Ringing Signal Generator Circuit; Smdr Interface Circuit - Panasonic KX-TEA308NE Service Manual

KX-TEA308NE

11.15. RINGING SIGNAL GENERATOR CIRCUIT

This section generates the ring signal for the single line telephone. A 20/25Hz square wave is generated by the CPU timer and sent
to low pass filter and the Ring signal is amplified by BELL amplifier circuit, and then passed it through the ringing signal switching
relay to the single line telephone.

11.16. SMDR INTERFACE CIRCUIT

This is the RS-232C interface port. When the port is connected to a printer, the port can be used to output the SMDR feature
recording messages and the contents of the system program.
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