Emergency alert system
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Jul 2, 1991
Grant Date -
N/A
app pub date -
Feb 2, 1990
filing date -
Feb 2, 1990
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
An alarm system suitable for use in a telecommunications network in which a central switching system is capable of selectively providing a signal of a predetermined polarity to a plurality of remotely located stations without being dependent upon or impeding the ability of the central switching system to process relatively high volume communications traffic. Each of the remote stations is connected to the telecommunications network by an electrical conduction path. The stations are substantially unresponsive to the predetermined polarity signal. In response to an alarm indication signal, the system effects a reversal in the polarity of the signal provided to a selected subset of the remote stations. Each station in the selected subset responds to the polarity reversal by indicating an alarm condition.
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Family
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