US3683115A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arrangement to supervise the operation of coder and decoder circuits in a pcm-tdm system
Assignee: International Standard Electric Corp
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Filing: 1969-07-15
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Granted: 1972-08-08
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Expires: 1989-07-15
Abstract
Abstract The coder and decoder of a terminal are placed in a closed loop excluded from the normal transmission lines during sync time and/or signalling time. During this time a low frequency test signal is applied to the coder and a comparison circuit. By gate means the output of the coder is directly coupled to the decoder of the same terminal. The output of the decoder is coupled to the comparison circuit. The comparison circuit will produce a fault indication when the difference between the two input signals applied thereto exceeds a predetermined amount. Continuous supervision over the whole range of the coder and decoder, without influencing the intelligence paths, is possible provided the waveform and frequency of the test signal is properly chosen.
Inventors
- 👤 Arnold Albert Schellenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:56
CPC Classifications
H; H04; H04J; H04J3/00; H04J3/02; H04J3/14; H03; H03M; H03M1/00; H03M1/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
169 words
An arrangement to supervise the operation of a coder and a decoder in one terminal of a pulse code modulation-time division multiplex system having a multiplex signal including a plurality of channel time slots, a synchronization time slot and a signalling time slot comprising: a test signal generator; first means coupled to said generator and said coder to couple said test signal to the input of said coder during at least one of said synchronization and signalling time slots; second means coupled to said coder and said decoder to couple the output signal of said coder to the input of said decoder during said one of said synchronization and said signalling time slots; and third means coupled to said generator and the output of said decoder during said one of said synchronization and said signalling time slots to produce a fault indication when the amplitude of the difference between the amplitude of said test signal and the amplitude of the output signal of said decoder exceeds a predetermined amplitude.
Claim 2
Dependent Claim
169 words
An arrangement to supervise the operation of a coder and a decoder in one terminal of a pulse code modulation-time division multiplex system having a multiplex signal including a plurality of channel time slots, a synchronization time slot and a signalling time slot comprising: a test signal generator; first means coupled to said generator and said coder to couple said test signal to the input of said coder during at least one of said synchronization and signalling time slots; second means coupled to said coder and said decoder to couple the output signal of said coder to the input of said decoder during said one of said synchronization and said signalling time slots; and third means coupled to said generator and the output of said decoder during said one of said synchronization and said signalling time slots to produce a fault indication when the amplitude of the difference between the amplitude of said test signal and the amplitude of the output signal of said decoder exceeds a predetermined amplitude.
Claim 3
Dependent Claim
28 words
An arrangement according to claim 1, wherein each of said first and second means includes switch means closed during said one of said synchronization and signalling time slots.
Claim 4
Dependent Claim
89 words
An arrangement according to claim 1, wherein said second means includes a first gate means coupled to the output of said coder closed during said one of said synchronization and said signalling time slots in the transmitting portion of said terminal, storage means coupled to the output of said first gate means, and a second gate means coupled to the output of said storage means and the iNput of said decoder during said one of said synchronization and said signalling time slots in the receiving portion of said terminal.
Claim 5
Dependent Claim
70 words
An arrangement according to claim 1, wherein said third means includes fourth means coupled to said decoder and said generator to produce a control signal proportional to the difference between the amplitude of said test signal and the amplitude of the output signal of said decoder, and fifth means coupled to said fourth means to produce said fault indication when the amplitude of said control signal exceeds a predetermined amplitude.
Claim 6
Dependent Claim
15 words
An arrangement according to claim 4, wherein said fourth means includes an amplitude comparison circuit.
Claim 7
Dependent Claim
13 words
An arrangement according to claim 5, said comparison circuit includes a differential amplifier.
Claim 8
Dependent Claim
23 words
An arrangement according to claim 4, wherein said fifth means includes an analog-to-digital converter having a threshold level equal to said predetermined amplitude.
Claim 9
Dependent Claim
23 words
An arrangement according to claim 7, wherein said converter includes A Schmitt trigger circuit having a threshold level adjusted to said predetermined amplitude.
Claim 10
Dependent Claim
32 words
An arrangement according to claim 4, wherein said fourth means includes an amplitude comparison circuit; and said fifth means includes an analog-to-digital converter having a threshold level equal to said predetermined amplitude.
Claim 11
Dependent Claim
146 words
An arrangement according to claim 9, wherein said first means includes first switch means coupled to said generator and the input of said coder and closed during said one of said synchronization and signalling time slots, in the transmitting portion of said terminal; said second means includes second switch means coupled to the output of said coder and closed during said one of said synchronization and signalling time slots in the transmitting portion of said terminal, storage means coupled to the output of said second switch means, and third switch means coupled to the output of said storage means and the input of said decoder during said one of said synchronization and signalling time slots in the receiving portion of said terminal; said comparison circuit includes a differential amplifier; and said converter includes a Schmitt trigger circuit having a threshold level adjusted to said predetermined amplitude.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |