Tektronix, Inc.

Michael S Overton

Barry A McKibben

Daniel G Baker

Scott E Zink

Michael D Nakamura

Evan Albright

Thomas E Chabreck

Xinyu Zhu

Bruce J Penney

Florian Gene Bell

Glenn Bateman

Kevin Thomas Ivers

Douglas C Stevens

Gilbert A Hoffman

William A Trent

Robert W Parish

Richard I Lane

Robert D Kluser

Dennis L Holmbo

Laurent A Melling, Jr

Kevin B McDonald

Edward D Wardzala

Barry L Rosenow

Robert Davies

Scott A Johnson

Benjamin T Humble

Wendelyn Gavett

Alan E Mathieu

Francis Iannacci

Oke Tammik

Laurent A Melling Jr

Embodiments of the invention are directed to a system for generating video test pattern signals from definitions contained in a text-based definition file. The definition file allows the user to create generic definitions for test signals that can be interpreted to create test signals in a variety of formats, raster sizes, color spaces, sample structures, frame modes, and bit depths. A parametric generator uses one or more engines to then generate the desired test pattern from the definition file.

System for generating text defined test patterns

Embodiments of the invention include a test and measurement device, system, and method for synchronizing measurement views and configuration parameters across multiple input channels or devices. A method includes receiving signals under test associated with multiple input channels of the test and measurement instrument or with multiple devices, selecting a measurement view of one input signal or device, receiving a synchronized view enable preference from a user control interface, and synchronizing the measurement view or configuration parameters of the other signals or devices with what was chosen on the first signal or device. A test and measurement instrument includes input terminals to receive the input signals, a user control interface to receive input from an operator, a display to provide measurement information about the input signals, and a synchronization control unit to synchronize measurement views and/or configuration parameters between the inputs or devices.

Test and measurement device, system, and method for providing synchronized measurement views

A relay fault detection and correction system includes a signal detector structured to measure primary and secondary signals, and generates a fault output signal if the signals appear to be unterminated due to a relay not connecting the signals to the loads. A cycle circuit is structured to cause a relay controller to cycle a potentially under-performing relay between its states a number of times after the signal detector generates the fault output.

Relay failure detection system

Front panel for rack mounted video device

A video timing display for multi-rate systems allows a user to quickly, easily and precisely measure the timing difference between video signals of different rates. A graphic display area within a raster display region provides a display of vertical and horizontal timing offsets of one video signal with respect to another video signal as a reference having a different frame rate. The graphic display area includes a reference indicator associated with the reference and timing indicators indicating the timing phases between the video signals, with one of the timing indicators being emphasized. A numeric display area may be provided adjacent the graphic display area to display the actual vertical and horizontal timing differences in appropriate units for the emphasized timing indicator relative to the reference indicator with a precision to one video clock cycle.

Video timing display for multi-rate systems

A flexible timebase for eye diagrams uses a stable free running oscillator as a sample clock for equivalent time sampling of an input serial digital signal and of a reference signal, derived from a subdivided recovered clock of the input serial digital signal. The reference signal samples are provided to a digital phase-locked loop that provides the flexible timebase to an eye pattern generator. The eye pattern generator accumulates the input serial digital signal samples at times corresponding to the reference signal samples to produce the eye diagram. A linear phase detector in the digital phase locked loop converts the reference signal samples to a complex signal using a Hilbert transform and then to a linear ramp of phase values using a CORDIC algorithm with arctangent lookup table. A subtractor then subtracts the digital phase-locked loop feedback from the linear ramp to provide the input to the loop filter.

Flexible timebase for eye diagram

A flexible timebase for eye diagrams uses a stable free running oscillator as a sample clock for equivalent time sampling of an input serial digital signal and of a reference signal derived from a subdivided recovered clock of the input serial digital signal. The reference signal samples are provided to a digital phase-locked loop that provides the flexible timebase to an eye pattern generator. The eye pattern generator accumulates the input serial digital signal samples at times corresponding to the reference signal samples to produce the eye diagram. A linear phase detector in the digital phase locked loop converts the reference signal samples to a complex signal using a Hilbert transform and then to a linear ramp of phase values using a CORDIC algorithm with arctangent lookup table. The digital phase-locked loop feedback is subtracted from the linear ramp to provide the input to the loop filter.

Flexible timebase for EYE diagram

Aspects of the present invention are related, in general, to Type-III phase-locked loops. In particular, aspects of the present invention relate to analog Type-III phase-locked loop arrangements comprising at least two signal paths, wherein each signal path may correspond to a bandwidth partition and may be selected by a selector according to a bandwidth parameter value. According to one aspect of the present invention, a first signal path may correspond to a fast loop (wide closed-loop bandwidth), and a second signal path may correspond to a slow loop (narrow closed-loop bandwidth).

Analog phase-locked loop

A luminance qualified vector display device provides a vector display that is gated by a specified luminance range. In one implementation three luminance gates may be used, one for luminance levels above a specified high luminance threshold, a second for luminance levels below a specified low luminance threshold, and a third for luminance levels between the specified high and low luminance thresholds. Also the luminance thresholds for the medium luminance range may be separately adjusted to overlap the high and low luminance ranges respectively. Each luminance qualified vector display may be displayed separately, may be overlaid for display using a different color for each luminance range, or may be displayed in different quadrants of a display device or window together with the normal, non-luminance qualified, vector display.

Luminance qualified vector display

A two-dimensional video timing display with numeric readouts allows a user to quickly, easily and precisely measure the timing difference between video signals. A graphic display area within a raster display region provides a two-dimensional display of vertical timing offset and horizontal timing offset of an input video signal with respect to a reference video signal, the graphic display area including a reference indicator centered in the graphic area indicating the timing of the reference video signal and a timing indicator in the graphic area indicating the timing of the input video signal with respect to the reference video signal. A numeric display area is adjacent the graphic display area to display the actual vertical and horizontal timing offsets in appropriate units according to the format of the input video signal with a precision to one video clock cycle. Also the source of the reference video signal and optionally an alarm when the timing between the two video signals is outside predetermined limits may be shown in the numeric display area. For an instrument having a tiled raster display a vector display may be shown in conjunction with the timing display to provide fine subcarrier phase discrimination between analog composite video signals for hue matching.

Two-dimensional video timing display

An apparatus and method for controlling and detecting the alignment of a color frame phase from a composite analog video signal decodes the composite analog video signal to produce a component digital video signal and to generate a color frame signal that represents the start of each color frame for the composite analog video signal. Based upon the color frame signal a flag signal is inserted into the component digital video signal. The component digital video signal is captured by an analyzer based upon the flag signal so that the captured component digital video signal is in color frame phase with a stored reference component digital video signal. Preferably the stored reference component digital video signal represents a test sequence having an integer number of color frames plus or minus one video frame.

Controlling and detecting alignment of composite video color frames

Alignment of two video sequences, one being a reference video sequence and the other being a processed video sequence corresponding to the reference video sequence, is performed using selected partial pictures from the reference video sequence. The reference video sequence is evaluated for portions that have maximum information content spatially and/or temporally to select the partial pictures, and the location and size of the partial pictures are stored together with the reference video sequence. The processed video sequence is then initially aligned to the reference video sequence by first finding the locations of features from the partial pictures in the processed video sequence to provide a coarse misalignment error between the two video sequence, and then using a correlation algorithm with a scanning window based on the size of the partial pictures to refine the misalignment error. Once the processed video sequence is aligned with the reference video sequence by using the refined misalignment error, measurement of the differences between the two sequences may be obtained as an indication of the amount of degradation of the processed video sequence with respect to the reference video sequence.

Video alignment using a selected partial picture

A three-dimensional test signal for a video codec is generated by injecting a conventional foreground test signal at a predetermined location as a foreground component within a background test signal as a background component, the background component having a variable complexity. The three-dimensional test signal is input to the video codec and the output of the video codec is measured using conventional measurement instruments. The background component may be a pseudo-random noise signal, a zone plate signal or other variable complexity-type signal, with the foreground component occurring at greater intervals than the neighboring pixels used by the codec compression algorithm. The conventional measurement instruments display only the foreground component with distortions in the video codec caused by the complexity of the background component appearing in the display. A spectral display of the output of the video codec using a zone plate signal as the background component may also be used to characterize the video codec performance.

Three-dimensional testing of video codes

An edge integrating phase detector for a phase locked loop passes a portion of a sync edge of an input video signal as a sampled signal to an integrator in response to a gate pulse nominally centered on a timing reference point of the sync edge. The sampled signal has a positive and negative portion. The integrator produces from the sampled signal a control signal for a VCO that is proportional to the unbalance between the positive and negative portions. The gate pulse is generated from the output of the VCO as a function of the nominal period of the input video signal.

Edge integrating phase detector

A method for examining a propagative medium, such as a signal transmission cable, that requires the acquisition and examination of a minimum number of data points to determine the presence of an anomaly in the medium. When an anomaly is detected, its characteristics, such as loation, type and amount of loss are determined. The characteristics are then displayed. If the anomaly is a reflectionless loss, the region containing the anomaly is examined repetitively to determine its location and to improve the accuracy of its location measurement. With each successive level of examination, additional samples are collected within the region. The new samples are combined with the existing samples to reduce random noise in the data. Through this method the location of the anomaly is re-determined with greater accuracy.

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Beaverton, OR, United States of America

Michael S Overton