ECOTEST DKG-21 M Operating Manual page 80

Press shortly the MODE button to switch the alarm
clock on/off after setting the time of its triggering. A
blinking sound symbol ")))" should appear on the LCD.
Press shortly the THRESHOLD button; make the non
blinking sound symbol appear on the LCD to switch the
alarm clock on.
Press shortly the THRESHOLD button to switch the
alarm clock off. The sound symbol should extinct. Fix
the alarm clock settings by further short pressing of the
MODE button. If the alarm clock is on, the sound
symbol will be displayed on the LCD irrespective of the
selected operating mode.
79