Abstract: Method and apparatus for determining at least one characteristic of a digital data signal. The method includes identifying at least one region of a waveform such as an Eye Diagram that contains information for determining at least one characteristic of interest of the digital data signal. Sufficient samples of the digital data signal are then taken to fully construct only the identified at least one region of the Eye Diagram without fully constructing the entire Eye diagram, and the at least one characteristic of interest is then determined from the fully constructed at least one region of the Eye Diagram.

Abstract: The present invention provides a waveform detection system and a state-monitoring system. The waveform detection system features a signal-processing function that characterizes and detects non-cyclic transient variations and performs 1/f fluctuation conversion for input waveforms to derive output waveforms. The waveform detection system characterizes signs of state variation, incorporates multiple digital filters in the digital filter calculator of the computer, uses coefficient patterns derived from non-integer n-time integration as elemental patterns for multiplication coefficient patterns, and incorporates a manner of changing the phase of at least one of the elemental patterns, input signal data, and digital filter output so that the outputs of digital filters that use the elemental patterns are synthesized in a state where a portion of the phases of the characteristic extracting and processing function is changed.

Abstract: Correlations between a residual capacity of a secondary battery and 4 parameters of an internal resistance, temperature, a discharge current and one of an open circuit voltage and a discharge voltage of the secondary battery are previously determined and a contour map of the residual capacity and 2 of the parameters is made, for example. Then, at least 2 varying parameters selected from the 4 parameters are detected while the secondary battery is in use and collated with the correlations to estimate the residual capacity of the secondary battery.

Abstract: An unusual waveform detection circuit is a digital-type unusual waveform detection circuit that arbitrarily sets a threshold used for determining an unusual waveform and produces an unusual waveform determination signal by comparing an input signal with the threshold. In producing the unusual waveform determination signal, one of a configuration where a voltage at each of all sampling points is compared with a reference voltage and a configuration where a continuously changing gradient of signal waveform peaks is calculated and is compared with a reference gradient is selectively employed. The unusual waveform detection circuit can easily and accurately detect various unusual waveforms.

Abstract: Identifying data loss in a transmission system includes shifting one of a received waveform and a transmitted waveform, determining differences between the transmitted and received waveforms at various shift points, and identifying a smallest of the differences between the transmitted and received waveforms. A plot of the differences relative to the shift points may be generated. The smallest of the differences may be a low vertex point on the plot.

Abstract: Peak capture circuitry for measuring a peak value of a waveform characterized by a first portion having a first rate of change and a second portion having a relatively faster rate of change. Peak stretching circuitry stretches a portion of the waveform as a function of time. Digital signal processing circuitry samples an output waveform of the peak stretching circuitry for determining the peak value. Thus, despite any steeply sloped portion, samples can be reliably taken throughout the waveform for calculation of peak value.

Abstract: A method of displaying a number of measurement curves is described. The measurement curves are displayed in at least two windows. Each one of the windows comprises two axes. One or more measurement curves are displayed in each one of the windows. The method comprises the steps of changing the scale of one of the curves in the direction of at least one of the two axes by a user and synchronizing at least one of the other curves of one or more other windows with respect to one of the two axes depending on said change carried out by the user.

Abstract: A method and apparatus for the characterization of optical pulses and modulators includes modulating, using a modulator, a train of optical pulses, measuring a spectrum of the modulated train of optical pulses, recording the measured spectrum as an entry in a spectrogram at a position in the spectrogram corresponding to a relative delay between the modulation and the train of optical pulses, incrementing the relative delay, and repeating the above steps until the accumulated relative delay is equal to the period of the spectrogram. The train of optical pulses and the modulator are then characterized using the measured spectra recorded in the spectrogram.

Abstract: A method and apparatus for rasterizing a digital sample stream by producing histograms for each of a plurality of time slices forming a display frame. Time slice histograms for at least one display frame are stored in a circular memory buffer and provided to a display raster for display. The first time slice displayed optionally comprises that time slice temporally associated with a trigger condition.

Abstract: A data processing system and method included within an oscilloscope for independently analyzing a signal input into the oscilloscope. The oscilloscope includes a plurality of triggering modes. A plurality of trigger parameters are specified for each of the triggering modes. Thereafter, the oscilloscope automatically analyzes the input signal, independently from any user input, utilizing each of the triggering modes and the trigger parameters specified for each of the triggering modes. The input signal includes a desired waveform and a plurality of undesired waveforms. While the oscilloscope is automatically analyzing the input signal, a determination is made regarding whether the oscilloscope triggered on one of the undesired waveforms. When it is determined that the oscilloscope triggered on one of the undesired waveforms, the undesired waveform upon which the oscilloscope triggered is stored.

Abstract: The time needed to perform an eye diagram measurement is minimized by initially randomly investigating the (X, Y)i that lie on a “starting” line crossing the sample space and expected to intersect any eye diagram. This finds a location on the eye diagram. Then the eye diagram is traversed as it is discovered by investigating nearest neighbors of locations found to belong to the eye diagram. Two arrays E and L of bits are established. The bits of E represent “eligible” (X, Y)i, while those of L represent “likely” (X, Y)i. At the very start of the measurement all bits in the eligible array E are set and all those in the likely array L are cleared, except that the starting line is established by setting in L and clearing in E locations for the corresponding (X, Y)i. Thereafter, locations in L that have 1s are measured in a randomly selected order.

Abstract: A measurement system for analyzing data values that are stored in memory and that represent a sampled electrical signal under analysis (SUA). Each of the data values represents the SUA at respective points in time over a time interval during which the SUA was sampled. The stored data values constitute a main data record. The system includes processing logic that is configured to generate at least a first reduced data record from the main data record. The first reduced data record comprises a subset of the data values of the main data record. The first reduced data record is processed by the processing logic to locate an edge (i.e., a voltage transition) in the first reduced data record. Thus, it is not necessary that the main data record, which is more voluminous than the first reduced data record, be used to locate the edge.

Abstract: A variable persistence waveform database is generated by defining a First-In-First-Out (FIFO) time-ordered queue buffer for maintaining a selected number of waveform records. Digital data samples of a measurement signal are acquired and stored in a plurality of waveform records in the FIFO time-ordered queue buffer. Counts of the digital data samples for the plurality of waveform records are accumulated in a waveform database. Upon filling FIFO time-ordered queue buffer with waveform records, the digital data samples of the oldest acquired waveform record are subtracted from the accumulated counts of the waveform database and deleted from the FIFO time-ordered queue buffer and the digital data samples of the newest acquired waveform record are stored in the FIFO time-ordered queue buffer and added to the accumulated counts in the waveform database.

Abstract: A method comprises: sampling a current waveform of an induction machine to obtain sampled points; characterizing the sampled current over a selected first time window to obtain characterized points; subtracting the characterized points from respective sampled points to obtain a residual signal comprising residual points; obtaining a frequency spectrum representative of the residual signal over a selected second time window; and identifying a rotor bar pass frequency from the frequency spectrum. The method is typically carried out by a system comprising a computer, a computer-readable medium, or combinations thereof.

Abstract: A method is described that involves forming a product waveform by multiplying a positive signal waveform and negative signal waveform. The positive signal waveform and the negative signal waveform are representative of a logical transition within a differential signal. The crossing point voltage of the logical transition within the differential signal is determined by calculating the square root of a maximum of the product waveform.

Abstract: An apparatus and method of analysis for three-dimensional (3D) physical phenomena. The physical phenomena may include any varying 3D phenomena such as time varying polar ice flows. A repesentation of the 3D phenomena is passed through a Hilbert transform to convert the data into complex form. A spatial variable is separated from the complex representation by producing a time based covariance matrix. The temporal parts of the principal components are produced by applying Singular Value Decomposition (SVD). Based on the rapidity with which the eigenvalues decay, the first 3-10 complex principal components (CPC) are selected for Empirical Mode Decomposition into intrinsic modes. The intrinsic modes produced are filtered in order to reconstruct the spatial part of the CPC. Finally, a filtered time series may be reconstructed from the first 3-10 filtered complex principal components.

Abstract: A method removes a pseudo signal from the main signal. An integrated original signal is derived by integrating the original signal with respect to time, and then, is decomposed into the sum of one Approximation and at least one Detail by wavelet transformation. The wavelet transformation is executed with deepening the level number until the level number reaches to the threshold level number at which the ratio of the energy of the one Approximation to the energy of the original signal has a predetermined relationship with a predetermined threshold value. The Approximation at the threshold level number as a pseudo signal component is approximated to zero, and the Approximation and Detail up to said threshold level number are reconstituted by wavelet inverse transformation.

Abstract: Detection error resulting from rain, detection error in the case of clear weather, and detection error in the case of rainy weather are included in measurement by a measurement unit disposed in an MW sensor system. The detection error resulting from rain sharply increases as a preset &Dgr;f becomes larger and the detection error in the case of clear weather sharply decreases as the preset &Dgr;f becomes larger. Also, using &Dgr;f as a parameter, a range in which a range where the rate of variability of the value of the detection error resulting from rain with respect to &Dgr;f is low overlaps with a range where the rate of variability of the value of the detection error in the case of clear weather is low is set as the range of the detection error in the case of rainy weather, and the value of the detection error in the case of rainy weather becomes lower than the value of the detection error in the case of clear weather.

Abstract: Signal processing techniques and systems and, in particular, an apparatus, system, algorithm and method of extraction of sinusoidal signals of time-varying nature is described. The apparatus, system, algorithm and method provide for extraction of a specified single sinusoidal component of an input signal, potentially containing other components and noise, and tracking variations of the amplitude, phase and frequency of such a sinusoid component over time. A “tool” or “core unit,” embodying the apparatus, system, algorithm or method may be used in isolation or as the fundamental building block of single-core or multi-core systems.

Abstract: Sampling techniques and circuits for a waveform measuring instrument. The sampling techniques and circuits process a series of digital signal samples through a set of sample extractors and subsequently process the extracted digital signal samples. The set of sample extractors include a uniform decimator, a low frequency dither decimator, and a digital peak detector. The uniform decimator extracts a uniform decimated sample value for each decimated sample interval in a series of decimated sample intervals. The low frequency dither decimator extracts a low frequency dither decimated (random) sample value for each decimated sample interval in a series of decimated sample intervals. The digital peak detector extracts a maximum sample value and a minimum sample value for each decimated sample interval in the series of decimated sample intervals.

Abstract: A multiple fan monitoring circuit for use with a plurality of fans, wherein each of the fans operates at a different frequency and generates a tach signal indicative of the fan operation, including a number of waveform shaping networks coupled to a corresponding one of the fans and utilized to waveshape a tach signal generated by its corresponding fan. The multiple fan monitoring circuit also includes a frequency processing circuit, coupled to the waveform shaping networks, that receives the waveshaped tach signals at a single sense node. The frequency processing circuit includes a summing circuit, coupled to the single sense node, that combines the waveshaped tach signals into a single combined signal, and a frequency discriminator, coupled to the summing circuit, that separates the single combined signal into multiple components, wherein each of the multiple components corresponds to a particular fan.

Abstract: A method of analyzing an electromagnetic interference amount of an LSI includes an equivalent impedance information calculating step of calculating and estimating equivalent impedance information based on circuit information of an LSI chip and package information of the LSI chip, and an electromagnetic interference noise calculating step of calculating an electromagnetic interference noise based on the equivalent impedance information.

Abstract: Waveform data contains waveform signals having transition events and is subdivided into data blocks. Indexing elements are provided for each waveform signal that correspond to a time range of the waveform data, and have a pointer to a data block within which transition events for the waveform signal are stored. Each indexing element has a maximum interval value that indicates the maximum amount of time spanned between transition events of the waveform signal. A minimum time resolution that may be adequately resolved on the display is computed. For indexing elements having maximum interval values that exceed the minimum time resolution, the pointers of the indexing elements are used to access and draw transition events for the waveform signals. For indexing elements having maximum interval values that are less than the minimum time resolution, a predetermined image in place of transition events for the waveform signals is drawn.

Abstract: A sampling digitizer comprises a sampling head 11, a clock generator 12, a digitizer 13 and a trigger circuit 14. A clock signal from the clock generator is also supplied to a delay element 15, and a change-over switch 16 switches from an output from the delay element 15 to a clock signal which does not pass through the delay element 15 to feed the sampling head 11 in response to a trigger signal from the trigger circuit.

Abstract: A method extracts information from a signal, the signal having properties which vary with respect to time. The signal includes a finite number of component signals, the component signals in combination defining the signal. The method analyzes the signal to determine the component signals. The signal analysis includes defining a signal analysis sample interval, the signal analysis sample interval being within a boundary, wherein at least one component signal is included within the signal analysis sample interval. The method transforms the signal over the signal analysis sample interval using a transform method to produce a transform of the signal consisting of transform coefficients. The method fits a function having real and imaginary parameters to a number of transform coefficients to determine a best fit function within the signal analysis sample interval. A mathematical operation performed on the best fit function yields parameter information within the signal analysis sample interval.

Abstract: A measurement system for analyzing data values that are stored in memory and that represent a sampled electrical signal under analysis (SUA). Each of the data values represents the SUA at respective points in time over a time interval during which the SUA was sampled. The stored data values constitute a main data record. The system includes processing logic that is configured to generate at least a first reduced data record from the main data record. The first reduced data record comprises a subset of the data values of the main data record. The first reduced data record is processed by the processing logic to locate an edge (i.e., a voltage transition) in the first reduced data record. Thus, it is not necessary that the main data record, which is more voluminous than the first reduced data record, be used to locate the edge.

Abstract: In a receiving apparatus, there are included a compensation characteristic variable type waveform degradation compensating unit capable of compensating for waveform degradation of a received signal stemming from a transmission line, a received waveform measuring unit for measuring waveform data on the received signal (which will be referred to hereinafter as “received waveform data), and a control unit for controlling a compensation characteristic of the waveform degradation compensating unit to minimize a difference between frequency data on the received signal, obtained by converting the received waveform data acquired by the received waveform measuring unit into a frequency domain, and frequency data on a reference waveform free from waveform degradation. With this configuration, certain compensation for the waveform degradation of the received signal stemming from chromatic dispersion or the like becomes feasible without using a dispersion compensation fiber.

Abstract: The prior art knows two different approaches to calibration of multichannel instruments, viz., the so-called physical and statistical calibration methods. The new methods translate the difficult inverse-problem posed by the statistical method into simpler, forward-problem, “physical” measurements of the signal and the noise. The new methods combine the quality of the statistical method with the low cost and interpretability of the physical method. The new methods disclose how to compute the optimal regression vector; how to update the optimal regression vector to account for small changes in the noise; how to choose a “good” subset of channels for measurement; and how to quantify the noise contributions from the multichannel measurement and from the reference measurement individually. The new methods are adapted to different situations to enable users in different situations to realize maximum cost savings.

Abstract: A method according to which a discrete waveform is multiplied by a sine function having an arbitrary period. The product is summed over a selected interval to derive a first summation and multiplied by a cosine function having the same period and the product is summed over the interval to provide a second summation. The sine and cosine functions are multiplied together and the product is summed over the interval to provide a third summation. The sine function is squared and summed over the interval to provide a fourth summation. Similarly, the cosine function is squared and summed over the interval to provide a fifth summation. Based on the five values, sinusoids contained in the discrete waveform are detected by subtracting each sinusoid from the discrete waveform to provide an associated residual waveform and detecting each residual waveform whose power is a local minimum as a result of varying the period.

Abstract: A noise reduction/resolution enhancement signal processing method and system is disclosed, wherein the influence of noise spikes and gaps is substantially reduced. The data for the noise reduction may be amplitudes (bx) measured at corresponding values (x) over a given domain D, wherein the data defines a composite wave form. The composite wave form is decomposed into instances of a discrete wave form, each having reduced noise amplitudes. A candidate point c in D for, e.g., an amplitude extreme is determined for each discrete wave form instance (having unknown amplitude). A minimization technique determines a first set of discrete wave form instances (having known amplitudes) by collapsing on the amplitudes (bx) from above. A maximization technique determines a second set of discrete wave form instances (having known amplitudes) by rising up to the amplitudes (bx) from below.

Abstract: A control arrangement and method is provided for detecting and responding to disturbances in electrical power systems. In a preferred arrangement, an integration is initiated that is based on a comparison of actual voltage of a source and a reference voltage. When the integration exceeds a predetermined value, the source is considered unreliable. Also in a preferred arrangement, a determination is made as to whether or not the disturbance is a downstream fault condition. For example, this is useful for applications where a transfer is made from a first source to a second source when predetermined disturbances are detected. In this manner, the transfer of the load to a second source is avoided which would continue the supply of the downstream fault. Additionally, the arrangement distinguishes between various degrees of disturbances to permit appropriate response based on the severity and type of disturbance. For example, a first immediate response, i.e.

Abstract: A waveform generating apparatus capable of outputting a desired waveform is provided. Among delay data is selected a set pulse generating delay data depending on test logical data and waveform mode information. The delay data, a skew adjusting delay data, and a fraction data in each test cycle are computed to obtain an integer delay data and a fraction delay data, which are supplied to a counter delay circuit. From the counter delay circuit are outputted a set pulse generating effective flag for delaying a test period timing by a delay time corresponding to the integer delay data, and a fraction delay data related thereto. The effective flag is delayed based on the related fraction delay data to obtain a set pulse. Similarly with the set pulse, a reset pulse is obtained, thereby to set/reset an S-R flip-flop to output a desired waveform.

Abstract: An electro-optic sampling oscilloscope (or EOS oscilloscope) uses an electro-optic probe containing an electro-optic crystal, which is placed under effect of an electric field caused by a measured signal. Laser pulses are supplied to the electro-optic crystal wherein they are subjected to polarization. Then, measurement data representative of a waveform of the measured signal are produced in response to polarization states of the laser pulses and are stored in a measurement data storage. A user can select specific measurement data by using a list of files of multiple measurement data which is displayed on a screen. Then, the EOS oscilloscope displays an outline waveform which is created based on a reduced number of sample points extracted from the selected measurement data. Comments and/or measurement conditions can be stored in the measurement data storage in relation to the measurement data, so that they are adequately displayed on the screen.

Abstract: A process for analyzing a signal which composed of a sequence of discrete amplitude values to which portions with different phase angle contribute. Here, a reshaped signal is formed in which the sequence of amplitude values is changed such that the amplitude values, or instead of them approximation values which have been brought near the amplitude values, follow one another in ascending or descending sequences according to their size.

Abstract: A system and method of measuring extinction ratio and deterministic jitter of an optical transceiver. The measurement system includes a computing node and an oscilloscope coupled to the computing node. The oscilloscope is also coupled to the optical transceiver. The oscilloscope is configured to capture a waveform of a predetermined data pattern transmitted by the optical transceiver. The oscilloscope is configured to capture the waveform in a non-persistent mode using waveform averaging. The oscilloscope is also configured to perform measurements on the waveform. The computing node is configured to program the oscilloscope to perform the measurements on the waveform. The computing node is also configured to calculate an extinction ratio and to compare the extinction ratio to an acceptable standard. The computing node is also configured to calculate a deterministic jitter value of the optical transceiver in response to the extinction ratio being within the acceptable standard.

Abstract: A method for determining the effect of load impedance on the magnitude and phase of loop gain of a power converter apparatus to aid in predicting stability of the converter apparatus under various operating conditions. The converter apparatus has an open-loop output impedance and provides an output signal to an output locus.

Abstract: A pulse management system for use by an operator that automatically performs measurements on a subset of pulses of an acquired signal stored in an acquisition memory, and generates an accessible data structure that stores characteristics of the chosen subset of acquired signal pulses, including pulse measurement results. The system searches the data structure for pulses of the acquired signal that satisfy operator-provided search criteria. In addition, the operator can sort the selected pulses in any desired manner by specifying a desired sort criteria. The system displays selected pulses along with the associated measurement results, and enables the operator to advance through the selected pulses in any mannerism to display different pulses together or separately along with the associated pulse measurement results. A method for analyzing pulses of an acquired signal is also disclosed.

Abstract: In a logic analyzer or similar binary signal-analyzing instrument, hardware circuitry, such as an ASIC, or other dedicated hardware, is used to perform waveform compression and summarization more rapidly than it could be done by software alone. The hardware is used to perform the compression of the data and to summarize its behavior for visual display. In one embodiment, the hardware starts from a given memory address and compares current timestamp values with final timestamp values to determine the length of the timeslice. Within the timeslice, all of the data is compared to determine whether it remains the same throughout the timeslice or whether it changes. The same approach can be used on violation data, such as glitches and setup and hold violations.

Abstract: The invention provides a method of analyzing a source current at a higher speed and an enhanced accuracy in a semiconductor integrated circuit including a digital circuit. The method to analyze a waveform of the source current, with consideration of re-distribution of charges throughout the digital circuit in the semiconductor integrated circuit, expressing the digital circuit with series of parasitic capacitors &Sgr;Cch,↑(nT) and &Sgr;Cch,↓(nT) to be charged and connected between the source and the ground lines. The capacitor series are calculated in time series based on the distribution of switching operations of the logic gates included in the digital circuit. An analysis model for determining the waveform of the source current in the digital circuit is obtained by connecting the parasitic capacitor series with a couple of respective parasitic impedances Zd and Zg of the source line and the ground line.

Abstract: The present invention comprises a method and apparatus that generates a waveform consisting of an arbitrary number of frequency sweeps combined from adding and subtracting mini frequency sweeps. Optimization routines determine the best combination order of frequency sweep to minimize or maximize design criteria such as aerodynamic surface deflection or maximum command rate of the wave form. The invention allows for arbitrary output timing, or commands per second issued for the desired waveform, arbitrary starting and ending frequencies and amplitudes, arbitrary number of frequency sweep components, arbitrary frequency sweep exponent, arbitrary amplitude sweep exponent, and arbitrary waveform length. For a given frequency range and sweep exponent, amplitude range and sweep exponent, desired total waveform time and number of frequency sweep components, the algorithm can determine the optimum arrangement of the components to minimize the maximum amplitude or rate.

Abstract: A method, a circuit arrangement and an apparatus are provided for evaluating an input data signal transmitted by load modulation. A complex data signal is derived from the input data and a mean value signal of the complex data signal is thereafter derived. A complex signal without mean value is also formed from the difference between the complex data signal and the mean value signal of the complex data signal. A first and second quadratic error signals are derived and subsequently a slope signal is derived from the first and second quadratic signals. The method also comprises deriving an information signal by comparing the imaginary part signal without mean value with a decision threshold signal. The information signal indicates whether a value of the input data signal has been generated in a loaded state or an unloaded state during the load modulation.

Abstract: A signal transfer device measurement system and method of the present invention measures the signal transfer characteristics of a device under test (DUT) having an analog input port and either an analog output port or a digital output port. The measurement system and method comprise a stimulus waveform generator that produces a stimulus waveform. The stimulus waveform comprises a time sequence of pairs of narrow bandwidth, modulated signals. The stimulus waveform is applied to the input port of the DUT thereby producing an output response signal at the output port of the DUT. For a DUT with an analog output port, the measurement system and method further comprise an analog-to-digital converter (ADC) for digitizing the output response signal and producing digital data and a signal processor for processing the digital data thereby producing measured results.

Abstract: An improved method for non-harmonic waveform analysis that permits freedom of selecting intervals and/or frequencies (or periods) for analysis is disclosed. An arbitrary interval of a discrete waveform is multiplied by a sine function having an arbitrary period and the product is summed over the interval to derive a first summation. Similarly, the waveform is multiplied by a cosine function having the same period and the product is summed over the interval to provide a second summation. The sine and cosine functions are multiplied together and the product is summed over the interval to provide a third summation. The sine function is squared and summed over the interval to provide a fourth summation. Similarly, the cosine function is squared and summed over the interval to provide a fifth summation.

Abstract: An automatic save and recall system and method for use in signal measurement systems that acquire and store signal data in accordance with a trigger specification, including generally a trigger definition and trigger control parameters (“trigger controls”). The present invention automatically stores in memory (“saves”) trigger-related data that includes, for example, a current trigger definition and other specified portions of a trigger specification (“saved trigger specifications”) without an explicit operator request. A plurality of such saved trigger specifications are subsequently available for retrieval from memory (“recall”). This enables an operator to easily return to a previous version of a trigger definition should the operator determine that a current trigger definition is undesirable. The automatic storing of trigger specifications (or portions thereof) may occur in response to one or more predetermined event(s).

Abstract: A method of determining peaks in a discrete function. The method comprising the steps of: applying a closing function to the discrete function to generate a closed discrete function; defining peaks within the closed discrete function; sorting the defined peaks according to function value; and applying a threshold value to each sorted defined peak in individual succession, wherein sorted defined peaks having a peak height value above the threshold value are retained within the closed discrete function.

Abstract: A method employed in a condition monitoring unit (CMU) for monitoring a circuit breaker or interrupter to obtain a substantially undistorted version of a waveform suffering from saturation distortion comprises employing a current transformer (CT) to measure a current waveform. The output of the CT is prone to be a partially distorted waveform. The invention is generic in the sense that it does not require parameters associated with the CT characteristics or with the burden impedance on the secondary side of the CT. A digital representation of the partially distorted waveform is obtained, and then undistorted portions of the partially distorted waveform are identified by comparing the amplitude of the partially distorted waveform within a sliding window to a pair of boundary values and identifying as undistorted those portions having an amplitude between the boundary values. Next, distorted portions of the waveform are separated from the undistorted portions, thereby yielding a data record with holes.

Abstract: For the purpose of detecting signals by means of fuzzy-logic classification, these signals are sampled in time and the sampled values are compared with fuzzy threshold values with the aid of fuzzy-logic rules. Strengths which evaluate the similarity of the signal to be detected with the relevant master signal given the application of the relevant rule are determined for each master signal of a signal catalog. Furthermore, a membership is calculated for each master signal as the arithmetic mean of all the strengths, averaged over all the rules, and the signal to be detected is assigned to that master signal whose membership is a maximum.