Panasonic KX-TES824LA Service Manual page 221

KX-TES824LA / KX-TEM824LA /
26.5.6. DTMF Receiver Circuit
26.5.6.1. Composition
The DTMF receiver circuit is composes of two DTMF receivers.
IC510 and IC511 are used for the DTMF receivers from SLT connected to the extension.
The DTMF signal is the 4bit parallel data and read by ASIC.
26.5.7. INT CALLID Interface Circuit
By using the DSP built into the ASIC, it is possible to produce CALLID signal and send it through the cross point to each extension.
The CALLID signal can be switched between FSK and DTMF. There are three sources of the extension CALL ID in the system.
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