Stand alone mode for alarm-type module
US5721530A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 1997 |
| Grant date | Feb 24, 1998 |
| Priority date | — |
| Expiry date | Apr 1, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B26/001
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
There is provided an alarm system for detecting and warning of the presence of alarm and trouble conditions in a plurality of zones. The system comprises a loop controller having supply lines extending to the plurality of zones and a module connected to the supply lines within each zones. The module includes means for detecting whether communication between the module and the loop controller has been disrupted. If an alarm condition occurs in a particular zone, the module initiates communication of the alarm condition to the loop controller. During normal operation, when communication with the loop controller has not been disrupted, the module has shared operations with the loop controller to determine whether an alarm condition exists. When communication with said loop controller has been disrupted, temporarily or otherwise, the module continues to operate independently of the loop controller and determines whether an alarm condition exists.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.