EP 0254125 B1 19910213 - DANGER SIGNALLING SYSTEM
Title (en)
DANGER SIGNALLING SYSTEM
Publication
Application
Priority
DE 3623295 A 19860710
Abstract (en)
[origin: EP0254125A1] Danger alarm system with a control centre (Z) with an analyser and several two-wire signalling leads (ML) to which a plurality (i) of individually identifiable detectors (Mi) are connected in a chain arrangement; each of these has a controllable switch (STi) in one of the two wire leads (b). The detectors (Mi) are scanned cyclically from the control centre for their current status, each detector (Mi) switching the next detector (Mi + 1) through to the signalling lead (ML) after a time delay (ZG) dependent on its measured value and sends a current pulse on the signalling lead. In the analyser, the detector address and its measured value are determined from the respective time of the current pulse (li) and from these an alarm or malfunction indication is obtained. In accordance with the invention, a number of status scanning cycles (ZAZ) are carried out in sequence by the control centre (Z) and, in the case of a change of status or for any other reason, regular scanning cycles (RAZ) are carried out in which the detector address is also determined. The status scanning cycle uses a scan voltage (U3) which deviates from the scan voltage (U2) used for the regular scanning cycle (RAZ). For the status scanning (ZAZ), each detector (Mi) has additionally a comparator element (K) which switches the following detector (Mi + 1) through with no time delay. <IMAGE>
IPC 1-7
IPC 8 full level
G08B 26/00 (2006.01)
CPC (source: EP)
G08B 26/005 (2013.01)
Designated contracting state (EPC)
AT BE DE FR GB IT NL SE
DOCDB simple family (publication)
EP 0254125 A1 19880127; EP 0254125 B1 19910213; AT E60885 T1 19910215; DE 3768019 D1 19910321
DOCDB simple family (application)
EP 87109814 A 19870707; AT 87109814 T 19870707; DE 3768019 T 19870707