Panasonic KX-NCP500 User Manual page 37

To answer the callback ringing from an idle outside line
PT/SLT/PS
While hearing a callback ringing
Off-hook.
•
If you do not answer the callback ringing within 10 seconds, this feature will be cancelled.
To cancel callback ringing (Automatic Callback Busy Cancel)
PT/SLT/PS
Off-hook.
Setting Callback on an ISDN Line (Completion of Calls to Busy
Subscriber [CCBS])
You can set the telephone to receive callback ringing when a busy called party on an ISDN line becomes free.
When you answer the callback ringing, the called party's telephone number is automatically dialled.
PT/SLT/PS
While hearing a busy tone
6
C.Tone
Enter 6.
outside
phone no.
Dial outside phone
number.
4 6
C.Tone
Enter 46.
On-hook.
1.2.4 When the Dialled Line is Busy or There is No Answer
Talk.
On-hook.
User Manual 37