diff --git a/app/app.c b/app/app.c
index 28f79a5..0f4c30f 100644
--- a/app/app.c
+++ b/app/app.c
@@ -1586,12 +1586,19 @@ void APP_TimeSlice500ms(void)
         gWakeUp = false;
     }
 
-    if (gSleepModeCountdown_500ms > 0 && --gSleepModeCountdown_500ms == 0) {
-        gBacklightCountdown_500ms = 0;
-        BACKLIGHT_TurnOff();
-        ST7565_ShutDown();
-        gPowerSave_10ms = 1;
-        gWakeUp = true;
+    if(gCurrentFunction != FUNCTION_TRANSMIT && !FUNCTION_IsRx())
+    {
+        if (gSleepModeCountdown_500ms > 0 && --gSleepModeCountdown_500ms == 0) {
+            gBacklightCountdown_500ms = 0;
+            BACKLIGHT_TurnOff();
+            ST7565_ShutDown();
+            gPowerSave_10ms = 1;
+            gWakeUp = true;
+        }
+    }
+    else
+    {
+        gSleepModeCountdown_500ms = gSetting_set_off * 120;
     }
 
     if (gWakeUp) {