Telephone exchange signalling unit
US4129756A · kind A · utility
2Cited by
5References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1977 |
| Grant date | Dec 12, 1978 |
| Priority date | — |
| Expiry date | Sep 20, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q11/04
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A telephone exchange signalling unit is provided having looping means for feeding back and comparing transmitted data multiplets directly with its input data. This test is ordered by the control unit of the telephone exchange without the necessity of using wires other than the distribution and scan wires of the telephone exchange and the signalling unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.