添加读取监控

app/src/main/java/com/example/pdaplccontrol/MainActivity.java

@@ -1,11 +1,15 @@
 package com.example.pdaplccontrol;
 
+import android.content.res.ColorStateList;
 import android.os.Bundle;
+import android.os.Handler;
+import android.os.Looper;
 import android.view.KeyEvent;
 import android.view.View;
 import android.view.inputmethod.EditorInfo;
 import android.widget.Button;
 import android.widget.EditText;
+import android.widget.LinearLayout;
 import android.widget.TextView;
 import android.widget.Toast;
 
@@ -14,18 +18,45 @@ import androidx.appcompat.app.AppCompatActivity;
 public class MainActivity extends AppCompatActivity implements View.OnClickListener {
 
     private final Button[] lineButtons = new Button[9];
+    private final Handler monitorHandler = new Handler(Looper.getMainLooper());
+    private final Runnable monitorRunnable = new Runnable() {
+        @Override
+        public void run() {
+            readCurrentValues();
+        }
+    };
     private EditText editWeightKg;
+    private TextView textMonitorStatus;
+    private LinearLayout rootLayout;
+    private boolean monitorRunning;
+    private boolean monitorRequestInFlight;
+    private ColorStateList defaultLineButtonBackgroundTint;
+    private ColorStateList defaultLineButtonTextColors;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
 
+        rootLayout = findViewById(R.id.rootLayout);
         editWeightKg = findViewById(R.id.editWeightKg);
+        textMonitorStatus = findViewById(R.id.textMonitorStatus);
         setupWeightInput();
         setupLineButtons();
     }
 
+    @Override
+    protected void onStart() {
+        super.onStart();
+        startMonitor();
+    }
+
+    @Override
+    protected void onStop() {
+        stopMonitor();
+        super.onStop();
+    }
+
     private void setupWeightInput() {
         editWeightKg.setOnEditorActionListener(new TextView.OnEditorActionListener() {
             @Override
@@ -35,6 +66,7 @@ public class MainActivity extends AppCompatActivity implements View.OnClickListe
                         && event.getAction() == KeyEvent.ACTION_UP
                         && event.getKeyCode() == KeyEvent.KEYCODE_ENTER);
                 if (isDone) {
+                    rootLayout.requestFocus();
                     sendWeight();
                     return true;
                 }
@@ -58,6 +90,8 @@ public class MainActivity extends AppCompatActivity implements View.OnClickListe
             lineButtons[i].setTag((short) (PlcConfig.MIN_LINE_NUMBER + i));
             lineButtons[i].setOnClickListener(this);
         }
+        defaultLineButtonBackgroundTint = lineButtons[0].getBackgroundTintList();
+        defaultLineButtonTextColors = lineButtons[0].getTextColors();
     }
 
     @Override
@@ -73,18 +107,19 @@ public class MainActivity extends AppCompatActivity implements View.OnClickListe
     }
 
     private void sendWeight() {
-        final short weightGrams;
+        final short weightKg;
         try {
-            weightGrams = WeightInputParser.kgToGrams(editWeightKg.getText().toString());
+            weightKg = WeightInputParser.parseKg(editWeightKg.getText().toString());
         } catch (IllegalArgumentException e) {
             Toast.makeText(this, e.getMessage(), Toast.LENGTH_LONG).show();
             return;
         }
 
         setControlsEnabled(false);
-        Toast.makeText(this, "正在向 PLC 发送重量 " + weightGrams + "g...", Toast.LENGTH_SHORT).show();
+        Toast.makeText(this, "正在向 PLC 发送重量 "
+                + WeightInputParser.kgToDisplayText(weightKg) + "kg...", Toast.LENGTH_SHORT).show();
 
-        PlcManager.getInstance().sendWeightGramsAsync(weightGrams, createCallback());
+        PlcManager.getInstance().sendWeightKgAsync(weightKg, createCallback());
     }
 
     private PlcManager.PlcCallback createCallback() {
@@ -111,4 +146,99 @@ public class MainActivity extends AppCompatActivity implements View.OnClickListe
             }
         }
     }
+
+    private void startMonitor() {
+        monitorRunning = true;
+        monitorHandler.removeCallbacks(monitorRunnable);
+        renderMonitorPending();
+        monitorHandler.post(monitorRunnable);
+    }
+
+    private void stopMonitor() {
+        monitorRunning = false;
+        monitorHandler.removeCallbacks(monitorRunnable);
+    }
+
+    private void readCurrentValues() {
+        if (!monitorRunning || monitorRequestInFlight) {
+            return;
+        }
+
+        monitorRequestInFlight = true;
+        PlcManager.getInstance().readCurrentValuesAsync(new PlcManager.PlcCurrentValuesCallback() {
+            @Override
+            public void onSuccess(PlcCurrentValues values) {
+                monitorRequestInFlight = false;
+                if (monitorRunning) {
+                    renderCurrentValues(values);
+                }
+                scheduleNextMonitorRead();
+            }
+
+            @Override
+            public void onError(String error) {
+                monitorRequestInFlight = false;
+                if (monitorRunning) {
+                    renderMonitorStale();
+                }
+                scheduleNextMonitorRead();
+            }
+        });
+    }
+
+    private void scheduleNextMonitorRead() {
+        if (monitorRunning) {
+            monitorHandler.postDelayed(monitorRunnable, PlcConfig.MONITOR_INTERVAL_MILLIS);
+        }
+    }
+
+    private void renderCurrentValues(PlcCurrentValues values) {
+        renderMonitorNormal();
+        if (!editWeightKg.hasFocus()) {
+            editWeightKg.setText(WeightInputParser.kgToDisplayText(values.getWeightKg()));
+        }
+        renderCurrentLineNumber(values.getLineNumber());
+    }
+
+    private void renderMonitorPending() {
+        textMonitorStatus.setText("正在读取PLC...");
+        textMonitorStatus.setTextColor(getColor(R.color.monitor_status_pending));
+    }
+
+    private void renderMonitorNormal() {
+        textMonitorStatus.setText("监控正常");
+        textMonitorStatus.setTextColor(getColor(R.color.monitor_status_normal));
+    }
+
+    private void renderMonitorStale() {
+        textMonitorStatus.setText("已失联/数据过期");
+        textMonitorStatus.setTextColor(getColor(R.color.monitor_status_stale));
+        clearCurrentLineNumberHighlight();
+    }
+
+    private void renderCurrentLineNumber(short currentLineNumber) {
+        for (Button btn : lineButtons) {
+            if (btn == null) {
+                continue;
+            }
+
+            short buttonLineNumber = (short) btn.getTag();
+            if (buttonLineNumber == currentLineNumber) {
+                btn.setBackgroundTintList(ColorStateList.valueOf(getColor(R.color.line_monitor_active)));
+                btn.setTextColor(getColor(R.color.line_monitor_active_text));
+            } else {
+                btn.setBackgroundTintList(defaultLineButtonBackgroundTint);
+                btn.setTextColor(defaultLineButtonTextColors);
+            }
+        }
+    }
+
+    private void clearCurrentLineNumberHighlight() {
+        for (Button btn : lineButtons) {
+            if (btn != null) {
+                btn.setBackgroundTintList(defaultLineButtonBackgroundTint);
+                btn.setTextColor(defaultLineButtonTextColors);
+            }
+        }
+    }
 }

app/src/main/java/com/example/pdaplccontrol/Moka7PlcValueSender.java

@@ -11,18 +11,23 @@ class Moka7PlcValueSender implements PlcValueSender {
     }
 
     @Override
-    public void sendWeightGrams(short weightGrams) throws PlcCommunicationException {
-        writeWord(PlcConfig.WEIGHT_GRAMS_OFFSET, weightGrams);
+    public void sendWeightKg(short weightKg) throws PlcCommunicationException {
+        writeWord(PlcConfig.WEIGHT_KG_OFFSET, weightKg);
+    }
+
+    @Override
+    public PlcCurrentValues readCurrentValues() throws PlcCommunicationException {
+        byte[] data = readBytes(PlcConfig.MONITOR_START_OFFSET, PlcConfig.MONITOR_BYTE_LENGTH);
+        return new PlcCurrentValues(
+                decodeWord(data, PlcConfig.LINE_NUMBER_OFFSET - PlcConfig.MONITOR_START_OFFSET),
+                decodeWord(data, PlcConfig.WEIGHT_KG_OFFSET - PlcConfig.MONITOR_START_OFFSET)
+        );
     }
 
     private void writeWord(int offset, short value) throws PlcCommunicationException {
         S7Client client = new S7Client();
         try {
-            client.SetConnectionType(S7.OP);
-            int connectRes = client.ConnectTo(PlcConfig.PLC_IP, PlcConfig.RACK, PlcConfig.SLOT);
-            if (connectRes != 0) {
-                throw new PlcCommunicationException("PLC连接失败，错误码：" + connectRes);
-            }
+            connect(client);
 
             int writeRes = client.WriteArea(
                     S7.S7AreaDB,
@@ -43,10 +48,42 @@ class Moka7PlcValueSender implements PlcValueSender {
         }
     }
 
+    private byte[] readBytes(int offset, int amount) throws PlcCommunicationException {
+        S7Client client = new S7Client();
+        try {
+            connect(client);
+
+            byte[] data = new byte[amount];
+            int readRes = client.ReadArea(S7.S7AreaDB, PlcConfig.DB_NUMBER, offset, amount, data);
+            if (readRes != 0) {
+                throw new PlcCommunicationException("读取数据失败，错误码：" + S7Client.ErrorText(readRes));
+            }
+            return data;
+        } catch (PlcCommunicationException e) {
+            throw e;
+        } catch (Exception e) {
+            throw new PlcCommunicationException("通讯发生异常: " + e.getMessage(), e);
+        } finally {
+            client.Disconnect();
+        }
+    }
+
+    private void connect(S7Client client) throws PlcCommunicationException {
+        client.SetConnectionType(S7.OP);
+        int connectRes = client.ConnectTo(PlcConfig.PLC_IP, PlcConfig.RACK, PlcConfig.SLOT);
+        if (connectRes != 0) {
+            throw new PlcCommunicationException("PLC连接失败，错误码：" + connectRes);
+        }
+    }
+
     static byte[] encodeWord(short value) {
         byte[] data = new byte[PlcConfig.WORD_BYTE_LENGTH];
         // S7 的 Word/Int 都是 2 字节大端格式；当前值范围都在正数区间内。
         S7.SetShortAt(data, 0, value);
         return data;
     }
+
+    static short decodeWord(byte[] data, int offset) {
+        return (short) S7.GetShortAt(data, offset);
+    }
 }

app/src/main/java/com/example/pdaplccontrol/PlcConfig.java

@@ -8,12 +8,15 @@ final class PlcConfig {
     static final int SLOT = 1;
     static final int DB_NUMBER = 49;
     static final int LINE_NUMBER_OFFSET = 32;
-    static final int WEIGHT_GRAMS_OFFSET = 34;
+    static final int WEIGHT_KG_OFFSET = 34;
     static final int WORD_BYTE_LENGTH = 2;
+    static final int MONITOR_START_OFFSET = LINE_NUMBER_OFFSET;
+    static final int MONITOR_BYTE_LENGTH = WEIGHT_KG_OFFSET + WORD_BYTE_LENGTH - MONITOR_START_OFFSET;
+    static final int MONITOR_INTERVAL_MILLIS = 2000;
     static final int MIN_LINE_NUMBER = 10;
     static final int MAX_LINE_NUMBER = 18;
-    static final int MIN_WEIGHT_GRAMS = 0;
-    static final int MAX_WEIGHT_GRAMS = 30000;
+    static final int MIN_WEIGHT_KG = 0;
+    static final int MAX_WEIGHT_KG = 30;
 
     private PlcConfig() {
     }

app/src/main/java/com/example/pdaplccontrol/PlcCurrentValues.java

@@ -0,0 +1,20 @@
+package com.example.pdaplccontrol;
+
+final class PlcCurrentValues {
+
+    private final short lineNumber;
+    private final short weightKg;
+
+    PlcCurrentValues(short lineNumber, short weightKg) {
+        this.lineNumber = lineNumber;
+        this.weightKg = weightKg;
+    }
+
+    short getLineNumber() {
+        return lineNumber;
+    }
+
+    short getWeightKg() {
+        return weightKg;
+    }
+}

app/src/main/java/com/example/pdaplccontrol/PlcManager.java

@@ -35,6 +35,11 @@ public class PlcManager {
         void onError(String error);
     }
 
+    public interface PlcCurrentValuesCallback {
+        void onSuccess(PlcCurrentValues values);
+        void onError(String error);
+    }
+
     public void sendLineNumberAsync(final short lineNumber, final PlcCallback callback) {
         if (!isValidLineNumber(lineNumber)) {
             notifyError(callback, "线体号无效，只允许 10-18");
@@ -54,8 +59,8 @@ public class PlcManager {
         });
     }
 
-    public void sendWeightGramsAsync(final short weightGrams, final PlcCallback callback) {
-        if (!isValidWeightGrams(weightGrams)) {
+    public void sendWeightKgAsync(final short weightKg, final PlcCallback callback) {
+        if (!isValidWeightKg(weightKg)) {
             notifyError(callback, "重量范围为 0-30kg");
             return;
         }
@@ -64,8 +69,9 @@ public class PlcManager {
             @Override
             public void run() {
                 try {
-                    plcValueSender.sendWeightGrams(weightGrams);
-                    notifySuccess(callback, "成功下发重量: " + weightGrams + "g");
+                    plcValueSender.sendWeightKg(weightKg);
+                    notifySuccess(callback, "成功下发重量: "
+                            + WeightInputParser.kgToDisplayText(weightKg) + "kg");
                 } catch (PlcCommunicationException e) {
                     notifyError(callback, e.getMessage());
                 }
@@ -73,12 +79,26 @@ public class PlcManager {
         });
     }
 
+    public void readCurrentValuesAsync(final PlcCurrentValuesCallback callback) {
+        commandExecutor.execute(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    notifyCurrentValuesSuccess(callback, plcValueSender.readCurrentValues());
+                } catch (PlcCommunicationException e) {
+                    notifyCurrentValuesError(callback, e.getMessage());
+                }
+            }
+        });
+    }
+
     static boolean isValidLineNumber(short lineNumber) {
         return lineNumber >= PlcConfig.MIN_LINE_NUMBER && lineNumber <= PlcConfig.MAX_LINE_NUMBER;
     }
 
-    static boolean isValidWeightGrams(short weightGrams) {
-        return weightGrams >= PlcConfig.MIN_WEIGHT_GRAMS && weightGrams <= PlcConfig.MAX_WEIGHT_GRAMS;
+    static boolean isValidWeightKg(short weightKg) {
+        return weightKg >= PlcConfig.MIN_WEIGHT_KG
+                && weightKg <= PlcConfig.MAX_WEIGHT_KG;
     }
 
     private void notifySuccess(final PlcCallback callback, final String message) {
@@ -103,6 +123,31 @@ public class PlcManager {
         });
     }
 
+    private void notifyCurrentValuesSuccess(
+            final PlcCurrentValuesCallback callback,
+            final PlcCurrentValues values
+    ) {
+        callbackExecutor.execute(new Runnable() {
+            @Override
+            public void run() {
+                if (callback != null) {
+                    callback.onSuccess(values);
+                }
+            }
+        });
+    }
+
+    private void notifyCurrentValuesError(final PlcCurrentValuesCallback callback, final String error) {
+        callbackExecutor.execute(new Runnable() {
+            @Override
+            public void run() {
+                if (callback != null) {
+                    callback.onError(error);
+                }
+            }
+        });
+    }
+
     private static class MainThreadExecutor implements Executor {
         private final Handler mainHandler = new Handler(Looper.getMainLooper());
 

app/src/main/java/com/example/pdaplccontrol/PlcValueSender.java

@@ -8,7 +8,12 @@ public interface PlcValueSender {
     void sendLineNumber(short lineNumber) throws PlcCommunicationException;
 
     /**
-     * 只在用户完成重量输入时写一次；PLC 侧按克整数保存重量。
+     * 只在用户完成重量输入时写一次；PLC 侧按 kg 整数保存重量。
      */
-    void sendWeightGrams(short weightGrams) throws PlcCommunicationException;
+    void sendWeightKg(short weightKg) throws PlcCommunicationException;
+
+    /**
+     * 周期读取 PLC 当前值，用于界面监控显示。
+     */
+    PlcCurrentValues readCurrentValues() throws PlcCommunicationException;
 }

app/src/main/java/com/example/pdaplccontrol/WeightInputParser.java

@@ -1,36 +1,30 @@
 package com.example.pdaplccontrol;
 
-import java.math.BigDecimal;
-
 final class WeightInputParser {
 
-    private static final BigDecimal GRAMS_PER_KG = new BigDecimal("1000");
-
     private WeightInputParser() {
     }
 
-    static short kgToGrams(String input) {
+    static short parseKg(String input) {
         if (input == null || input.trim().isEmpty()) {
             throw new IllegalArgumentException("请输入重量");
         }
 
-        BigDecimal kg;
+        int kg;
         try {
-            kg = new BigDecimal(input.trim());
+            kg = Integer.parseInt(input.trim());
         } catch (NumberFormatException e) {
-            throw new IllegalArgumentException("重量格式不正确");
+            throw new IllegalArgumentException("重量必须为整数kg");
         }
 
-        BigDecimal grams = kg.movePointRight(3).stripTrailingZeros();
-        if (kg.compareTo(BigDecimal.ZERO) < 0
-                || grams.compareTo(BigDecimal.valueOf(PlcConfig.MAX_WEIGHT_GRAMS)) > 0) {
+        if (kg < PlcConfig.MIN_WEIGHT_KG || kg > PlcConfig.MAX_WEIGHT_KG) {
             throw new IllegalArgumentException("重量范围为 0-30kg");
         }
 
-        try {
-            return grams.shortValueExact();
-        } catch (ArithmeticException e) {
-            throw new IllegalArgumentException("重量最多精确到 0.001kg");
-        }
+        return (short) kg;
+    }
+
+    static String kgToDisplayText(short weightKg) {
+        return String.valueOf(weightKg);
     }
 }

app/src/main/res/layout/activity_main.xml

@@ -1,11 +1,23 @@
 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/rootLayout"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:focusable="true"
+    android:focusableInTouchMode="true"
     android:gravity="center"
     android:orientation="vertical"
     android:padding="16dp">
 
+    <TextView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="24dp"
+        android:gravity="center"
+        android:text="西线重投工位产品信息输入"
+        android:textSize="26sp"
+        android:textStyle="bold" />
+
     <TextView
         android:layout_width="220dp"
         android:layout_height="wrap_content"
@@ -19,13 +31,23 @@
         android:id="@+id/editWeightKg"
         android:layout_width="220dp"
         android:layout_height="wrap_content"
-        android:layout_marginBottom="24dp"
-        android:hint="0.000"
+        android:layout_marginBottom="8dp"
+        android:hint="0"
         android:imeOptions="actionDone"
-        android:inputType="numberDecimal"
+        android:inputType="number"
         android:singleLine="true"
         android:textSize="20sp" />
 
+    <TextView
+        android:id="@+id/textMonitorStatus"
+        android:layout_width="220dp"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="24dp"
+        android:gravity="center"
+        android:text="正在读取PLC..."
+        android:textColor="@color/monitor_status_pending"
+        android:textSize="16sp" />
+
     <TextView
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"

app/src/main/res/values/colors.xml

@@ -2,4 +2,9 @@
 <resources>
     <color name="black">#FF000000</color>
     <color name="white">#FFFFFFFF</color>
-</resources>
+    <color name="line_monitor_active">#2E7D32</color>
+    <color name="line_monitor_active_text">#FFFFFFFF</color>
+    <color name="monitor_status_normal">#2E7D32</color>
+    <color name="monitor_status_stale">#C62828</color>
+    <color name="monitor_status_pending">#616161</color>
+</resources>

app/src/test/java/com/example/pdaplccontrol/ExampleUnitTest.java

@@ -20,25 +20,32 @@ public class ExampleUnitTest {
     }
 
     @Test
-    public void kgToGrams_acceptsZeroToThirtyKgWithGramPrecision() {
-        assertEquals(0, WeightInputParser.kgToGrams("0"));
-        assertEquals(1000, WeightInputParser.kgToGrams("1"));
-        assertEquals(12345, WeightInputParser.kgToGrams("12.345"));
-        assertEquals(30000, WeightInputParser.kgToGrams("30"));
+    public void parseKg_acceptsZeroToThirtyIntegerKg() {
+        assertEquals(0, WeightInputParser.parseKg("0"));
+        assertEquals(1, WeightInputParser.parseKg("1"));
+        assertEquals(12, WeightInputParser.parseKg("12"));
+        assertEquals(30, WeightInputParser.parseKg("30"));
     }
 
     @Test
-    public void kgToGrams_rejectsInvalidInput() {
+    public void parseKg_rejectsInvalidInput() {
         assertInvalidWeight("");
         assertInvalidWeight("abc");
-        assertInvalidWeight("-0.001");
-        assertInvalidWeight("30.001");
-        assertInvalidWeight("1.2345");
+        assertInvalidWeight("-1");
+        assertInvalidWeight("31");
+        assertInvalidWeight("1.12");
+    }
+
+    @Test
+    public void kgToDisplayText_showsIntegerKg() {
+        assertEquals("0", WeightInputParser.kgToDisplayText((short) 0));
+        assertEquals("1", WeightInputParser.kgToDisplayText((short) 1));
+        assertEquals("12", WeightInputParser.kgToDisplayText((short) 12));
     }
 
     private void assertInvalidWeight(String input) {
         try {
-            WeightInputParser.kgToGrams(input);
+            WeightInputParser.parseKg(input);
             fail("Expected invalid weight for input: " + input);
         } catch (IllegalArgumentException expected) {
             // 测试只关心非法输入会被拦截，具体提示由业务层统一维护。

app/src/test/java/com/example/pdaplccontrol/Moka7PlcValueSenderTest.java

@@ -19,4 +19,12 @@ public class Moka7PlcValueSenderTest {
             assertEquals(value, (short) S7.GetShortAt(data, 0));
         }
     }
+
+    @Test
+    public void decodeWord_validPositiveValues_readsS7BigEndianBytes() {
+        short value = 12;
+        byte[] data = Moka7PlcValueSender.encodeWord(value);
+
+        assertEquals(value, Moka7PlcValueSender.decodeWord(data, 0));
+    }
 }

app/src/test/java/com/example/pdaplccontrol/PlcManagerTest.java

@@ -19,7 +19,7 @@ public class PlcManagerTest {
 
             assertNotNull(sender.lineNumber);
             assertEquals((int) lineNumber, (int) sender.lineNumber);
-            assertNull(sender.weightGrams);
+            assertNull(sender.weightKg);
             assertEquals("成功下发线体号: " + lineNumber, callback.successMessage);
             assertNull(callback.errorMessage);
         }
@@ -34,39 +34,54 @@ public class PlcManagerTest {
         manager.sendLineNumberAsync((short) 9, callback);
 
         assertNull(sender.lineNumber);
-        assertNull(sender.weightGrams);
+        assertNull(sender.weightKg);
         assertNull(callback.successMessage);
         assertEquals("线体号无效，只允许 10-18", callback.errorMessage);
     }
 
     @Test
-    public void sendWeightGramsAsync_validWeight_delegatesExactGrams() {
+    public void sendWeightKgAsync_validWeight_delegatesExactKg() {
         RecordingPlcValueSender sender = new RecordingPlcValueSender();
         RecordingCallback callback = new RecordingCallback();
         PlcManager manager = new PlcManager(sender, new DirectExecutor(), new DirectExecutor());
 
-        manager.sendWeightGramsAsync((short) 12345, callback);
+        manager.sendWeightKgAsync((short) 12, callback);
 
         assertNull(sender.lineNumber);
-        assertEquals(12345, (int) sender.weightGrams);
-        assertEquals("成功下发重量: 12345g", callback.successMessage);
+        assertEquals(12, (int) sender.weightKg);
+        assertEquals("成功下发重量: 12kg", callback.successMessage);
         assertNull(callback.errorMessage);
     }
 
     @Test
-    public void sendWeightGramsAsync_invalidWeight_doesNotCallSender() {
+    public void sendWeightKgAsync_invalidWeight_doesNotCallSender() {
         RecordingPlcValueSender sender = new RecordingPlcValueSender();
         RecordingCallback callback = new RecordingCallback();
         PlcManager manager = new PlcManager(sender, new DirectExecutor(), new DirectExecutor());
 
-        manager.sendWeightGramsAsync((short) -1, callback);
+        manager.sendWeightKgAsync((short) -1, callback);
 
         assertNull(sender.lineNumber);
-        assertNull(sender.weightGrams);
+        assertNull(sender.weightKg);
         assertNull(callback.successMessage);
         assertEquals("重量范围为 0-30kg", callback.errorMessage);
     }
 
+    @Test
+    public void readCurrentValuesAsync_delegatesCurrentValues() {
+        RecordingPlcValueSender sender = new RecordingPlcValueSender();
+        sender.currentValues = new PlcCurrentValues((short) 11, (short) 12);
+        RecordingCurrentValuesCallback callback = new RecordingCurrentValuesCallback();
+        PlcManager manager = new PlcManager(sender, new DirectExecutor(), new DirectExecutor());
+
+        manager.readCurrentValuesAsync(callback);
+
+        assertNotNull(callback.values);
+        assertEquals(11, callback.values.getLineNumber());
+        assertEquals(12, callback.values.getWeightKg());
+        assertNull(callback.errorMessage);
+    }
+
     private static class DirectExecutor implements Executor {
         @Override
         public void execute(Runnable command) {
@@ -76,7 +91,8 @@ public class PlcManagerTest {
 
     private static class RecordingPlcValueSender implements PlcValueSender {
         private Short lineNumber;
-        private Short weightGrams;
+        private Short weightKg;
+        private PlcCurrentValues currentValues = new PlcCurrentValues((short) 10, (short) 0);
 
         @Override
         public void sendLineNumber(short lineNumber) {
@@ -84,8 +100,13 @@ public class PlcManagerTest {
         }
 
         @Override
-        public void sendWeightGrams(short weightGrams) {
-            this.weightGrams = weightGrams;
+        public void sendWeightKg(short weightKg) {
+            this.weightKg = weightKg;
+        }
+
+        @Override
+        public PlcCurrentValues readCurrentValues() {
+            return currentValues;
         }
     }
 
@@ -103,4 +124,19 @@ public class PlcManagerTest {
             errorMessage = error;
         }
     }
+
+    private static class RecordingCurrentValuesCallback implements PlcManager.PlcCurrentValuesCallback {
+        private PlcCurrentValues values;
+        private String errorMessage;
+
+        @Override
+        public void onSuccess(PlcCurrentValues values) {
+            this.values = values;
+        }
+
+        @Override
+        public void onError(String error) {
+            errorMessage = error;
+        }
+    }
 }