AASTRA DT4x2 for BusinessPhone User Guide EN - Manual (Page 87)

87 BusinessPhone – Cordless DT412/DT422/DT432
Alarm
Personal alarm
Activate
Press the red Alarm key twice within 2 seconds.
The display shows
Personal Alarm
and you will hear a short, soft
tone. An alarm is sent to the alarm central. After that, the Cordless
returns to idle mode.
Note: You can always trigger the alarm, even when you are
speaking, editing your settings or while the Cordless is
locked.
Cancel
C Press to cancel the personal alarm (see display).
Test alarm
Press and hold the red Alarm key.
C Press to cancel (see display).