A test and measurement instrument includes an input configured to receive a signal for testing, an acquisition processor configured to generate an acquisition from the received signal and store the acquisition in an acquisition memory, and copy the acquisition to a data store, and an acquisition evaluator configured to compare the selected acquisition in the data store against one or more criteria, and identify whether the acquisition meets the one or more criteria. When the acquisition meets the one or more criteria, the acquisition may be stored in a secondary memory of the instrument as a curated or selected history of measurements, on which measurements or other analysis may be made.

This disclosure relates generally to test and measurement instruments structured to detect that a series of events occurred, and structured to generate a trigger signal in response to detecting that a final event in the series of events occurred. The trigger may be generated based on a timeout signal, or based on another event, trigger, or signal. Stored data in the acquisition memory may be marked relative to the detection of the final event. An external forced timeout signal may control which in a series of events is marked as a final event. The triggering on final event may be enabled after another trigger is satisfied, and may be used as one of many different types of triggers.

A trigger method for triggering a measurement device on a signal pattern in a signal is provided. The trigger method comprises the steps of receiving the signal pattern, receiving the signal, computing a first cross-correlation of the signal pattern and the signal, and triggering the measuring device, based upon the first cross-correlation.

The present disclosure provides a main measurement device for simultaneously measuring signals with at least one secondary measurement device, the main measurement device comprising a reference signal output port configured to couple to the at least one secondary measurement device, a reference signal generator coupled to the reference signal output port and configured to generate a reference signal, a measurement port configured to receive a signal to be measured, a trigger output port configured to couple to a trigger input port of the at least one secondary measurement device and to output a trigger signal, and a controllably switchable internal signal path configured to selectively couple the reference signal generator with the measurement port. Further, the present invention discloses a respective secondary measurement device, a respective measurement system, and a respective method.

The disclosure relates to a test and measurement instrument. The test and measurement instrument comprises a digitizer for digitizing an analog input signal, thereby generating a digitized input signal. The test and measurement instrument also has a digital trigger for detecting a trigger event in the digitized input signal. The test and measurement instrument also comprises an acquisition memory for acquiring the digitized input signal at least segmentally upon a first trigger event detected by the digital trigger. The acquisition memory is configured to acquire a first signal segment prior to the first trigger event. The acquisition memory is further configured to acquire a second signal segment starting at the first trigger event. The length of the second signal segment is dynamically adjustable. Moreover, a method of analyzing an input signal by a test and measurement instrument is described.

A sampling oscilloscope includes a trigger generation circuit that includes a direct digital synthesizer (DDS) that outputs a trigger clock input in an operable frequency range at an arbitrary output frequency, a band pass filter (BPF) that limits a pass band of the trigger clock output from the direct digital synthesizer and a variable frequency divider that divides a frequency of the trigger clock of which the pass band is limited by the band pass filter, and generates a strobe signal of a frequency at which a sampler can be operated. The sampling oscilloscope includes a controller that calculates a phase shift amount with reference to a pattern cycle of data generated by a one-time strobe signal and adjusts a phase by changing a count value of a phase accumulator of the direct digital synthesizer so that the calculated phase shift amount is eliminated.

The invention relates to a method for determining a time of a flank in a signal, wherein the method comprises a step of reading the signal and has a master clock rate for operating a digital evaluation unit for evaluating the time of the flank. The method also comprises a step of forming a data word representing the signal, using a deserializer of a SERDES cell, wherein the data word has a plurality of bits, and wherein a sampling clock rate is applied to the SERDES cell for sampling the signal, which sampling clock rate is higher than the master clock rate, wherein one flank or two flanks of the sampling clock rate are used for sampling the signal. Finally, the method comprises a step of determining the time of the flank in the signal using the data word and the master clock rate in the evaluation unit.

A system includes a plurality of oscilloscopes, each oscilloscope having an output port and an input port, a cable connecting the output port of an initial oscilloscope of the plurality of oscilloscopes to the input port of a second oscilloscope of the plurality of oscilloscopes, the initial oscilloscope having a processing element to generate a master run clock, the second oscilloscope having a processing element including a phase-locked loop to lock a slave run clock to the master run clock, wherein the processing element of one of the oscilloscopes executes code to cause the processing element to manipulate one of the run clocks to pass trigger information to another of the plurality of oscilloscopes. A method of synchronizing at least two oscilloscopes including a master oscilloscope and at least one slave oscilloscope includes connecting the at least two oscilloscopes together using output ports and input ports of the at least two oscilloscopes and at least one cable; sending a master run clock from the master oscilloscope to at least one slave oscilloscope; synchronizing a run clock of the at least one slave oscilloscope to the master run clock; recognizing a trigger event at a first oscilloscope of the at least two oscilloscopes; altering the run clock at the first oscilloscope to encode a trigger indication; and receiving the altered run clock at a second oscilloscope of the at least two oscilloscopes, wherein the trigger indication causes the second oscilloscope to recognize the trigger event.

A method, system, and computer program product for detecting and monitoring a signal is provided. The method includes detecting an alignment point for a periodic signal segment of a periodic signal generated by an apparatus being monitored for standard functionality In response, the apparatus is activated from a period prior to the alignment point to an end point of the periodic signal segment and a first point of the periodic signal segment is located. Likewise, a second point of an additional periodic signal segment of the periodic signal is located. The periodic signal is normalized based on results of locating the first point and the second point.

An oscilloscope comprises a processing module or circuit and at least a first channel and a second channel. The first channel comprises a digitizer configured to receive an analog input signal and to provide a time and amplitude discrete representation of the input signal to the processing module. The second channel comprises a phase digitizer configured to receive a reference signal and to provide a time discrete representation of the phase of the reference signal to the processing module. The processing module is configured to process both the time and amplitude discrete representation of the input signal and the time discrete representation of the face of the reference signal.