Fire alarm system
US4525700A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1983 |
| Grant date | Jun 25, 1985 |
| Priority date | — |
| Expiry date | Oct 27, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B26/002
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A fire alarm system has a main unit and a plurality of sensor terminals in accordance with a polling system. The plurality of sensor terminals are divided into a plurality of groups. When a given sensor terminal of a given group is accessed and transmits digital data as response data indicating a smoke concentration or a temperature to the main unit, and the response data exceeds a first reference value thereby indicating that a fire has broken out, the main unit accesses other sensor terminals of the given group. If some of the response data therefrom exceed a second reference value which is equal to or smaller than the first reference value, the main unit counts the number of such sensor terminals. When the number exceeds a predetermined number, the main unit displays information indicating the existence of a fire.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.