Bticino 342610 Notice De Montage page 52

PROGRAMMING
c) Press the key (7); the display will show four "P"
d) Press again the key (7); the display will show one "n"
followed by the number of currently set call digits (e.g., 4):
e) Dial the new number of call digits, from 1 to 4 (e.g., 2)
f) Confirm the new number of call digits with the key (7),
or cancel with the "C" key (5).
48