>");
+        html.AppendLine("<style>");
+        html.AppendLine("@page{size:A4 landscape;margin:10mm}*{box-sizing:border-box}body{margin:0;background:#e9eef5;color:#172033;font-family:'Segoe UI',Arial,sans-serif;font-size:11px}.sheet{width:1120px;min-height:760px;margin:22px auto;background:#fff;box-shadow:0 10px 32px rgba(31,45,71,.16);padding:30px 34px}.top{display:flex;justify-content:space-between;gap:24px;border-bottom:1px solid #dce5f0;padding-bottom:18px}.eyebrow{font-size:10px;font-weight:700;letter-spacing:.12em;color:#2f67d8}.title{font-size:25px;font-weight:700;margin-top:6px;color:#101827}.sub{margin-top:7px;color:#627086}.mark{min-width:170px;border:1px solid #ccd9eb;border-radius:12px;padding:12px 14px;text-align:right}.draft{color:#a85d00;background:#fff7e6;border-color:#eccb82}.final{color:#157347;background:#edf9f3;border-color:#9bd2b5}.mark b{display:block;font-size:17px}.meta{display:grid;grid-template-columns:1.3fr 1fr 1fr 1fr;margin:18px 0;border:1px solid #dfe7f1;border-radius:12px;overflow:hidden}.meta div{padding:11px 13px;border-right:1px solid #e6edf5}.meta div:last-child{border:0}.label{font-size:9px;font-weight:700;letter-spacing:.08em;color:#718096}.value{margin-top:4px;font-weight:600;color:#182235}.metrics{display:grid;grid-template-columns:repeat(5,1fr);gap:9px;margin-bottom:18px}.metric{border:1px solid #e1e8f1;border-radius:10px;padding:10px 12px}.metric span{font-size:9px;color:#728095;font-weight:700}.metric b{display:block;font-size:18px;margin-top:4px}.pass{color:#148052}.review{color:#9a6500}.fail{color:#c33b46}.pending{color:#637187}table{width:100%;border-collapse:collapse;table-layout:fixed}th{background:#f3f6fa;color:#596980;text-align:left;font-size:9px;letter-spacing:.04em;padding:9px 7px;border-bottom:1px solid #dbe4ef}td{padding:9px 7px;border-bottom:1px solid #e8edf4;vertical-align:top;overflow-wrap:anywhere}.mono{font-family:Consolas,'Courier New',monospace;font-size:9.5px;color:#46566d}.muted{color:#6f7d91}.result{font-weight:700}.footer{margin-top:18px;padding-top:10px;border-top:1px solid #e0e7f0;color:#69778b;font-size:9px;display:flex;justify-content:space-between}@media print{body{background:#fff}.sheet{width:auto;min-height:0;margin:0;box-shadow:none;padding:0}}");
+        html.AppendLine("</style></head><body><main class=\"sheet\">");
+        html.AppendLine("<section class=\"top\"><div>");
+        html.AppendLine("<div class=\"eyebrow\">ARSAS · IEC 61850 IO LIST FAT</div>");
+        html.AppendLine($"<div class=\"title\">{E(ied.IedName)} evidence report</div>");
+        html.AppendLine($"<div class=\"sub\">{E(project.ProjectName)} · relay-timestamped OFF → ON → OFF verification</div></div>");
+        html.AppendLine(draft
+            ? "<div class=\"mark draft\"><span class=\"label\">PREVIEW STATUS</span><b>DRAFT / LIVE</b><span>Stop the active session before issuing the final PDF.</span></div>"
+            : "<div class=\"mark final\"><span class=\"label\">PREVIEW STATUS</span><b>SEALED VIEW</b><span>Ready for per-IED PDF export.</span></div>");
+        html.AppendLine("</section>");
+
+        html.AppendLine("<section class=\"meta\">");
+        Meta(html, "IED", ied.IedName);
+        Meta(html, "IP ADDRESS", ied.IpAddress);
+        Meta(html, "PROJECT ID", project.ProjectId);
+        Meta(html, "GENERATED", created.ToString("yyyy-MM-dd HH:mm:ss zzz", CultureInfo.InvariantCulture));
+        html.AppendLine("</section>");
+
+        html.AppendLine("<section class=\"metrics\">");
+        Metric(html, "TEST POINTS", enabled.Count, string.Empty);
+        Metric(html, "PASS", passed, "pass");
+        Metric(html, "REVIEW", review, "review");
+        Metric(html, "FAILED", failed, "fail");
+        Metric(html, "PENDING", pending, "pending");
+        html.AppendLine("</section>");
+
+        html.AppendLine("<table><colgroup><col style=\"width:15%\"><col style=\"width:22%\"><col style=\"width:8%\"><col style=\"width:10%\"><col style=\"width:13%\"><col style=\"width:13%\"><col style=\"width:8%\"><col style=\"width:11%\"></colgroup>");
+        html.AppendLine("<thead><tr><th>SIGNAL</th><th>IEC 61850 REFERENCE</th><th>VALUE</th><th>ACQUISITION</th><th>ON · RELAY TIME</th><th>OFF · RELAY TIME</th><th>RESULT</th><th>STATUS / REASON</th></tr></thead><tbody>");
+        foreach (var point in enabled)
+        {
+            var result = Result(point.Runtime.State);
+            html.AppendLine("<tr>");
+            Cell(html, point.SignalName);
+            Cell(html, point.ObjectReference, "mono");
+            Cell(html, $"{point.Runtime.CurrentValue} · {point.Runtime.CurrentQuality}");
+            Cell(html, point.Runtime.CurrentSource);
+            Cell(html, point.Runtime.OnRelayTimestampText, "mono");
+            Cell(html, point.Runtime.OffRelayTimestampText, "mono");
+            Cell(html, result.Text, $"result {result.Css}");
+            Cell(html, $"{point.Runtime.StateText} · {point.Runtime.StatusReason}", "muted");
+            html.AppendLine("</tr>");
+        }
+        if (enabled.Count == 0)
+            html.AppendLine("<tr><td colspan=\"8\" class=\"muted\">No enabled IO-list test points are available for this IED.</td></tr>");
+        html.AppendLine("</tbody></table>");
+        html.AppendLine($"<footer class=\"footer\"><span>Workbook: {E(project.SourceWorkbookName)} · SHA-256 {E(ShortHash(project.SourceWorkbookSha256))}</span><span>ARSAS per-IED print preview</span></footer>");
+        html.AppendLine("</main></body></html>");
+        return html.ToString();
+    }
+
+    private static void Meta(StringBuilder html, string label, string value)
+        => html.AppendLine($"<div><span class=\"label\">{E(label)}</span><div class=\"value\">{E(value)}</div></div>");
+
+    private static void Metric(StringBuilder html, string label, int value, string css)
+        => html.AppendLine($"<div class=\"metric\"><span>{E(label)}</span><b class=\"{css}\">{value.ToString(CultureInfo.InvariantCulture)}</b></div>");
+
+    private static void Cell(StringBuilder html, string? value, string css = "")
+        => html.AppendLine($"<td class=\"{css}\">{E(string.IsNullOrWhiteSpace(value) ? "—" : value)}</td>");
+
+    private static (string Text, string Css) Result(IoTestPointState state) => state switch
+    {
+        IoTestPointState.Passed => ("✔ PASS", "pass"),
+        IoTestPointState.Review => ("⚠ REVIEW", "review"),
+        IoTestPointState.Failed => ("✖ FAILED", "fail"),
+        _ => ("—", "pending")
+    };
+
+    private static string E(string? value) => WebUtility.HtmlEncode(value ?? string.Empty);
+
+    private static string ShortHash(string? value)
+    {
+        var normalized = value?.Trim() ?? string.Empty;
+        return normalized.Length <= 16 ? normalized : normalized[..16] + "…";
+    }
+}
diff --git a/tests/ARSAS.Tests/IoFatReportPreviewServiceTests.cs b/tests/ARSAS.Tests/IoFatReportPreviewServiceTests.cs
new file mode 100644
index 0000000..4132d03
--- /dev/null
+++ b/tests/ARSAS.Tests/IoFatReportPreviewServiceTests.cs
@@ -0,0 +1,128 @@
+using ArIED61850Tester.Models.IoTesting;
+using ArIED61850Tester.Services.IoTesting;
+
+namespace ARSAS.Tests;
+
+public sealed class IoFatReportPreviewServiceTests
+{
+    [Fact]
+    public void BuildHtml_IsScopedToSelectedIed_AndMarksLiveSessionDraft()
+    {
+        var selected = BuildIed("IED_A", "192.168.1.10", "TP-A");
+        var other = BuildIed("IED_B", "192.168.1.11", "TP-B");
+        var project = BuildProject(selected, other);
+
+        var html = IoFatReportPreviewService.BuildHtml(
+            project,
+            selected,
+            draft: true,
+            new DateTimeOffset(2026, 7, 29, 7, 0, 0, TimeSpan.Zero));
+
+        Assert.Contains("IED_A evidence report", html, StringComparison.Ordinal);
+        Assert.Contains("TP-A", html, StringComparison.Ordinal);
+        Assert.Contains("DRAFT / LIVE", html, StringComparison.Ordinal);
+        Assert.DoesNotContain("IED_B", html, StringComparison.Ordinal);
+        Assert.DoesNotContain("TP-B", html, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void BuildHtml_EncodesImportedText()
+    {
+        var ied = BuildIed("IED<&>", "192.168.1.20", "Signal <unsafe>");
+        var html = IoFatReportPreviewService.BuildHtml(BuildProject(ied), ied, draft: false);
+
+        Assert.Contains("IED&lt;&amp;&gt;", html, StringComparison.Ordinal);
+        Assert.Contains("Signal &lt;unsafe&gt;", html, StringComparison.Ordinal);
+        Assert.DoesNotContain("Signal <unsafe>", html, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void CreateIedScopedProject_PreservesIdentityAndOnlySelectedIed()
+    {
+        var first = BuildIed("IED_A", "192.168.1.10", "TP-A");
+        var second = BuildIed("IED_B", "192.168.1.11", "TP-B");
+        var project = BuildProject(first, second);
+
+        var scoped = IoFatReportPreviewService.CreateIedScopedProject(project, second);
+
+        Assert.Equal(project.ProjectId, scoped.ProjectId);
+        Assert.Equal(project.SourceWorkbookSha256, scoped.SourceWorkbookSha256);
+        Assert.Single(scoped.Ieds);
+        Assert.Same(second, scoped.Ieds[0]);
+    }
+
+    [Fact]
+    public void PreviewWorkspace_PortsAriecBrowserPattern_AndKeepsProgressOnIedCard()
+    {
+        var previewSource = File.ReadAllText(FindRepoFile("IoListTestingWindow.PrintPreview.cs"));
+        var xaml = File.ReadAllText(FindRepoFile("IoListTestingWindow.xaml"));
+
+        Assert.Contains("WebBrowser", previewSource, StringComparison.Ordinal);
+        Assert.Contains("NavigateToString", previewSource, StringComparison.Ordinal);
+        Assert.Contains("Print Preview", previewSource, StringComparison.Ordinal);
+        Assert.Contains("CreateIedScopedProject", previewSource, StringComparison.Ordinal);
+        Assert.Contains("RemoveMainPreparationSurface", previewSource, StringComparison.Ordinal);
+        Assert.Contains("workspaceGrid.Children.Remove(preparationSurface)", previewSource, StringComparison.Ordinal);
+        Assert.Contains("ClearStalePreparationFlags", previewSource, StringComparison.Ordinal);
+        Assert.Contains("CardProgress", xaml, StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void IoFatPreparation_UsesCachedReconnect_AndRetriesReportPlanBeforePollingFallback()
+    {
+        var source = File.ReadAllText(FindRepoFile("MainWindow.IoTesting.AutoConnect.cs"));
+
+        Assert.Contains("Fast reconnect", source, StringComparison.Ordinal);
+        Assert.Contains("ConnectUsingSavedModelAsync", source, StringComparison.Ordinal);
+        Assert.Contains("SettleIoFatReportPriorityAsync", source, StringComparison.Ordinal);
+        Assert.Contains("rebuilding the report plan once", source, StringComparison.Ordinal);
+        Assert.Contains("configured RCB → temporary dynamic DataSet/URCB", source, StringComparison.Ordinal);
+        Assert.Contains("IsReportSource", source, StringComparison.Ordinal);
+        Assert.DoesNotContain("ExecuteControlAsync", source, StringComparison.Ordinal);
+    }
+
+    private static IoTestProject BuildProject(params IoTestIedPlan[] ieds) => new()
+    {
+        ProjectId = "PROJECT-1",
+        SchemaVersion = "ARSAS-FAT-IO-1.0",
+        ProjectName = "Preview Project",
+        SourceWorkbookName = "source.xlsx",
+        SourceWorkbookSha256 = "abcdef0123456789abcdef0123456789",
+        Ieds = ieds.ToList()
+    };
+
+    private static IoTestIedPlan BuildIed(string name, string ip, string signalName) => new()
+    {
+        IedName = name,
+        IpAddress = ip,
+        TestPoints = new List<IoTestPointPlan>
+        {
+            new()
+            {
+                TestPointId = $"{name}-TP-1",
+                IedName = name,
+                IpAddress = ip,
+                SignalName = signalName,
+                ObjectReference = $"{name}LD/GGIO1.Ind1.stVal",
+                FunctionalConstraint = "ST",
+                ExpectedOnText = "true",
+                ExpectedOffText = "false"
+            }
+        }
+    };
+
+    private static string FindRepoFile(string relativePath)
+    {
+        DirectoryInfo? directory = new(AppContext.BaseDirectory);
+        while (directory != null)
+        {
+            var candidate = Path.Combine(directory.FullName, relativePath);
+            if (File.Exists(candidate))
+                return candidate;
+            directory = directory.Parent;
+        }
+
+        throw new FileNotFoundException(
+            $"Could not locate repository file '{relativePath}' from '{AppContext.BaseDirectory}'.");
+    }
+}
diff --git a/tests/ARSAS.Tests/IoTestingUiContractTests.cs b/tests/ARSAS.Tests/IoTestingUiContractTests.cs
index a26be24..afe485e 100644
--- a/tests/ARSAS.Tests/IoTestingUiContractTests.cs
+++ b/tests/ARSAS.Tests/IoTestingUiContractTests.cs
@@ -103,7 +103,8 @@ public void IoFatAutomaticPreparation_UsesSmartReportingWithoutProcessControls()
         Assert.Contains("configured RCB", source, StringComparison.Ordinal);
         Assert.Contains("dynamic DataSet/URCB", source, StringComparison.Ordinal);
         Assert.Contains("bounded MMS verification/fallback", source, StringComparison.Ordinal);
-        Assert.Contains("WaitForIoFatAcquisitionAsync", source, StringComparison.Ordinal);
+        Assert.Contains("SettleIoFatReportPriorityAsync", source, StringComparison.Ordinal);
+        Assert.Contains("rebuilding the report plan once", source, StringComparison.Ordinal);
         Assert.DoesNotContain("ExecuteControlAsync", source, StringComparison.Ordinal);
         Assert.DoesNotContain("InspectControlAsync", source, StringComparison.Ordinal);
     }