Method and apparatus for testing tone generators
US4218589A · kind A · utility
0Cited by
3References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1979 |
| Grant date | Aug 19, 1980 |
| Priority date | — |
| Expiry date | Mar 28, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q11/0407
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Apparatus and methods for testing digital tone generators in a digital time division, multiplex telecommunications switching system. The tone generator produces both continuous and interrupted tones, and testing of any tone is accomplished by determining if its successive PCM words are stuck-at-dc. (SDD) and if it is an idle tone (ITD). The combinations of ITD and SDD determine whether (i) the tone generator being tested is malfunctioning, (ii) the test method or apparatus itself has failed, or (iii) the tone generator is functioning properly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.