Panasonic KX-F780 Operating Instructions Manual page 25

Receiving both voice and fax calls (TEL/FAX mode)
Use this mode when you wish to receive voice calls with ring but do not want to hear the unit ring when faxes
are received.
When a call is received, the unit will work as follows.
The unit will automatically answer a call without ringing.
(At this point, a telephone fee will be charged to the caller.)
If extension telephones are connected, they will only ring before the call is answered. \1
The unit will now distinguish between a voice and fax call by detecting the calling tone.
The unit will receive a document.
Silent ring fax recognition system
\1 The number of rings can be changed. See "Setting the TEL/FAX mode ring count" on page 26.
\2 The number of rings can be changed. See "Setting the silent fax recognition ring count" on page 27.
Note:
¡Some fax messages that are transmitted manually may not send a calling tone. These calls must be
manually received.
¡You can record the TEL/FAX greeting message (see page 54).
A call is received.
Fax call Voice call
The unit will start to ring. \2
While ringing, the unit will emit a different
ring back tone to the calling party.
Answer the call using the speakerphone
or the handset. If you do not answer the
call, the facsimile unit will switch to the
fax.
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