Method for transmitting measuring values in a fire alarm system and apparatus for the performance of the aforesaid method
US4404548A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 1981 |
| Grant date | Sep 13, 1983 |
| Priority date | — |
| Expiry date | Jun 8, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B17/00
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
In a fire alarm system individual fire alarms are connected in series by reporting lines with a central signal station. In order to be able to connect a greater number of fire alarms with the individual reporting or signaling lines and/or in order to be able to dispatch an increased amount of current through the reporting lines, the reporting or signaling lines from the last fire alarm of a line are returned back to the central signal station in the form of a ring circuit or loop. Upon the absence of signals at a reporting line an interrogation device is reversed, so that there can be ensured that in the event of a line disturbance or breakdown of a fire alarm the remainder of the fire alarms still can be utilized for giving a signal. The individual fire alarms are structured such that during assembly the inputs and outputs can be mutually interchanged.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.