diff --git a/app/src/main/java/com/xypower/mpapp/MainActivity.java b/app/src/main/java/com/xypower/mpapp/MainActivity.java
index 07078d68..99ea14fc 100644
--- a/app/src/main/java/com/xypower/mpapp/MainActivity.java
+++ b/app/src/main/java/com/xypower/mpapp/MainActivity.java
@@ -228,6 +228,10 @@ public class MainActivity extends AppCompatActivity {
                 Context appContext = getApplicationContext();
                 MicroPhotoContext.AppConfig curAppConfig = MicroPhotoContext.getMpAppConfig(appContext);
 
+                if (TextUtils.isEmpty(curAppConfig.cmdid)) {
+                    curAppConfig.cmdid = MicroPhotoService.getSerialNumber();
+                }
+
                 startMicroPhotoService(appContext, curAppConfig, mMessenger);
 
                 binding.btnStartServ.setEnabled(false);