EP 0125387 B1 19870114 - RISK SIGNALLING METHOD AND APPARATUS
Title (en)
RISK SIGNALLING METHOD AND APPARATUS
Publication
Application
Priority
CH 237583 A 19830429
Abstract (en)
[origin: US4551710A] In an alarm system a central signal station periodically transmits interrogation signals, preferably in the form of infrared radiation packets to remotely located detectors which transmit a response signal back to the central signal station after differing time delays that are characteristic for the individual detectors and which permit the localization of the source of the response signal. In an alarm state, the detectors respond to every interrogation signal, in the normal operational state to only every mth interrogation signal, i.e. less often, and in a state of diminishing battery potential to only every small pth interrogation signal, i.e. even less often. The state of the individual detectors is determined from the frequency with which the response signals are transmitted back by the detectors, that is the ratio of the response signals to the interrogation signals.
IPC 1-7
IPC 8 full level
G08B 25/00 (2006.01); G08B 26/00 (2006.01); G08B 29/16 (2006.01); G08B 29/18 (2006.01)
CPC (source: EP US)
G08B 26/004 (2013.01 - EP US); G08B 29/16 (2013.01 - EP US); G08B 29/181 (2013.01 - EP US)
Citation (examination)
DE 2533330 A1 19770127 - SIEMENS AG
Designated contracting state (EPC)
CH DE FR GB IT LI SE
DOCDB simple family (publication)
EP 0125387 A1 19841121; EP 0125387 B1 19870114; CA 1222554 A 19870602; DE 3462075 D1 19870219; DK 107784 A 19841024; DK 107784 D0 19840227; JP S59218595 A 19841208; NO 841529 L 19841024; US 4551710 A 19851105; YU 68284 A 19871031
DOCDB simple family (application)
EP 84101105 A 19840203; CA 451508 A 19840406; DE 3462075 T 19840203; DK 107784 A 19840227; JP 8763084 A 19840428; NO 841529 A 19840416; US 60212784 A 19840419; YU 68284 A 19840413