Calling Line Identification Circuit - Panasonic KX-FHD332C Service Manual

7.9.7. CALLING LINE IDENTIFICATION CIRCUIT

1. Function
This unit is compatible with the Caller ID service offered by your
local telephone company. To use this feature, you must subscribe
to a Caller ID service. The data for the caller ID from the telephone
exchange is sent during the interval between the first and second
rings of the bell signal. The data from the telephone exchange is a
modem signal which is modulated in an FSK (Frequency Shift
Keying) format. Data "0" is a 1200 Hz sine wave, and data 1 a 2200
Hz sine wave.
There are two type of the message format which can be received:
i.e.the single data message format and multiple data message
format.
The multiple data format allows to transmit the name and data
code information in addition to the time and telephone number
data.
When there is multiple data in the unit, the name or telephone
number are displayed.
2. Circuit Operation:
The caller ID signal input from TEL LINE is processed with
MODEM (IC505).
Refer to CHECK SHEET () for the route of caller ID signal.
187