Detecting, localizing and ranking copper connectors

Patent metadata

Field	Value
Publication number	US-9846188-B2
Application number	US-201414489548-A
Country	US
Kind code	B2
Filing date	Sep 18, 2014
Priority date	Sep 18, 2014
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

A method for detecting failures in electrical cable assemblies is provided. A cable test instrument obtains frequency domain data representing electrical characteristics of a cable link under test. A number of connectors in the cable link under test is determined based on the obtained frequency domain data. An estimated location of each of the connectors along the length of the cable link under test is determined by the cable test instrument. The connectors are ranked in accordance with their respective contribution to detected failures in the cable link under test.

First claim

What is claimed is:

1. A computer-implemented method for detecting failures in electrical cabling assemblies, the method comprising:
obtaining, by a cable test instrument, frequency domain data representing electrical characteristics of a link under test, wherein the obtained frequency domain data includes a plurality of Near-End Crosstalk (NEXT) and Common-to-Differential Near-End Crosstalk (CDNEXT) measurements;
determining, by the cable test instrument, a number of connectors in the link under test based on the obtained frequency domain data by (1) converting the obtained frequency domain data into time domain data by generating a Time Domain Crosstalk (TDX) trace signal and generating a Common-to-Differential Crosstalk (CDX) trace signal, (2) extracting attenuation distortion and dispersion distortion from the generated TDX trace signal, (3) identifying a pair of wires in the link under test, and (4) identifying a plurality of local maxima amplitude points in the CDX trace signal corresponding to the identified pair of wires;
determining, by the cable test instrument, an estimated location of each of the connectors along the length of the link under test; and
ranking the connectors in accordance with their respective contribution to detected failures in the link under test by sorting the identified plurality of local maxima amplitude points in the CDX trace signals.

2. The method of claim 1 , wherein the TDX trace signal is generated from the plurality of NEXT measurements using an inverse discrete Fourier transform.

3. The method of claim 1 , wherein determining a number of connectors further comprises calculating a threshold value adaptive to level fluctuations of noise contained in the converted time domain data.

4. The method of claim 3 , wherein calculating a threshold value further comprises calculating a composite threshold based on the level fluctuations of noise contained in the converted time domain data and based on a predetermined flat threshold value.

5. The method of claim 1 , wherein the step of determining a number of connectors further comprises:
determining a first number of connectors in a first portion of the link under test using a first cable test instrument;
determining a second number of connectors in a second portion of the link under test using a second cable test instrument; and
aligning the first number of connectors with the second number of connectors by performing a dynamic time warping (DTW) process.

6. The method of claim 1 , wherein the step of determining an estimated location comprises:
aligning estimated location of each connector in the CDX trace signal with estimated location of corresponding connector in the TDX trace signal by performing a DTW process.

7. The method of claim 1 , wherein obtaining frequency domain data comprises measuring a plurality of scattering parameters.

8. The method of claim 1 , wherein extracting attenuation distortion and dispersion distortion from the converted time domain data comprises converting bipolar crosstalk pulse responses into unipolar crosstalk pulse responses.

9. A computer-implemented method for detecting failures in electrical cabling assemblies, the method comprising:
transmitting a first test signal into a link under test by a first cable test instrument connected to a first end of the link under test and transmitting a second test signal into the link under test by a second cable test instrument connected to a second end of the link under test, wherein the first end of the link under test opposes the second end of the link under test;
obtaining, by the first and second cable test instruments, frequency domain data representing electrical characteristics of the link under test, wherein the obtained frequency domain data includes a plurality of Near-End Crosstalk (NEXT) and Common-to-Differential Near-End Crosstalk (CDNEXT) measurements;
determining, by the first cable test instrument, a number of connectors in the link under test based on the obtained frequency domain data by (1) converting the obtained frequency domain data into time domain data by generating a Time Domain Crosstalk (TDX) trace signal and generating a Common-to-Differential Crosstalk (CDX) trace signal, (2) extracting attenuation distortion and dispersion distortion from the generated TDX trace signal, (3) identifying a pair of wires in the link under test, and (4) identifying a plurality of local maxima amplitude points in the CDX trace signal corresponding to the identified pair of wires;
determining, by the first cable test instrument, an estimated location of each of the connectors along the length of the link under test;
ranking, by the first cable test instrument, the connectors in accordance with their respective contribution to detected failures in the link under test by sorting the identified plurality of local maxima amplitude points in the CDX trace signals; and
displaying, by the first cable test instrument, diagnostic information related to the link under test.

10. The method of claim 9 , wherein the TDX trace signal is generated from the plurality of NEXT measurements using an inverse discrete Fourier transform.

11. The method of claim 9 , wherein determining a number of connectors further comprises:
determining a first number of connectors in a first portion of the link under test using the first cable test instrument;
determining a second number of connectors in a second portion of the link under test using the second cable test instrument; and
aligning, by the first test instrument, the first number of connectors with the second number of connectors by performing a DTW process.

12. The method of claim 9 , wherein obtaining the plurality of CDNEXT measurements comprises generating a common mode signal on a first pair of wires on a first end of the link under test and measuring a differential mode signal on a second pair of wires on the first end of the link under test, wherein the first pair of wires is different from the second pair of wires.

13. The method of claim 9 , wherein the pair of wires in the link under test is identified by calculating signal energy value for each pair of wires in the link under test and selecting the pair having the highest signal energy value.

14. The method of claim 9 , wherein said diagnostic information includes the generated TDX trace signal and the generated CDX trace signal.

Assignees

• Fluke Corp

Inventors

• Imhof Michael

Classifications

• G01R27/28 Primary

  Measuring attenuation, gain, phase shift or derived characteristics of electric four pole networks, i.e. two-port networks; Measuring transient response (in line transmission systems H04B3/46) · CPC title

• G01R31/11 Primary

  using pulse reflection methods · CPC title

• G01R31/58

  Testing of lines, cables or conductors (testing of electric windings G01R31/72) · CPC title

• G01R31/021

  Physics · mapped topic