Leica GPS1200+ Technical Reference Manual page 124

Receiver Protection with PIN
Next step
IF the PUK code
entered is
correct
wrong
THEN
the old PIN code is cleared and the PIN protection is deactivated.
GPS1200+ Main Menu is displayed. Refer to "7 Main Menu".
GPS1200+ keeps asking for the correct PUK code.
SHIFT QUIT (F6) to turn off the receiver.
GPS1200+ 124