Data Communication - Panasonic KX-T7633 Service Manual

10.6. DATA COMMUNICATION

Function
The data communication circuit serves the following functions:
Information exchanger between PBX and proprietary telephone, key input information as well as
data for the LED control, LCD control, voice data, etc. This information is continuously
exchanged at all times.
Circuit Operation
The data received from PBX is inputted to the comparator(pin 68) built in IC5 through Pulse Trans
T1. The threshold voltage of the comparator is determined by R62 to 64 and inputted to pin 67
and 29.
The data to PBX is outputted from pin 70 and 71 of IC5, drives T1 by Transistor Q2 and
transmitted.
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