11
KX-TS2388RUB/KX-TS2388RUW/KX-TS2388CAB/KX-TS2388CAW/KX-TS2388UAB/KX-TS2388UAW
4.2.6.
Caller ID Detect Circuit
4.2.6.1.
Function (FSK Signal)
The caller ID is a changeable 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 sec-
ond 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 types of the message for-
mat which can be received: i.e. the single message format and plural message format. The plural message format allows to trans-
mit the name and data code information in addition to the time and telephone number data.
•
FSK (Frequency Shift Keying) format
4.2.6.2.
Circuit Operation
Caller ID signal is sent through the circuit via the following path :
LINE
C500/C520
C551/C552
R551/R552
R553/R554
IC801 (pin 92, 93)
STD Ring / 20Hz
Tip-Ring
FSK
DATA in
1st Ring
Silent interval
2nd Ring
DATA
0.1Vrms
70Vrms
1300Hz or
1200Hz
=DATA "0"
2100Hz or
2200Hz
=DATA "1"
