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1.1.13.
Line Monitor Circuit
The Line Monitor Circuit consists of an operational DAA (The secondary side chip) and its peripheral
circuits.
Its function is to monitor the dial tone, DTMF tone, response signals, etc. over the speaker. It also sounds
the output of the key touch tones, alarm tones, etc. from the panel CPU over the speaker. The Received
Signals are output from DAA of Secondary circuit, and through Analog AGC, Electronic Volume, Amplifier
and over the speaker.
The monitor tone from the phone line and the buzzer tone from the panel can be adjusted from the Control
Panel.
circuits.
Its function is to monitor the dial tone, DTMF tone, response signals, etc. over the speaker. It also sounds
the output of the key touch tones, alarm tones, etc. from the panel CPU over the speaker. The Received
Signals are output from DAA of Secondary circuit, and through Analog AGC, Electronic Volume, Amplifier
and over the speaker.
The monitor tone from the phone line and the buzzer tone from the panel can be adjusted from the Control
Panel.
Analog AGC
Electronic Volume
(Monitor)
DAA
(Secondary)
Si3021
Amplifier
Electronic Volume
(Buzzer)
Buzzer Signal from Panel
AOUT
Speaker
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