AASTRA DT4x2 for MX-ONE User Guide EN - Manual (Page 108)

Settings
DT412/DT422/DT432 108
Automatic key lock
You can set the keypad to lock after 20 seconds after the last
usage. In idle mode a locked keypad is indicated by the Key icon.
When you have entered Settings:
г б
Select General. ã
Select Auto key lock.
Change
Press (see display).
The Auto key lock checkbox is marked/unmarked.
Lock the keypad
The following procedure describes how to manually lock/unlock the
keypad, but it is recommended to always have the automatic lock
on. ç *
Press to lock/unlock the keypad.
The Key icon indicates when your keypad is locked.
Quick answer
When this function is activated, you can answer incoming calls by
simply taking the phone out of the desktop charger. There is no
need to press the Call key.
When you have entered Settings: г б
Select General. ã
Select Quick answer.
Change
Press (see display).
The Quick answer checkbox is marked/unmarked.