Panasonic KX-TG5771BXS, Service Manual, Page: 20 / 123

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KX-TG5771BXS/KX-TGA570BXS
4.5.8. Calling Line Identification (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 Caller-ID data from exchange is supplied to the telephone using either method of FSK or DTMF. The method is chosen
according to the exchange of telephone office. This unit is available to receive the data with both methods and displays the
received data on LCD.
• FSK (Frequency Shift Keying) format
• DTMF format
It is the method to send the telephone number of calling party with DTMF to the telephone. DTMF is sent before the first bell sig-
nal.
The data is sent in turn; first the start code, secondly the telephone number of calling party, lastly end code.
The DTMF is chosen from A (1633 Hz and 697 Hz), B (1633 Hz and 770 Hz), C (1633 Hz and 852 Hz) and D (1633 Hz and
941 Hz) as the start code and end code according to the exchange.