Calling Line Identification Circuit (Caller Id) - Panasonic KX-TG2650N Service Manual

12.8. Calling Line Identification Circuit (Caller ID)

Function: / The caller ID is a chargeable ID which the user of a telephone circuit obtains by
entering a contract with the telephone company to utilize a caller ID service. For this reason, the
operation of this circuit assumes that a caller ID service contract has been entered for the circuit
being used. / 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 message format and plural message format. The plural message
format allows to transmit the name and data code information in addition to the time and
telephone number data.
58