Darrell R Johnson

US Patent:

6434716, Aug 13, 2002

Filed:

Jan 29, 1999

Appl. No.:

09/240154

Inventors:

Darrell J. Johnson - La Mesa CA
John C. McCosh - San Diego CA

Assignee:

Psiber Data Systems Inc. - La Mesa CA

International Classification:

G01R 3128

US Classification:

714712, 714714, 714715, 709223, 709224, 370213, 370465

Abstract:

A network link tester couples to a LAN port with the LAN port having both a network transmit pair and a node transmit pair line. The link detector scans the network transmit pair and node transmit pair lines for the presence of link signals. Upon finding a link signal, the link tester indicates if the link signals were on the network transmit pair or on the node transmit pair line. Further, the link tester determines the network standard used and identifies the available operational nodes. The process of using a LAN tester includes coupling the tester to the LAN port, scanning network lines for the presence of link signals and determining and displaying operational capabilities. Optionally, the link tester may generate a tone signal on the network lines to assist in identifying line faults. Further, the link tester may generate link signals responsive to receive link signals.

US Patent:

6707305, Mar 16, 2004

Filed:

Oct 16, 2001

Appl. No.:

09/978910

Inventors:

Darrell J. Johnson - La Mesa CA
John C. McCosh - San Diego CA

Assignee:

Psiber Data Systems Inc. - La Mesa CA

International Classification:

H04B 346

US Classification:

324542, 324539

Abstract:

The tone generator uses a highly accurate frequency signal to generate an accurate and stable tone signal. A cadence pattern may be used to output the tone signal onto a test cable in an easily distinguishable pattern. The tone signal may be selectively output at an in-band band frequency or an out-band frequency. A corresponding tone probe may be used to detect the tone signal. The tone probe uses a high-Q bandpass filter to reject all but the expected frequency of the tone signal. The signal passing the bandpass filter is proportional to the detected tone signal. The tone probe generates an audio signal unrelated to the frequency of the tone signal. The audio signal is modulated by the signal from the bandpass filter, and then broadcast through a speaker. Accordingly, the tone probe provides an audible sound proportional to the strength of the tone signal, but is unrelated in frequency.

US Patent:

7116093, Oct 3, 2006

Filed:

Jan 30, 2004

Appl. No.:

10/768470

Inventors:

Darrell J. Johnson - La Mesa CA, US
John C. McCosh - San Diego CA, US

Assignee:

Psibor Data Systems, Inc. - La Mesa CA

International Classification:

G01R 23/167
G01R 19/00

US Classification:

324 7628, 324 66, 379 25

Abstract:

The tone generator uses a highly accurate frequency signal to generate an accurate and stable tone signal. A cadence pattern may be used to output the tone signal onto a test cable in an easily distinguishable pattern. The tone signal may be selectively output at an in-band band frequency or an out-band frequency. A corresponding tone probe may be used to detect the tone signal. The tone probe uses a high-Q bandpass filter to reject all but the expected frequency of the tone signal. The signal passing the bandpass filter is proportional to the detected tone signal. The tone probe generates an audio signal unrelated to the frequency of the tone signal. The audio signal is modulated by the signal from the bandpass filter, and then broadcast through a speaker. Accordingly, the tone probe provides an audible sound proportional to the strength of the tone signal, but is unrelated in frequency.

US Patent:

20030204611, Oct 30, 2003

Filed:

Apr 29, 2002

Appl. No.:

10/134417

Inventors:

John McCosh - San Diego CA, US
Darrell Johnson - La Mesa CA, US

International Classification:

G06F015/16

US Classification:

709/230000

Abstract:

A portable and handheld communications tester is provided. The communications tester conveniently simulates a DHCP client for establishing communication with a DHCP server. Accordingly, the communications tester exchanges standardized DHCP messages with the server to be assigned a dynamic IP address. The communications tester thereby verifies operational connectivity with the DHCP server. The communications tester may be arranged with particular physical connectors for connecting to Ethernet, DSL, fiber optic, and/or coaxial cables. Further, the communications tester may have an optional integral modem for providing modulation and demodulation on the communication cable. In a particular example of the communications tester, the communications tester also incorporates a PING function for interrogating IP devices along the communication link. The tester may also employ BERT, Stress and other testing functions to further characterize and verify the robustness of the communication connection. Conveniently, the communications tester may be provided as a standalone device, or may be integrated into existing portable test equipment.

US Patent:

20130162262, Jun 27, 2013

Filed:

Jun 17, 2012

Appl. No.:

13/525333

Inventors:

Darrell J. Johnson - La Mesa CA, US
John C. McCosh - San Diego CA, US
Sara Marmolejo - Austin TX, US

International Classification:

G01R 31/02

US Classification:

324539

Abstract:

Briefly, a method and system for testing a cable harness is disclosed. Generally, a cable harness is used to route many electric wires for power, communication, and control. The tester includes a switch system that enables one or more TDR engines to sequentially apply a TDR stimulus to substantially all the wire pairs in the cable harness, and to collect the resulting TDR waveforms. The waveforms are analyzed to determine if the cable harness meets quality standards. In some cases the tester may also perform a continuity, resistance, capacitance, or inductance test on the cable harness. The tester may also measure and use temperature in analyzing the cable harness, or may apply temperature cycling, different or varying atmospheric pressures, vibration, shaking, or shock to the cable harness.

US Patent:

61148474, Sep 5, 2000

Filed:

Oct 4, 1995

Appl. No.:

8/538639

Inventors:

Darrell Johnson - La Mesa CA

International Classification:

G01R 122

US Classification:

324127

Abstract:

A connectionless signal detection device for conductive cables contains one or more bifurcated, wire-wrapped magnetic core assemblies positioned axially in an elongated alignment channel, allowing the device to accurately detect the transmission of signals or information on conductive cables using an inductive method. Each assembly section of the magnetic core assembly is wrapped with a conducting wire, with opposed assembly sections electrically connected in a bucking configuration, that is, the output side of one assembly section is connected to the output side of the opposing assembly section. The assembly sections either mate directly at their intersections or alternately operate with a dual gap. The elongated alignment channel opens and closes to allow positioning of the magnetic core assemblies concentrically about a conductive cable. The device operates in a connectionless mode and so is able to detect and monitor data transmission without physical, electrical, or logical interference to the conductive cable.

US Patent:

20170023632, Jan 26, 2017

Filed:

Feb 1, 2016

Appl. No.:

15/012237

Inventors:

Darrell J. Johnson - La Mesa CA, US
John C. McCosh - San Diego CA, US
Sara Johnson - La Mesa CA, US

Assignee:

Psiber Data Systems, Inc. - San Diego CA

International Classification:

G01R 31/11
G01R 27/06
H03L 7/08
G01R 31/02

Abstract:

Briefly, a method and system is provided for testing a cable using a high performance Time Domain Reflectometry (TRD) system and method. The TDR has a timing generator that is constructed to generate a periodic launch pulse to excite a cable under test, and to generate sample signals that are time delayed from the launch pulse. The timing for the launch pulse and the sample signal may be defined by two correlated PLL circuits coupled to the same clock. In one implementation, the timing generator is constructed in a single FPGA. The invention also provides calibration circuitry to compensate for temperature, voltage, and manufacturing variations in the FPGA. In one example, a tester includes a switch system that enables one or more TDR engines to sequentially apply a TDR stimulus to substantially all the wire pairs in a cable harness, and to collect the resulting TDR waveforms. The waveforms are analyzed to determine if the cable harness meets quality standards.