Abstract: A test and measurement instrument processes digital data that represents an input signal to produce a target image, and then uses a computer vision technique to recognize a signal depicted within the target image. In some embodiments, the location of the signal within the target image is identified on a display device. In other embodiments, the location of the signal within the target image is used to perform a measurement. In other embodiments, when the signal is recognized, a trigger signal is generated that causes digital data that represents the input signal to be stored in a memory.

Abstract: A fast rasterizer uses a fast memory that has a bit-set port for receiving data and a totally independent readout and clear port for outputting a waveform image. The fast memory is organized into rows and columns corresponding to the rows and columns of a raster display device, with each memory location or cell holding a single bit. The fast memory is divided into parallel sections so that one column of each section may be written into each clock cycle, resulting in the possibility of writing a plurality of columns into the fast memory each clock cycle. Each memory cell is set when a row and column write signal for the cell are asserted, and is read out and cleared when a row and column read signal for the cell are asserted. Row logic using thermometer codes is used to set the row lines for the selected column in each section.

Abstract: A frequency mask trigger capable of triggering based on a logical combination of two or more areas of a frequency mask transforms a frame of digital data representing an input signal into a frequency spectrum having a plurality of frequency bins, with each frequency bin having a power amplitude value. A frequency mask is defined having a plurality of reference power levels, one reference power level being associated with each frequency bin. Two or more areas of the frequency mask are defined, with each mask area corresponding to one or more of the frequency bins. A violation status is determined for each mask area by comparing all of the power amplitude values within each mask area to the associated reference power level. If any of the power amplitude values within the mask area violates the associated reference power level, then the entire mask area is deemed to be violated. A trigger signal is generated when a logical combination of the violation statuses of the mask areas is satisfied.

Abstract: A test and measurement instrument converts digital data that represents an input signal into a plurality of bitmaps, and then subtracts one of the bitmaps from another one of the bitmaps to produce a difference bitmap. The difference bitmap does not contain density values that are common to the two bitmaps, but instead only contains the density differences between the two, thereby revealing very small density variations in the presence of large density values. In some embodiments, the difference bitmap is displayed on a display device. In other embodiments, the difference bitmap is used to generate a trigger signal.

Abstract: 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, such as a sine wave, 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 is then used to subtract the digital phase-locked loop feedback from the linear ramp to provide the input to the loop filter.

Abstract: A method of correcting the frequency response of an RF receiver having a frequency translation device and a fixed IF frequency section uses calibration data representing frequency responses over a wide frequency range for multiple center frequencies. The calibration data are based upon a multi-dimensional model for the frequency translation device that includes at least center frequency and offset frequency. The calibration data are stored in the RF receiver during factory calibration. A run-time normalization of the RF receiver produces a normalization frequency response at a reference frequency, and a relative frequency response at a desired center frequency is derived from the calibration data. The normalized and relative frequency responses are combined to produce an overall frequency response that is used by the RF receiver to configure an inverse filter to correct channel linear distortion produced by the frequency response of the frequency translation device at the desired center frequency.

Abstract: A realtime display compression for a waveform image uses a priority basis for combining groups of pixels when producing a compressed waveform image in order to preserve intensity information. As an example successive lines of data for the waveform image are demultiplexed into line buffers in a circulating manner, the number of line buffers being a function of the maximum desired integer compression ratio. The outputs from the line buffers are aligned and the corresponding pixels are combined according to a desired compression ratio, one output line for each integer compression ratio. The appropriate compressed line is selected as the output line according to the desired compression ratio, with the totality of the output lines forming the compressed waveform image.

Abstract: A video test system is provided with a circular buffer to capture a video input sequence in response to a trigger, and a test generator output to generate a video test sequence based upon the captured video test sequence. The system may be implemented using a single instrument, or a combination of instruments, such as video waveform monitors and video signal generators. A method is also provided for generating video test sequences based upon captured video sequences.

Abstract: The method of processing waveform data from one or more channels using a test and measurement instrument, such as an oscilloscope, is described in which waveform data is collected from a DUT; defining a context is defined by instructing the instrument to obtain the focus of each waveform datum having a first user-defined attribute; defining a selection criteria by instructing the instrument to obtain the focus of each waveform datum having both a first user-defined attribute and a second user-defined attribute; and defining an action by instructing the instrument to perform an operation responsive to finding at least one waveform datum having both the first user-defined attribute and the second user-defined attribute.

Abstract: A test and measurement instrument includes a pattern detector for detecting a beginning sequence in a signal under test (SUT), and generates a synchronization signal. In response to the synchronization signal, a memory outputs a reference test pattern. A symbol comparator compares the reference test pattern with the SUT. The symbol comparator can produce a symbol error rate. One or more 8b to 10b converters receives the SUT from the input and the digitized data from the memory, and converts the data from an 8b coded format to a 10b coded format. A bit comparator compares the 10b coded reference test pattern with the 10b coded SUT in response to the symbol comparator. The bit comparator is coupled to a bit error counter, which produces a bit error rate independent of any disparity errors that may be present in the incoming digitized data received by the test and measurement instrument.

Abstract: A system and method for detecting channels in a network using messages passing through the network is provided. An embodiment comprises detecting AAL2 channels communicating between a Node B and an radio network controller and also between two radio network controllers. In the case of communication between a NodeB and a radio network controller, the AAL2 channels are detected by matching pairs of Random Access Channel (RACH) and Forward Access Channel (FACH) associated with a user equipment identity along with a Dedicated Channel (DCH) until the AAL2 channels present between the Node B and the RNC are determined to a desired level of confidence. In the case of communication between two radio network controllers, only the DCH channels need to be detected to completely detect the AAL2 channels.

Abstract: Pre-trigger and post-trigger acquisition for a no dead time acquisition system, where the data being displayed does not include a related trigger event, has a variable record length buffer having a maximum record length equal to a maximum desired pre-trigger interval, and has a trigger FIFO and timer for delaying the related trigger event. The record length of the buffer is determined by the desired pre-trigger interval, and fast rasterizers access the oldest data that encompasses the desired pre-trigger data. A first trigger event in the trigger signal may be delayed by a desired post-trigger interval before the fast rasterizers begin drawing the waveform data that encompasses the desired post-trigger data.

Abstract: An arbitrary waveform generator converts digital waveform data stored in a memory into an analog output signal by using a digital-to-analog converter. In order to make the frequency characteristics of the output signal flat, the created digital waveform data is modified in accordance with a predetermined S-parameter of the arbitrary waveform generator, and the modified digital waveform data is stored in the memory for generating the analog signal having the compensated frequency characteristics.

Abstract: Picture quality measurement systems and methods are provided for measuring DC blockiness within video blocks. Block boundaries are located within a test video frame. The relative AC differences within each block are measured using a reference video frame, a statistically estimated reference or a default value of the white video level divided by two. An objective DC blockiness map, a subjective DC blockiness map or both may be generated.

Abstract: The resistive probing tip system has one or more carriers and one or more electrical contact assemblies. Each carrier has opposing surfaces with a plurality of resistors engaging the carrier. Each of the plurality of resistors has opposing electrical contacts that are exposed at respective opposing surfaces of the carrier. Each electrical contact assembly has opposing surfaces with electrical contacts exposed at the opposing surfaces with each electrical contact exposed on one surface coupled to a corresponding electrical contact on the other opposing surface. The carrier(s) and the electrical contact assembly(s) selectively mate to and mate from one another with the electrical contacts exposed at the opposing surfaces the carrier(s) and the electrical contact assembly(s) contacting one another. The carrier(s) and/or the electrical contact assembly(s) may be selectively secured to either of a circuit board or a probe head.

Abstract: 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.

Abstract: A shielded signal pass-through or via structure integral with an electronic circuit board is described. The structure includes a rigid inner generally cylindrical conductor; at least a semi-rigid intermediate annular dielectric surrounding the conductor; and a rigid outer annular conductor surrounding the dielectric material. Also described is an interconnect device that presents a contact array in a boss region of a unitary embossed printed circuit board (PCB) optionally equipped with one or more such shielded vias.

Abstract: Logic analyzers and real-time spectrum analyzers use real-time statistical processes as a basis for creating a trigger. The statistical displays within a test and measurement system such as a Logic Analyzer (LA) or Spectrum Analyzer (SA) or other instrument are used in a user interface to define a trigger based on the statistical event itself. In brief, the invention is a Real Time Statistical trigger established by the user through a direct interaction with the Real Time Statistics displays. This interaction can be via a graphical user interface, or the user interface can employ a non-visible display (e.g., a speaker) or input device (e.g., a microphone).

Abstract: A signal generating device has a display and a central processing unit for setting parameters for a serial data pattern and parameters for deterministic and random jitter impairments, and a displacement crest factor emulation impairment to be applied to the serial data pattern. A waveform record file is generated using the serial data pattern parameters, the impairment parameters for the deterministic jitter and random jitter, and the displacement crest factor emulation impairment. The displacement crest factor emulation impairment is selectively positioned in the impaired serial data pattern. A waveform generation circuit receives the waveform record file and generates an impaired serial data pattern analog output signal based on the serial data pattern, deterministic and random jitter impairments, and the displacement crest factor emulation impairment with the displacement crest factor emulation impairment being selectively positioned in the impaired serial data pattern analog output signal.

Abstract: A real-time trigger figure-of-merit indicator for test and measurement instruments provides an indication of how close a signal-under-test is to satisfying a relevant trigger condition. The indicator includes a first marker that indicates a real-time trigger figure-of-merit that is calculated based on digital samples that represent the signal-under-test, and a second marker that indicates a level that the figure-of-merit must exceed in order for a trigger event detector to detect a trigger event and generate a trigger signal. Thus, by observing the indicator, a user may easily ascertain how close a signal-under-test is to satisfying the relevant trigger condition without requiring the instrument to actually trigger.