US3692939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Test arrangement for data modem
Assignee: General Electric Co
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Filing: 1971-04-05
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Granted: 1972-09-19
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Expires: 1991-04-05
Abstract
Abstract A data modem is provided with loop-back circuits between the modem transmitter and receiver. If the modem is operating, the loop-back circuits cause oscillations. In addition, the oscillations can also indicate the operating condition of the modem so that adjustments can be made if needed.
Inventors
- 👤 Patrick E Knight
- 👤 Raymond D Stapleton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:58
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/24; H04L1/242; H04L1/243
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
130 words
In a data modem having a transmitter with a direct current data input and an alternating current line output, and having a receiver with an alternating current line input and a direct current data output, an improved arrangement for testing said data modem comprising: a. first means for selectively connecting said alternating current line output of said transmitter to said alternating current line input of said receiver; b. second means for selectively connecting said direct current data output of said receiver to said direct current data input of said transmitter in reverse-polarity fashion; c. and indicating means connected to said second means for indicating the operation of said data modem in response to the self-oscillations produced as a result of the connections provided by said first and second connecting means.
Claim 2
Dependent Claim
130 words
In a data modem having a transmitter with a direct current data input and an alternating current line output, and having a receiver with an alternating current line input and a direct current data output, an improved arrangement for testing said data modem comprising: a. first means for selectively connecting said alternating current line output of said transmitter to said alternating current line input of said receiver; b. second means for selectively connecting said direct current data output of said receiver to said direct current data input of said transmitter in reverse-polarity fashion; c. and indicating means connected to said second means for indicating the operation of said data modem in response to the self-oscillations produced as a result of the connections provided by said first and second connecting means.
Claim 3
Dependent Claim
28 words
The improved testing arrangement of claim 1 wherein said indicating means comprises a direct current voltmeter that has a zero indication, a positive indication, and a negative indication.
Claim 4
Dependent Claim
74 words
The improved testing arrangement of claim 1 wherein said first means disconnect any communication circuit from said modem in response to said alternating current line output of said transmitter being connected to said alternating current line input of said receiver, and wherein said second means disconnect any terminal equipment from said modem in response to said direct current data output of said receiver being connected to said direct current data input of said transmitter.
Claim 5
Dependent Claim
28 words
The improved testing arrangement of claim 3 whereiN said indicating means comprise a direct current voltmeter that has a zero indication, a positive indication, and a negative indication.
Claim 6
Dependent Claim
16 words
The improved testing arrangement of claim 4 wherein said first and second connecting means operate simultaneously.
References Cited (Backward Citations)
US3371165A
Cited
US3571530A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-19 | 1976-03-20 | 1976-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-19 | 1980-03-20 | 1980-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-19 | 1984-03-20 | 1984-09-19 | $7700.00 | Window Closed / Lapsed |