EP 0248298 B1 19910130 - DANGER ALARM INSTALLATION
Title (en)
DANGER ALARM INSTALLATION
Publication
Application
Priority
CH 224586 A 19860603
Abstract (en)
[origin: US4757303A] In an alarm system with a number of alarm devices such as fire intrusion alarm devices connected to a signal center, upper and a lower thresholds are defined in the alarm devices, with the inactive value of the sensor output signal located between the threshold limits. The alarm devices transmit one of three indication signals to the signal center depending on whether an alarm sensor output is above an upper limit, below a lower limit or between the upper and lower limits, with these alarm state signals being produced by threshold detectors. Also, it is possible to adjust the two threshold limits of the alarms to compensate for changing ambient conditions over extended periods of time. When the sensor output signal reaches one of the upper or lower thresholds both the upper and lower threshold limits either move up or down, respectively, so that the sensor output signal is once again located between the upper and lower threshold limits. The signal center receives the outputs of the threshold detectors and differentiates between five different states, namely the alarm states "normal," "warning," "alarm," "maintenance" and "malfunction", on the basis of the frequency and the type of these signals.
IPC 1-7
IPC 8 full level
G08B 17/00 (2006.01); G08B 25/04 (2006.01); G08B 29/18 (2006.01); G08B 29/26 (2006.01)
CPC (source: EP US)
G08B 17/00 (2013.01 - EP US); G08B 25/04 (2013.01 - EP US); G08B 29/22 (2013.01 - EP US); G08B 29/24 (2013.01 - EP US); G08B 29/26 (2013.01 - EP US)
Designated contracting state (EPC)
CH DE FR GB IT LI SE
DOCDB simple family (publication)
EP 0248298 A1 19871209; EP 0248298 B1 19910130; CH 669859 A5 19890414; DE 3767772 D1 19910307; NO 170373 B 19920629; NO 170373 C 19921007; NO 872296 D0 19870601; NO 872296 L 19871204; US 4757303 A 19880712
DOCDB simple family (application)
EP 87107535 A 19870523; CH 224586 A 19860603; DE 3767772 T 19870523; NO 872296 A 19870601; US 5716187 A 19870601