Telephonic communications – Diagnostic testing – malfunction indication – or electrical... – Monitoring
Patent
1989-10-30
1993-02-09
Dwyer, James L.
Telephonic communications
Diagnostic testing, malfunction indication, or electrical...
Monitoring
379 40, 379 50, 379 59, H04M 1104, H04Q 704
Patent
active
051857790
ABSTRACT:
A cellular backup system is provided for a standard security alarm network, so that upon the inoperativeness of the telephone land line, automatic switch over to the cellular system is achieved, so that a digital communicator or teleophone tape dialer may still transmit its distress call to a central alarm station, via the cellular system. A line fault monitor is provided which automatically detects the outage of the land-based telephone system which, in turn, provides an output signal to a latching relay which causes the activation of a pair of switching relays to automatically switch the connection of the alarm communicator from the DB-8 cord of the land-based system to a cellular interface coupled to a conventional cellular transceive of a cellular system. The switching relays are latched in the state connecting the alarm communicator to the cellular backup system and held in such a state, regardless of the state of the land-based system, as long as a manual rest switch has not been used. The pair of switching relays are also used for coupling a standard land telephone handset also to the cellular system upon the outage of the land-based lines.
REFERENCES:
patent: 4465904 (1984-08-01), Gottsegen et al.
patent: 4718079 (1988-01-01), Rabito
patent: 4731810 (1988-03-01), Watkins
patent: 4868859 (1989-09-01), Sheffer
Stewart Crump, Jr., "AB1X: Landline Emulator for Cellular", Personal Communications Technology, Jun. 1986, pp. 39 and 42.
Security, May 1987; p. 18, "Cellular Communications Goes Off-Road to Transmit Alarms".
Security Magazine, "SDM News", May 1987.
Dop Dennis B.
Freitag Michael G.
Zawacki Norbert W.
Azulay Y. Judd
Chan Wing F.
Dwyer James L.
Zawacki Norbert
LandOfFree
Cellular alarm backup system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cellular alarm backup system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cellular alarm backup system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-329511