Asynchronous communications system
US4803481A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1987 |
| Grant date | Feb 7, 1989 |
| Priority date | — |
| Expiry date | Mar 30, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/40
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The communications system uses a master line, a slave line and at least one call line to effect true asynchronous communication. A protocol is established whereby a master unit takes control of the call line when the master line and slave line are at the same logical state. The slave unit has control of the call line when the master line and slave line are at different logical states. The system includes an interchange device which routes communications signals in accordance with channel identification commands sent over the communications system. The communications scheme can be implemented on a wide variety of digital communicating devices through the use of a universal command instruction set which provides the data manipulation functions required by most microprocessors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.