US4953181A
Expired / Lapsed
US
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Apparatus and method for detecting digital carrier synchronization problems
Assignee: Lear Siegler Jennings Corp
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Filing: 1989-03-08
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Granted: 1990-08-28
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Expires: 2009-03-08
Abstract
Abstract Phase slippage of a test clock signal and the direction of such slippage are digitally detected, accumulated, and displayed and/or recorded. A test clock signal is recovered from one digital carrier signal. A reference clock signal is recovered from another digital carrier signal. From the test clock signal, first and second binary signals are generated at a frequency phase synchronized to the test clock signal. The second signal is shifted in phase from the first signal. Responsive to the reference clock signal, the states of the first and second signals are repeatedly sampled such that the sampled states are representative of the phase relationship between the test clock signal and the reference clock signal. Successive samples of the states of the first and second signals are compared to detect unit interval phase shifts between the test clock signal and the reference clock signal. The phase shifts detected by the comparison are accumulated at successive samples are compared to represent phase slippage. An annular display of lamps that facilitates observation of the accumulated slippage.
Inventors
- 👤 Francis P. Keiper, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:27
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/20; H04L1/205
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
154 words
Apparatus to display phase slippage in a digital carrier system comprising: means for detecting phase slippage of a digital carrier test signal from a digital carrier reference signal; a first bank of n binary indicators arranged in predetermined positions, where n is a positive integer; a second bank of m binary indicators arranged in predetermined positions, where m is a positive integer; means for actuating only one binary indicator of the first bank and other one binary indicator of the second bank; first means responsive to the detecting means for operating the actuating means to sequence the actuated indicator of the first bank one indicator position each time the test signal slips one unit interval; and second means responsive to the detecting means and the first operating means for operating the actuating means to sequence the actuated indicator of the second bank one indicator position each time the test signal slips n unit intervals.
Claim 2
Dependent Claim
154 words
Apparatus to display phase slippage in a digital carrier system comprising: means for detecting phase slippage of a digital carrier test signal from a digital carrier reference signal; a first bank of n binary indicators arranged in predetermined positions, where n is a positive integer; a second bank of m binary indicators arranged in predetermined positions, where m is a positive integer; means for actuating only one binary indicator of the first bank and other one binary indicator of the second bank; first means responsive to the detecting means for operating the actuating means to sequence the actuated indicator of the first bank one indicator position each time the test signal slips one unit interval; and second means responsive to the detecting means and the first operating means for operating the actuating means to sequence the actuated indicator of the second bank one indicator position each time the test signal slips n unit intervals.
Claim 3
Dependent Claim
12 words
The apparatus of claim 1 in which, the binary indicators are lamps.
Claim 4
Dependent Claim
18 words
The apparatus of claim 2, in which the lamps of the first and second banks are different colors.
Claim 5
Dependent Claim
51 words
The apparatus of claim 2, in which the first sequencing means sequences the lit lamp of the first bank one lamp position in one direction each time the test signal lags one unit interval and one lamp position in the other direction each time the test signal leads one unit interval.
Claim 6
Dependent Claim
57 words
The apparatus of claim 4, in which the second sequencing means sequences the lit lamp of the second bank one lamp position in one direction each time the first bank sequences n lamp positions in one direction and one lamp position in the other direction each time the first bank sequences n positions in the other direction.
Claim 7
Dependent Claim
44 words
The apparatus of claim 5, additionally comprising an index indicator lamp, means responsive to the detecting means, the first sequencing means and the second sequencing means for lighting the index lamp each time the second bank sequences m lamp positions in the same directions.
Claim 8
Dependent Claim
58 words
The apparatus of claim 6, additionally comprising a first direction indicator lamp, a second direction indicator lamp, means responsive to the detecting means for lighting the first direction indicator lamp each time the first bank sequences in one direction, and means for lighting the second direction indicator lamp each time the first bank sequences in the other direction.
Claim 9
Dependent Claim
17 words
The apparatus of claim 7, in which the first bank of lamps is arranged in a ring.
Claim 10
Dependent Claim
22 words
The apparatus of claim 8, in which the second bank of lamps is arranged in a ring lying within the first bank.
Claim 11
Dependent Claim
14 words
The apparatus of claim 9, in which n is sixteen and m is twelve.
Claim 12
Dependent Claim
58 words
The apparatus of claim 4, additionally comprising a first direction indicator lamp, a second direction indicator lamp, means responsive to the detecting means for lighting the first direction indicator lamp each time the first bank sequences in one direction, and means for lighting the second direction indicator lamp each time the first bank sequences in the other direction.
Claim 13
Dependent Claim
58 words
The apparatus of claim 5, additionally comprising a first direction indicator lamp, a second direction indicator lamp, means responsive to the detecting means for lighting the first direction indicator lamp each time the first bank sequences in one direction, and means for lighting the second direction indicator lamp each time the first bank sequences in the other direction.
Claim 14
Dependent Claim
17 words
The apparatus of claim 2, in which the first bank of lamps is arranged in a ring.
Claim 15
Dependent Claim
22 words
The apparatus of claim 13, in which the second bank of lamps is arranged in a ring lying within the first bank.
Claim 16
Dependent Claim
14 words
The apparatus of claim 14, in which n is sixteen and m is twelve.
Claim 17
Dependent Claim
15 words
The apparatus of claim 6, in which n times m is one hundred ninety two.
Claim 18
Dependent Claim
41 words
The apparatus of claim 6, additionally comprising a frame slip counter and means responsive to the detecting means, the first sequencing means and the second sequencing means for incrementing the frame slip counter each time the index indicator lamp is lit.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |