diff --git a/app/src/ui/logic_editor_widget.cpp b/app/src/ui/logic_editor_widget.cpp
index 91d58b9..d77f0e7 100644
--- a/app/src/ui/logic_editor_widget.cpp
+++ b/app/src/ui/logic_editor_widget.cpp
@@ -963,7 +963,7 @@ void LogicEditorWidget::reloadLogic()
                 measureExpression(*rung.condition).columns);
         }
     }
-    const int grid_columns = std::max(kMinimumLogicColumns, condition_columns + 2);
+    const int grid_columns = std::max(kMinimumLogicColumns, condition_columns + 1);
     const qreal left_rail_x = kSceneMargin + kRailInset;
     const qreal right_rail_x = left_rail_x + static_cast<qreal>(grid_columns) * kCellWidth;
     const qreal scene_width = std::max(kMinimumSceneWidth, right_rail_x + kSceneMargin);
@@ -1016,7 +1016,7 @@ void LogicEditorWidget::reloadLogic()
             addPlaceholder(
                 *scene_,
                 QRectF(left_rail_x, grid_top, kCellWidth, kCellHeight),
-                tr("添加条件"));
+                rung.output.has_value() ? tr("无条件") : tr("添加条件"));
         }
 
         const bool rung_active = runtime_trace_enabled_ && traceValue(
diff --git a/app/src/ui/logic_instruction_dialog.cpp b/app/src/ui/logic_instruction_dialog.cpp
index 6e950e2..7073f83 100644
--- a/app/src/ui/logic_instruction_dialog.cpp
+++ b/app/src/ui/logic_instruction_dialog.cpp
@@ -165,7 +165,8 @@ void LogicInstructionDialog::updateOperandRanges()
         spin->setPrefix(register_operand ? QStringLiteral("D") : QString{});
         spin->setMinimum(register_operand
             ? RegisterAddress::kMinimumIndex
-            : std::numeric_limits<std::int16_t>::min());
+            : (combo->objectName() == QStringLiteral("counterPresetKindComboBox")
+                   ? 0 : std::numeric_limits<std::int16_t>::min()));
         spin->setMaximum(register_operand
             ? RegisterAddress::kMaximumIndex
             : std::numeric_limits<std::int16_t>::max());
diff --git a/app/src/ui/main_window.cpp b/app/src/ui/main_window.cpp
index 30590c8..042e816 100644
--- a/app/src/ui/main_window.cpp
+++ b/app/src/ui/main_window.cpp
@@ -23,6 +23,8 @@
 #include "services/register_comment_service.h"
 #include "ui_main_window.h"
 
+#include "domain/project_limits.h"
+
 #include <QActionGroup>
 #include <QAbstractSpinBox>
 #include <QApplication>
@@ -851,8 +853,7 @@ void MainWindow::configureRuntimeMonitor()
         },
         [this](const QString &message)
         {
-            ui_->outputList->addItem(message);
-            ui_->outputList->scrollToBottom();
+            appendOutputMessage(message);
         });
     runtime_panel_controller_->configure();
     runtime_monitor_widget_ = runtime_panel_controller_->runtimeMonitorWidget();
@@ -1467,14 +1468,23 @@ void MainWindow::showProjectResult(
 {
     const QString output = action + QStringLiteral(": ") + message;
     statusBar()->showMessage(output, 5000);
-    ui_->outputList->addItem(output);
-    ui_->outputList->scrollToBottom();
+    appendOutputMessage(output);
     if (!succeeded)
     {
         QMessageBox::warning(this, action, message);
     }
 }
 
+void MainWindow::appendOutputMessage(const QString &message)
+{
+    while (ui_->outputList->count() >= ProjectLimits::kMaximumOutputMessages)
+    {
+        delete ui_->outputList->takeItem(0);
+    }
+    ui_->outputList->addItem(message);
+    ui_->outputList->scrollToBottom();
+}
+
 void MainWindow::requestMode(ApplicationMode requested_mode)
 {
     // UI 仅转发模式意图，合法性由服务层和领域状态机决定
@@ -1662,8 +1672,7 @@ void MainWindow::updateModeUi(const QString &message)
         && ui_->outputList->item(ui_->outputList->count() - 1)->text() == message;
     if (!duplicate)
     {
-        ui_->outputList->addItem(message);
-        ui_->outputList->scrollToBottom();
+        appendOutputMessage(message);
     }
 }
 
diff --git a/app/src/ui/main_window.h b/app/src/ui/main_window.h
index a44c608..611e5d3 100644
--- a/app/src/ui/main_window.h
+++ b/app/src/ui/main_window.h
@@ -162,6 +162,7 @@ private:
     void loadProject();
     // 在状态栏和输出面板显示工程操作结果
     void showProjectResult(const QString &action, const QString &message, bool succeeded);
+    void appendOutputMessage(const QString &message);
 
     /**
      * @brief 请求服务层切换模式并同步界面状态
diff --git a/app/src/ui/main_window.ui b/app/src/ui/main_window.ui
index 4e92146..0eb60d0 100644
--- a/app/src/ui/main_window.ui
+++ b/app/src/ui/main_window.ui
@@ -498,7 +498,7 @@
              <item row="2" column="1">
               <widget class="QSpinBox" name="controlXSpinBox">
                <property name="maximum">
-                <number>4000</number>
+                <number>8192</number>
                </property>
               </widget>
              </item>
@@ -512,7 +512,7 @@
              <item row="3" column="1">
               <widget class="QSpinBox" name="controlYSpinBox">
                <property name="maximum">
-                <number>4000</number>
+                <number>8192</number>
                </property>
               </widget>
              </item>
@@ -529,7 +529,7 @@
                 <number>1</number>
                </property>
                <property name="maximum">
-                <number>4000</number>
+                <number>8192</number>
                </property>
               </widget>
              </item>
@@ -546,7 +546,7 @@
                 <number>1</number>
                </property>
                <property name="maximum">
-                <number>4000</number>
+                <number>8192</number>
                </property>
               </widget>
              </item>
diff --git a/app/src/ui/plc_connection_dialog.ui b/app/src/ui/plc_connection_dialog.ui
index 0396983..4fddecd 100644
--- a/app/src/ui/plc_connection_dialog.ui
+++ b/app/src/ui/plc_connection_dialog.ui
@@ -65,7 +65,7 @@
       <item row="0" column="0"><widget class="QLabel" name="responseTimeoutLabel"><property name="text"><string>响应超时</string></property></widget></item>
       <item row="0" column="1"><widget class="QSpinBox" name="responseTimeoutSpinBox"><property name="suffix"><string> ms</string></property><property name="minimum"><number>100</number></property><property name="maximum"><number>30000</number></property><property name="singleStep"><number>100</number></property><property name="value"><number>1000</number></property></widget></item>
       <item row="1" column="0"><widget class="QLabel" name="retriesLabel"><property name="text"><string>失败重试</string></property></widget></item>
-      <item row="1" column="1"><widget class="QSpinBox" name="retriesSpinBox"><property name="suffix"><string> 次</string></property><property name="maximum"><number>10</number></property><property name="value"><number>2</number></property></widget></item>
+      <item row="1" column="1"><widget class="QSpinBox" name="retriesSpinBox"><property name="suffix"><string> 次</string></property><property name="maximum"><number>5</number></property><property name="value"><number>2</number></property></widget></item>
       <item row="2" column="0"><widget class="QLabel" name="pollIntervalLabel"><property name="text"><string>轮询周期</string></property></widget></item>
       <item row="2" column="1"><widget class="QSpinBox" name="pollIntervalSpinBox"><property name="suffix"><string> ms</string></property><property name="minimum"><number>50</number></property><property name="maximum"><number>10000</number></property><property name="singleStep"><number>50</number></property><property name="value"><number>200</number></property></widget></item>
      </layout>
diff --git a/app/tests/main_window_tests.cpp b/app/tests/main_window_tests.cpp
index 364db30..7c79a8e 100644
--- a/app/tests/main_window_tests.cpp
+++ b/app/tests/main_window_tests.cpp
@@ -84,7 +84,11 @@ public:
         notifyStateChanged();
     }
 
-    void setPollAddresses(const std::vector<RegisterAddress> &) override {}
+    PlcCommunicationResult setPollAddresses(
+        const std::vector<RegisterAddress> &) override
+    {
+        return {true, {}};
+    }
     PlcConnectionState state() const override { return connection_state; }
     bool initialReadCompleted() const override { return false; }
     PlcCommunicationError lastErrorType() const override
@@ -149,9 +153,11 @@ public:
         }
     }
 
-    void setPollAddresses(const std::vector<RegisterAddress> &addresses) override
+    PlcCommunicationResult setPollAddresses(
+        const std::vector<RegisterAddress> &addresses) override
     {
         poll_addresses = addresses;
+        return {true, {}};
     }
 
     PlcConnectionState state() const override { return connection_state; }