Fault isolation in a serial-looped transmission system
US4002847A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 29, 1975 |
| Grant date | Jan 11, 1977 |
| Priority date | — |
| Expiry date | Dec 29, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q11/04
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A serial looped transmission system is disclosed which includes a central terminal and a number of remote terminals for two-way communication between the various terminals on a single looped transmission facility. Each terminal includes multiplexing and demultiplexing equipment for taking signals off and placing signals on the common transmission line. Failures in any link of this system cause the entire system to fail. Loopbacks placed at each terminal permit restoration of service to the operative portion of the system. Testing the system in order to place such loopbacks is accomplished by common timing and testing equipment at the central terminal which takes into account the variances in start-up time for different sizes of the operating system. Loopback instabilities due to timing variances are overcome by placing the central terminal in overall control of the loopback sequence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.