diff --git a/ISCamRecorder/MainForm.cs b/ISCamRecorder/MainForm.cs
index ed59347..5f68adb 100644
--- a/ISCamRecorder/MainForm.cs
+++ b/ISCamRecorder/MainForm.cs
@@ -286,9 +286,15 @@
             _Cameras.ForEach(c => c.StartRecoding());
             _Sensor.StartRecoding(TxtSubjectName.Text);
             _Sounds[0].Play();
+            _Sensor.SendSignal('1'); // Vicon同期信号 on
+            Thread.Sleep(100);
+            _Sensor.SendSignal('0'); // Vicon同期信号 off
 
             // 録画終了待機
             Task.WaitAll(tasks);
+            _Sensor.SendSignal('1'); // Vicon同期信号 on
+            Thread.Sleep(100);
+            _Sensor.SendSignal('0'); // Vicon同期信号 off
 
             // 保存準備
             _Sounds[1].Play();
diff --git a/ISCamRecorder/SensorData.cs b/ISCamRecorder/SensorData.cs
index e1666b9..f5faca7 100644
--- a/ISCamRecorder/SensorData.cs
+++ b/ISCamRecorder/SensorData.cs
@@ -102,8 +102,10 @@
                 if (_Serial != null) {
                     var str = _Serial.ReadLine();
                     var strs = str.Split(',');
-                    if (strs.Length >= 4) {
+                    if (strs.Length == 5) {
                         values = strs.Select(s => int.Parse(s)).ToArray();
+                    } else {
+                        values[0] = values[1] = values[2] = values[3] = 0;
                     }
                 } else {
                     Thread.Sleep(50);   // センサー未接続時の時間調整
@@ -273,6 +275,16 @@
         }
 
         /// <summary>
+        /// シリアルポートに1文字送信
+        /// </summary>
+        /// <param name="c"></param>
+        public void SendSignal(char c) {
+            if (_Serial != null) {
+                _Serial.Write(new char[] { c }, 0, 1);
+            }
+        }
+
+        /// <summary>
         /// シリアルポート取得
         /// </summary>
         /// <returns></returns>
diff --git a/PhotoReflectorIF/PhotoReflectorIF.ino b/PhotoReflectorIF/PhotoReflectorIF.ino
index a3a9a78..e36eec1 100644
--- a/PhotoReflectorIF/PhotoReflectorIF.ino
+++ b/PhotoReflectorIF/PhotoReflectorIF.ino
@@ -67,7 +67,12 @@
   Wire.endTransmission();//I2Cスレーブ データ送信終了
 
   sw = digitalRead(SW_PIN);
-  digitalWrite(SYNC_OUT_PIN, 1 - sw);
+  while (Serial.available() > 0) {
+    char c = Serial.read();
+    if (c == '0') digitalWrite(SYNC_OUT_PIN, 0);
+    if (c == '1') digitalWrite(SYNC_OUT_PIN, 1);
+  }
+  // digitalWrite(SYNC_OUT_PIN, 1 - sw);
 
   Serial.print(blue);//「blue」をシリアルモニタに送信
   Serial.print(",");//文字列「,」をシリアルモニタに送信