Preliminary remarks: Several types of action are possible on each key of the keypad, depending on
whether the user presses the key briefly (short press, < 2s, validated by a beep) or at length (long
press, > 2s, validated by a beep having a tone different from that of the beep emitted for a short press).
In what follows, these different actions are symbolized as follows :
for a short press on the key in question.
2
5
5
2. DESCRIPTION
for a press > 2s on the key in question.
5
44
3
4
1
5
6