Tone selective key telephone intercom system including digital t

Details Tone selective key telephone intercom system including digital t Tone selective key telephone intercom system including digital t

1977-08-25

1979-06-12

Claffy, Kathleen H.

179 84VF, H04M 172, H04M 150

Patent

active

041581105

ABSTRACT:
The system receives subscriber station address information in the form of frequency coded tone signals transmitted from a calling station along a common intercom circuit, and selectively accesses a called subscriber station having a corresponding station address in order to produce a call indication ring-out thereat. The system is comprised of decoder circuitry including a digital multi-frequency tone detector for receiving and decoding station address information transmitted from a calling station, and access circuitry operatively associated with the tone detector for routing an appropriate call indication signal to the called station. Signals which appear at the output of the tone detector are delivered to the access circuitry which, in turn, initiates the call indication sequence and routes additional signals back to the tone detector for controlling it during call indication. The system is suitable for use with 10, 19, 36 or varying numbers of subscriber stations and may include, for applications having more than 10 subscriber stations, appropriate transfer and associated output control circuitry for double digit operation.

REFERENCES:
patent: 3609249 (1971-09-01), Pinede
patent: 3739100 (1973-06-01), Cartwright
patent: 3790720 (1974-02-01), Schartmann
patent: 3917912 (1975-11-01), Niwa
patent: 3935395 (1976-01-01), Ball et al.
patent: 3941944 (1976-03-01), McIntosh
patent: 4044206 (1977-08-01), Champan et al.

Affiliated with

Also associated with

Rating

Tone selective key telephone intercom system including digital t does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Tone selective key telephone intercom system including digital t, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tone selective key telephone intercom system including digital t will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1110297