feat: add editable register monitoring

app/src/domain/virtual_register_repository.cpp

@@ -85,3 +85,9 @@ void VirtualRegisterRepository::clear()
     bits_.fill(false);
     words_.fill(0);
 }
+
+void VirtualRegisterRepository::copyFrom(const VirtualRegisterRepository &source)
+{
+    bits_ = source.bits_;
+    words_ = source.words_;
+}

app/src/domain/virtual_register_repository.h

@@ -27,6 +27,8 @@ public:
 
     // 将所有虚拟寄存器恢复为默认值，开始新的离线会话
     void clear();
+    // 从另一份虚拟寄存器复制完整的 M/D 快照
+    void copyFrom(const VirtualRegisterRepository &source);
 
 private:
     static constexpr std::size_t kRegisterCount =

app/src/main.cpp

@@ -60,6 +60,8 @@ int main(int argc, char *argv[])
 
     // 在内存中保存离线仿真使用的 M、D 寄存器值，不会写入真实 PLC
     VirtualRegisterRepository virtual_register_repository;
+    // 保存编辑态确认的离线初始值，不参与仿真扫描和工程持久化
+    VirtualRegisterRepository offline_initial_repository;
     // 保存从真实 PLC 最近一次读取到的 M、D 值，并转交写入请求
     PlcRegisterRepository plc_register_repository;
     // 给界面提供统一的寄存器入口，启动时先使用上面的离线寄存器
@@ -79,8 +81,11 @@ int main(int argc, char *argv[])
     RegisterCommentService register_comment_service(project_service);
     // 处理自由监控列表中的寄存器读取和单点写入
     RegisterMonitorService register_monitor_service(active_register_repository);
+    register_monitor_service.setOfflineInitialRepository(offline_initial_repository);
+    register_monitor_service.setOfflineInitialCaptureEnabled(true);
     // 用虚拟寄存器执行本地梯形图，实现不连接 PLC 的离线仿真
-    OfflineSimulationService offline_simulation_service(virtual_register_repository);
+    OfflineSimulationService offline_simulation_service(
+        virtual_register_repository, &offline_initial_repository);
     // 从 PLC 缓存推算本地梯形图轨迹，输出只写内部临时仓库
     OnlineLogicMonitorService online_logic_monitor_service(plc_register_repository);
     // 管理三种运行模式，并控制离线仿真和真机只读轨迹的生命周期

app/src/services/offline_simulation_service.cpp

@@ -4,9 +4,11 @@
 
 OfflineSimulationService::OfflineSimulationService(
     VirtualRegisterRepository &repository,
+    VirtualRegisterRepository *initial_repository,
     QObject *parent)
     : QObject(parent),
-      repository_(repository)
+      repository_(repository),
+      initial_repository_(initial_repository)
 {
     timer_.setInterval(kDefaultScanIntervalMs);
     timer_.setTimerType(Qt::PreciseTimer);
@@ -31,10 +33,14 @@ SimulationStartResult OfflineSimulationService::start(
         return {false, SimulationStartError::InvalidLogic, validation};
     }
 
-    // 重启会话时清空沿触发状态和虚拟 M/D，避免继承上次运行现场
+    // 重启会话时清空沿触发状态和运行值，再装载编辑态确认的初始值
     timer_.stop();
     executor_.resetRuntime();
     repository_.clear();
+    if (initial_repository_ != nullptr)
+    {
+        repository_.copyFrom(*initial_repository_);
+    }
     logic_snapshot_ = std::move(snapshot);
     successful_scan_count_ = 0;
     last_error_ = {true, LogicScanError::None, {}, {}, {}, {}};
@@ -45,6 +51,15 @@ SimulationStartResult OfflineSimulationService::start(
     return {true, SimulationStartError::None, {true, LogicScanError::None, {}, {}, {}, {}}};
 }
 
+void OfflineSimulationService::restoreInitialValues()
+{
+    repository_.clear();
+    if (initial_repository_ != nullptr)
+    {
+        repository_.copyFrom(*initial_repository_);
+    }
+}
+
 void OfflineSimulationService::stop()
 {
     timer_.stop();
@@ -54,6 +69,8 @@ void OfflineSimulationService::stop()
     {
         return;
     }
+    // 运行结束后丢弃本轮输出，编辑态继续看到下一轮要使用的初始值
+    restoreInitialValues();
     state_ = SimulationState::Stopped;
     last_error_ = {true, LogicScanError::None, {}, {}, {}, {}};
     emit stateChanged();

app/src/services/offline_simulation_service.h

@@ -45,10 +45,12 @@ public:
     /**
      * @brief 创建离线仿真服务
      * @param repository 离线模式使用的虚拟 M/D 寄存器仓库
+     * @param initial_repository 编辑态确认的离线初始值仓库，可为空以保持旧的全清零行为
      * @param parent Qt 对象父级
      */
     explicit OfflineSimulationService(
         VirtualRegisterRepository &repository,
+        VirtualRegisterRepository *initial_repository = nullptr,
         QObject *parent = nullptr);
 
     // 复制工程逻辑作为本次会话快照并启动定时扫描；启动失败时不进入运行态
@@ -57,6 +59,8 @@ public:
     void stop();
     // 立即执行一轮扫描；非 Running 状态调用会返回失败结果
     LogicScanResult executeOnce();
+    // 将当前会话的离线初始值恢复到运行仓库
+    void restoreInitialValues();
 
     // 返回当前离线仿真生命周期状态
     SimulationState state() const;
@@ -82,6 +86,7 @@ private:
     void enterFault(const LogicScanResult &error);
 
     VirtualRegisterRepository &repository_; // 不拥有的虚拟寄存器仓库
+    VirtualRegisterRepository *initial_repository_ = nullptr; // 不拥有的离线初始值仓库
     SoftwareLogicExecutor executor_; // 执行逻辑校验和扫描的领域执行器
     QTimer timer_; // 按固定周期触发离线扫描
     std::vector<ControlLogic> logic_snapshot_; // 本次仿真使用的逻辑快照

app/src/services/register_monitor_service.cpp

@@ -1,5 +1,7 @@
 #include "register_monitor_service.h"
 
+#include "domain/virtual_register_repository.h"
+
 #include <algorithm>
 #include <cmath>
 #include <optional>
@@ -31,6 +33,17 @@ RegisterMonitorService::RegisterMonitorService(RegisterRepository &repository)
 {
 }
 
+void RegisterMonitorService::setOfflineInitialRepository(
+    VirtualRegisterRepository &repository)
+{
+    offline_initial_repository_ = &repository;
+}
+
+void RegisterMonitorService::setOfflineInitialCaptureEnabled(bool enabled)
+{
+    capture_offline_initial_values_ = enabled;
+}
+
 RegisterMonitorResult RegisterMonitorService::addRange(
     const std::string &start_address, int count)
 {
@@ -175,34 +188,32 @@ RegisterMonitorWriteResult RegisterMonitorService::writeBit(
     const RegisterAddress &address, bool value)
 {
     const RegisterWriteResult result = repository_.writeBit(address, value);
-    if (result.succeeded)
-    {
-        return {true, RegisterError::None, {}};
-    }
-    return {false, result.error, result.error == RegisterError::AreaMismatch
+    const RegisterMonitorWriteResult active_result = result.succeeded
+        ? RegisterMonitorWriteResult{true, RegisterError::None, {}}
+        : RegisterMonitorWriteResult{false, result.error, result.error == RegisterError::AreaMismatch
         ? "位写入只允许访问 M 区"
         : result.error == RegisterError::InvalidAddress
             ? "写入地址无效"
             : result.error == RegisterError::Unavailable
                 ? "当前寄存器源不可用"
                 : "寄存器写入请求被拒绝"};
+    return captureInitialBit(address, value, active_result);
 }
 
 RegisterMonitorWriteResult RegisterMonitorService::writeWord(
     const RegisterAddress &address, std::int16_t value)
 {
     const RegisterWriteResult result = repository_.writeWord(address, value);
-    if (result.succeeded)
-    {
-        return {true, RegisterError::None, {}};
-    }
-    return {false, result.error, result.error == RegisterError::AreaMismatch
+    const RegisterMonitorWriteResult active_result = result.succeeded
+        ? RegisterMonitorWriteResult{true, RegisterError::None, {}}
+        : RegisterMonitorWriteResult{false, result.error, result.error == RegisterError::AreaMismatch
         ? "字写入只允许访问 D 区"
         : result.error == RegisterError::InvalidAddress
             ? "写入地址无效"
             : result.error == RegisterError::Unavailable
                 ? "当前寄存器源不可用"
                 : "寄存器写入请求被拒绝"};
+    return captureInitialWord(address, value, active_result);
 }
 
 RegisterMonitorWriteResult RegisterMonitorService::writeFloat(
@@ -216,12 +227,51 @@ RegisterMonitorWriteResult RegisterMonitorService::writeFloat(
     }
     const RegisterWriteResult result = repository_.writeWordPair(
         address, Float32Codec::encode(value));
-    if (result.succeeded)
+    const RegisterMonitorWriteResult active_result = result.succeeded
+        ? RegisterMonitorWriteResult{true, RegisterError::None, {}}
+        : RegisterMonitorWriteResult{false, result.error, result.error == RegisterError::Unavailable
+            ? "当前寄存器源不可用" : "寄存器写入请求被拒绝"};
+    return captureInitialFloat(address, value, active_result);
+}
+
+RegisterMonitorWriteResult RegisterMonitorService::captureInitialBit(
+    const RegisterAddress &address, bool value,
+    const RegisterMonitorWriteResult &active_result)
+{
+    if (!active_result.succeeded || !capture_offline_initial_values_
+        || offline_initial_repository_ == nullptr)
+    {
+        return active_result;
+    }
+    offline_initial_repository_->writeBit(address, value);
+    return active_result;
+}
+
+RegisterMonitorWriteResult RegisterMonitorService::captureInitialWord(
+    const RegisterAddress &address, std::int16_t value,
+    const RegisterMonitorWriteResult &active_result)
+{
+    if (!active_result.succeeded || !capture_offline_initial_values_
+        || offline_initial_repository_ == nullptr)
     {
-        return {true, RegisterError::None, {}};
+        return active_result;
     }
-    return {false, result.error, result.error == RegisterError::Unavailable
-        ? "当前寄存器源不可用" : "寄存器写入请求被拒绝"};
+    offline_initial_repository_->writeWord(address, value);
+    return active_result;
+}
+
+RegisterMonitorWriteResult RegisterMonitorService::captureInitialFloat(
+    const RegisterAddress &address, float value,
+    const RegisterMonitorWriteResult &active_result)
+{
+    if (!active_result.succeeded || !capture_offline_initial_values_
+        || offline_initial_repository_ == nullptr)
+    {
+        return active_result;
+    }
+    offline_initial_repository_->writeWordPair(
+        address, Float32Codec::encode(value));
+    return active_result;
 }
 
 const std::vector<RegisterAddress> &RegisterMonitorService::addresses() const

app/src/services/register_monitor_service.h

@@ -8,6 +8,8 @@
 #include <string>
 #include <vector>
 
+class VirtualRegisterRepository;
+
 // 自由监控列表编辑的失败分类
 enum class RegisterMonitorError
 {
@@ -38,7 +40,7 @@ struct RegisterMonitorWriteResult
 /**
  * @brief 编排自由监控地址列表和寄存器仓库读写
  *
- * 地址列表只属于当前运行会话，不写入工程文件；仓库由当前运行模式注入
+ * 地址列表和离线初始值只属于当前运行会话，不写入工程文件；仓库由当前运行模式注入
  */
 class RegisterMonitorService
 {
@@ -49,6 +51,11 @@ public:
      */
     explicit RegisterMonitorService(RegisterRepository &repository);
 
+    // 配置编辑态离线初始值仓库；该仓库只保存在当前进程内
+    void setOfflineInitialRepository(VirtualRegisterRepository &repository);
+    // 编辑态开启时，监控写入同时更新离线初始值
+    void setOfflineInitialCaptureEnabled(bool enabled);
+
     /**
      * @brief 从起始地址连续添加同一区域的多个地址
      * @param start_address 文本地址，例如 M0 或 D100
@@ -108,7 +115,19 @@ public:
     void setAddressesChangedCallback(std::function<void()> callback);
 
 private:
+    RegisterMonitorWriteResult captureInitialBit(
+        const RegisterAddress &address, bool value,
+        const RegisterMonitorWriteResult &active_result);
+    RegisterMonitorWriteResult captureInitialWord(
+        const RegisterAddress &address, std::int16_t value,
+        const RegisterMonitorWriteResult &active_result);
+    RegisterMonitorWriteResult captureInitialFloat(
+        const RegisterAddress &address, float value,
+        const RegisterMonitorWriteResult &active_result);
+
     RegisterRepository &repository_; // 当前运行模式的寄存器仓库，不由服务拥有
+    VirtualRegisterRepository *offline_initial_repository_ = nullptr;
+    bool capture_offline_initial_values_ = false;
     RegisterMonitorModel model_; // 当前会话的去重监控地址列表
     std::function<void()> addresses_changed_callback_; // 地址变化后的轮询刷新通知
 };

app/src/ui/free_monitor_widget.cpp

@@ -73,7 +73,12 @@ void FreeMonitorWidget::refreshValues(
     QString source = tr("数据源：未启用");
     bool values_available = false;
     bool communication_fault = false;
-    if (mode == ApplicationMode::OfflineRunning)
+    if (mode == ApplicationMode::Editing)
+    {
+        source = tr("数据源：离线初始值 · 虚拟 M/D");
+        values_available = true;
+    }
+    else if (mode == ApplicationMode::OfflineRunning)
     {
         source = tr("数据源：虚拟 M/D");
         values_available = true;

app/src/ui/free_monitor_widget.h

@@ -34,7 +34,7 @@ public:
     /** 释放 Designer 界面对象 */
     ~FreeMonitorWidget() override;
 
-    /** 真机未连接、通信故障或编辑态时应关闭写入入口 */
+    /** 根据当前模式和通信状态开启或关闭写入入口 */
     void setWriteEnabled(bool enabled);
     /** 根据运行模式和 PLC 状态刷新所有监控值 */
     void refreshValues(ApplicationMode mode, PlcConnectionState plc_state);

app/src/ui/main_window.cpp

@@ -6,6 +6,7 @@
 #include "logic_editor_widget.h"
 #include "logic_instruction_dialog.h"
 #include "plc_connection_dialog.h"
+#include "free_monitor_widget.h"
 #include "runtime_monitor_widget.h"
 #include "toolbar_icon_factory.h"
 #include "project_workspace_controller.h"
@@ -30,6 +31,7 @@
 #include <QApplication>
 #include <QCloseEvent>
 #include <QDialogButtonBox>
+#include <QDockWidget>
 #include <QEvent>
 #include <QFileDialog>
 #include <QGraphicsScene>
@@ -352,6 +354,7 @@ void MainWindow::initializeUi()
     configureHmiEditor();
     configureLogicEditor();
     configureRuntimeMonitor();
+    configureDataMonitor();
     configureProjectTree();
     runtime_mode_service_.setPlcStatusChangedCallback(
         [this] { schedulePlcStatusUpdate(); });
@@ -384,6 +387,7 @@ void MainWindow::initializeUi()
 MainWindow::~MainWindow()
 {
     qApp->removeEventFilter(this);
+    register_monitor_service_.setAddressesChangedCallback({});
     runtime_mode_service_.setPlcStatusChangedCallback({});
 }
 
@@ -871,6 +875,77 @@ void MainWindow::configureRuntimeMonitor()
     runtime_monitor_widget_ = runtime_panel_controller_->runtimeMonitorWidget();
 }
 
+void MainWindow::configureDataMonitor()
+{
+    data_monitor_dock_ = ui_->dataMonitorDock;
+    data_monitor_widget_ = new FreeMonitorWidget(
+        register_monitor_service_, data_monitor_dock_);
+    data_monitor_widget_->setObjectName(QStringLiteral("dataMonitorWidget"));
+    ui_->dataMonitorDockLayout->addWidget(data_monitor_widget_);
+    ui_->viewMenu->addAction(data_monitor_dock_->toggleViewAction());
+
+    connect(data_monitor_widget_, &FreeMonitorWidget::monitorAddressesChanged,
+            this,
+            [this]
+            {
+                runtime_mode_service_.setMonitorAddresses(
+                    register_monitor_service_.pollAddresses(),
+                    register_monitor_service_.float32Starts());
+                refreshDataMonitorUi();
+            });
+    connect(data_monitor_widget_, &FreeMonitorWidget::operationMessage,
+            this,
+            [this](const QString &message)
+            {
+                statusBar()->showMessage(message, 4000);
+                appendOutputMessage(message);
+            });
+    register_monitor_service_.setAddressesChangedCallback(
+        [this]
+        {
+            if (data_monitor_widget_ != nullptr)
+            {
+                data_monitor_widget_->reloadAddresses();
+            }
+            if (runtime_monitor_widget_ != nullptr
+                && runtime_monitor_widget_->freeMonitorWidget() != nullptr)
+            {
+                runtime_monitor_widget_->freeMonitorWidget()->reloadAddresses();
+            }
+            runtime_mode_service_.setMonitorAddresses(
+                register_monitor_service_.pollAddresses(),
+                register_monitor_service_.float32Starts());
+        });
+    data_monitor_refresh_timer_ = new QTimer(this);
+    data_monitor_refresh_timer_->setInterval(150);
+    connect(data_monitor_refresh_timer_, &QTimer::timeout,
+            this, &MainWindow::refreshDataMonitorUi);
+    data_monitor_refresh_timer_->start();
+    refreshDataMonitorUi();
+}
+
+void MainWindow::refreshDataMonitorUi()
+{
+    if (data_monitor_widget_ == nullptr)
+    {
+        return;
+    }
+    const ApplicationMode mode = runtime_mode_service_.mode();
+    const bool online_connected = mode == ApplicationMode::OnlineRunning
+        && runtime_mode_service_.plcConnectionState()
+            == PlcConnectionState::Connected;
+    data_monitor_widget_->setWriteEnabled(
+        mode == ApplicationMode::Editing
+        || mode == ApplicationMode::OfflineRunning
+        || online_connected);
+    data_monitor_widget_->refreshValues(
+        mode, runtime_mode_service_.plcConnectionState());
+    if (data_monitor_dock_ != nullptr)
+    {
+        data_monitor_dock_->setVisible(mode == ApplicationMode::Editing);
+    }
+}
+
 void MainWindow::configureProjectTree()
 {
     project_workspace_controller_ = std::make_unique<ProjectWorkspaceController>(
@@ -1751,6 +1826,8 @@ void MainWindow::updateModeUi(const QString &message)
     // 按服务层策略统一启用/禁用编辑入口，避免单个按钮遗漏状态同步
     const ApplicationMode mode = runtime_mode_service_.mode();
     const ModePolicy policy = runtime_mode_service_.policy();
+    register_monitor_service_.setOfflineInitialCaptureEnabled(
+        mode == ApplicationMode::Editing);
     restoreCurrentModeAction();
     const bool running = mode != ApplicationMode::Editing;
     if (running)
@@ -1869,6 +1946,7 @@ void MainWindow::updateModeUi(const QString &message)
         register_status_label_->setText(tr("PLC：通信故障"));
     }
     updateSimulationUi(false);
+    refreshDataMonitorUi();
     statusBar()->showMessage(message, 4000);
     const bool duplicate = ui_->outputList->count() > 0
         && ui_->outputList->item(ui_->outputList->count() - 1)->text() == message;

app/src/ui/main_window.h

@@ -26,6 +26,8 @@ class QActionGroup;
 class QCloseEvent;
 class QEvent;
 class QLabel;
+class QDockWidget;
+class QTimer;
 
 namespace Ui {
 class MainWindow;
@@ -46,6 +48,7 @@ class LogicEditorWidget;
 class RegisterMonitorService;
 class PlcDiscoveryGateway;
 class RuntimeMonitorWidget;
+class FreeMonitorWidget;
 class ProjectWorkspaceController;
 class PropertyPanelController;
 class RuntimePanelController;
@@ -127,6 +130,8 @@ private:
     void configureLogicEditor();
     /** 创建并连接运行监控面板 */
     void configureRuntimeMonitor();
+    /** 创建并连接编辑态数据监控面板 */
+    void configureDataMonitor();
     /** 创建并连接工程树 */
     void configureProjectTree();
     /** 创建并连接控件属性编辑表单 */
@@ -232,6 +237,8 @@ private:
     void restoreCurrentModeAction();
     /** 完成主窗口初始化和首次界面刷新 */
     void initializeUi();
+    /** 刷新编辑态数据监控的模式、权限和当前值 */
+    void refreshDataMonitorUi();
 
     /** Qt Designer 生成的主窗口界面对象 */
     std::unique_ptr<Ui::MainWindow> ui_;
@@ -279,6 +286,10 @@ private:
     LogicEditorWidget *logic_editor_widget_ = nullptr;
     /** 唯一的运行监控控件 */
     RuntimeMonitorWidget *runtime_monitor_widget_ = nullptr;
+    /** 主窗口中的数据监控面板 */
+    QDockWidget *data_monitor_dock_ = nullptr;
+    FreeMonitorWidget *data_monitor_widget_ = nullptr;
+    QTimer *data_monitor_refresh_timer_ = nullptr;
     /** 显示当前运行模式的状态标签 */
     QLabel *mode_status_label_ = nullptr;
     /** 显示 PLC 连接状态的标签 */

app/src/ui/main_window.ui

@@ -905,6 +905,28 @@
     </layout>
    </widget>
   </widget>
+  <widget class="QDockWidget" name="dataMonitorDock">
+   <property name="minimumSize">
+    <size>
+     <width>640</width>
+     <height>220</height>
+    </size>
+   </property>
+   <property name="windowTitle">
+    <string>数据监控</string>
+   </property>
+   <attribute name="dockWidgetArea">
+    <number>2</number>
+   </attribute>
+   <widget class="QWidget" name="dataMonitorDockContents">
+    <layout class="QVBoxLayout" name="dataMonitorDockLayout">
+     <property name="leftMargin"><number>6</number></property>
+     <property name="topMargin"><number>6</number></property>
+     <property name="rightMargin"><number>6</number></property>
+     <property name="bottomMargin"><number>6</number></property>
+    </layout>
+   </widget>
+  </widget>
   <widget class="QDockWidget" name="outputDock">
    <property name="minimumSize">
     <size>

app/src/ui/runtime_panel_controller.cpp

@@ -157,9 +157,10 @@ void RuntimePanelController::enterRuntime(
     if (!runtime_session_active_)
     {
         runtime_monitor_widget_->setProjectObjects(page_id, logic_id);
-    // 运行窗口只创建一次，后续进入运行态复用同一个监控投影
-    runtime_session_active_ = true;
+        // 运行窗口只创建一次，后续进入运行态复用同一个监控投影
+        runtime_session_active_ = true;
     }
+    runtime_monitor_widget_->freeMonitorWidget()->reloadAddresses();
     runtime_monitor_widget_->setMode(mode, plc_state);
     runtime_monitor_window_->showForRuntime();
 }

app/tests/offline_simulation_service_tests.cpp

@@ -660,6 +660,37 @@ void testSimulationLifecycleSnapshotAndFault()
     simulation.stop();
 }
 
+void testSimulationUsesInitialValuesAndDiscardsRuntimeOutputs()
+{
+    VirtualRegisterRepository repository;
+    VirtualRegisterRepository initial_repository;
+    OfflineSimulationService simulation(repository, &initial_repository);
+    const ControlLogic program = logic({
+        rung("initial-rung", {{contact("initial-input", 0)}}, coil("runtime-output", 1))});
+
+    writeBit(initial_repository, 0, true);
+    writeWord(initial_repository, 10, 321);
+    require(simulation.start({program}).succeeded,
+            "simulation must start from the explicit initial repository");
+    require(readBit(repository, 0)
+                && readWord(repository, 10) == 321,
+            "simulation startup must copy initial M/D values into its runtime repository");
+    require(simulation.executeOnce().succeeded && readBit(repository, 1),
+            "simulation must execute against the copied initial values");
+    simulation.stop();
+    require(!readBit(repository, 1)
+                && readBit(repository, 0)
+                && readWord(repository, 10) == 321,
+            "stopping simulation must restore initial values instead of runtime outputs");
+
+    writeBit(initial_repository, 0, false);
+    require(simulation.start({program}).succeeded,
+            "simulation must support restart with changed initial values");
+    require(!readBit(repository, 0) && !readBit(repository, 1),
+            "restart must use the latest initial values and discard the previous output");
+    simulation.stop();
+}
+
 class FailingVirtualRegisterRepository final : public VirtualRegisterRepository
 {
 public:
@@ -760,6 +791,7 @@ int main(int argc, char *argv[])
         testConflictingCoilsAreRejected();
         testHmiSimulationClosedLoop();
         testSimulationLifecycleSnapshotAndFault();
+        testSimulationUsesInitialValuesAndDiscardsRuntimeOutputs();
         testRepositoryFailureEntersFaultState();
         testOnlineMonitorUsesTemporaryRegistersWithoutWritingPlcSource();
         testOnlineMonitorPreservesFaultAfterStopping();

app/tests/register_monitor_service_tests.cpp

@@ -103,6 +103,33 @@ void testRegisterWrites()
             "monitor word writes must preserve signed 16-bit boundary values");
 }
 
+void testOfflineInitialValueCapture()
+{
+    VirtualRegisterRepository virtual_repository;
+    VirtualRegisterRepository initial_repository;
+    ActiveRegisterRepository active_repository(virtual_repository);
+    RegisterMonitorService service(active_repository);
+    service.setOfflineInitialRepository(initial_repository);
+    service.setOfflineInitialCaptureEnabled(true);
+
+    require(service.writeBit({RegisterArea::M, 3}, true).succeeded
+                && service.writeWord({RegisterArea::D, 10}, -456).succeeded
+                && service.writeFloat({RegisterArea::D, 20}, 1.5f).succeeded,
+            "editing monitor writes must succeed against the virtual repository");
+    require(initial_repository.readBit({RegisterArea::M, 3}).value
+                && initial_repository.readWord({RegisterArea::D, 10}).value == -456
+                && std::fabs(Float32Codec::decode(
+                    initial_repository.readWordPair({RegisterArea::D, 20}).values[0],
+                    initial_repository.readWordPair({RegisterArea::D, 20}).values[1])
+                        .value_or(0.0f) - 1.5f) < 0.000001f,
+            "editing monitor writes must be captured as offline initial values");
+
+    service.setOfflineInitialCaptureEnabled(false);
+    require(service.writeBit({RegisterArea::M, 3}, false).succeeded
+                && initial_repository.readBit({RegisterArea::M, 3}).value,
+            "runtime writes must not overwrite the captured initial values");
+}
+
 void testFloat32Monitoring()
 {
     VirtualRegisterRepository repository;
@@ -151,6 +178,7 @@ int main()
         testRangeManagement();
         testSharedActiveRepositoryValues();
         testRegisterWrites();
+        testOfflineInitialValueCapture();
         testFloat32Monitoring();
     }
     catch (const std::exception &error)