Circuit Operation - Panasonic KX-FP80C Service Manual

# EXTERNAL TAM OPERATION
1 When the bell signal rings as many times as
the number memorized into the connected
answering machine (TAM), the answering
machine is connected to the line and the
answering message is sent out to the line.
(OGM out for 8 ~ 16 sec.)
2 After sending the OGM, the answering
machine starts to record the message of the
other party (ICM recording).
Attention 1:
No sound detection lasts 20 seconds after the telephone call is received at the answering
machine. If there is no sound for more than 5 seconds (#701 in the service mode), it switches to
the facsimile.
Attention 2:
When the answering machine cannot answer the telephone call because of disconnection or the
recording tape is full, the unit picks up the call after 5 rings (#702 in the service mode). Then it
switches to the facsimile.

6.10.2. CIRCUIT OPERATION

The TAM INTERFACE circuit consists of an EXT. TAM HOOK detection circuit, CNG signal from
the other party's detection circuit, VOX detection circuit (to judge sound/no-sound) and RL101 (to
separate EXT. TAM).
1. EXT. TAM HOOK detection circuit
A bell is received at EXT. TAM and EXT. TAM is connected to the
line, making a DC LOOP. Then, PC101 detects this voltage. During
The length of the answering message
should be 8~16 seconds.
While the message is being played, the unit
starts to detect the CNG signal.(A)
If the unit detects the CNG signal, it will
switch to FAX receiving and disconnect the
external TAM automatically.
After the OGM of the external TAM is
finished, the unit starts to detect
approximately 5 seconds of no sound
detection. (B)
If no sound is detected, the unit will switch
to FAX receiving and disconnect the
external TAM automatically.
If the unit cannot detect the CNG signal or
no sound for about 30 seconds, the unit will
disconnect the line. (C)
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UNIT OPERATION