10.17.3.7. Activate/deactivate COS changeover from the terminal 
Input of the activation code (from WABE ACOSX e.g. *18) followed by
COSXCD (as added in AMO PERSI e.g.1234) on the terminal. After the changeover,
a special dial tone should be injected instead of the normal one, when
the handset is lifted.
Enter the deactivation code to unlock the respective keys or functions:
Enter the deactivation code (e.g. #18) on the terminal. After the
COS changeover the normal dialing tone is injected when the handset is
lifted.
Delete the protective parameters for the station to unlock the keys
after a COS changeover: