Message-waiting and do-not-disturb communications system
US4086441A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1977 |
| Grant date | Apr 25, 1978 |
| Priority date | — |
| Expiry date | Jan 14, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/436
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The system includes a central station console and one or more remote station modules. Corresponding message-waiting indicators mounted by the central station console and each remote station module are accessed and controlled from the central station on a selective individual basis; but can be controlled alternatively from the remote station modules in order to indicate message-received. Corresponding do-not-disturb indicators mounted by the central station console and each remote station module are controlled exclusively from the latter. For telephone application, the do-not-disturb indicators additionally may be operated in a flashing mode when the associated telephone set assumes off-hook condition in order to provide call status indication. The central station message-waiting and do-not-disturb indicators are connected electrically with corresponding remote station indicators by individual signalling paths, each consisting of a pair of electrical conductors along which bidirectional current flow respectively constitutes the message-waiting (or message-received) and do-not-disturb signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.