Porsche 911 Turbo Owner's Manual page 134

Option 1:
Accepting current speed
f Push operating lever forward.
The acoustic warning signal is activated for the
current speed.
Display:
If the vehicle is stationary, the message "Cannot
be accepted with car stopped" is displayed.
132
Instruments, On-Board Computer, Warnings
Option 2:
Presetting speed
f Select "LIMIT active" with the operating lever:
not active
active
f If "not active", push the operating lever for-
ward.
f Select "xx mph" with the operating lever.
f Push operating lever forward.