Two-wire multi-zone alarm system
US4359721A · kind A · utility
15Cited by
8References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1978 |
| Grant date | Nov 16, 1982 |
| Priority date | — |
| Expiry date | Oct 16, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B25/04
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A multi-zone alarm system operative with a two-wire alarm loop and having a simple network at each alarm sensor for providing a coded signal indicative of sensor identity and relatively simple circuitry at a central location for interrogation of the remote sensors and determination of those sensors providing an alarm signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.