Oscilloscope Search Tool Finds Faults Fast

Oct 1, 2006 12:00 PM
By David Morrison, Editor, Power Electronics Technology

Click here for the enhanced PDF version of this article includes diagrams and/or equations.

The latest additions to LeCroy's WaveRunner Xi and WaveSurfer Xs oscilloscope product lines introduce a novel search and analysis feature that designers can exploit to quickly identify and characterize faults and other unusual events. The WaveScan feature can locate unusual events in a single capture or scan for an event in many acquisitions over a long period of time.

Designers may select from nearly 20 search modes (such as pulse width, frequency, rise time, runt and duty cycle), apply a search condition (such as greater than, less than, in a range, outside a range, and set a value with limits) and begin scanning. In a single acquisition, WaveScan will identify the unusual event with a red box and list the associated values in a table (see the figure). From there, a user can zoom to view or apply additional analysis tools for complete debugging. Another use for WaveScan is in finding abnormalities in long waveforms that have been previously scanned.

According to the vendor, WaveScan allows for troubleshooting in ways that weren't previously possible. That's because this feature makes it possible to identify events that would not normally be selectable by an oscilloscope's hardware trigger. For example, in power-supply development, WaveScan might be used to trigger on a frequency shift. Oscilloscope users also could employ the “rarest event” search mode to identify abnormalities where the rare event is defined in terms of pulse width or rise time.

In addition to being able to search for an unusual event in a single acquisition, WaveScan can search for an event over a period of hours or days, and perform several functions once the events are found. For instance, once certain events are identified, WaveScan can take an action to stop scanning, save waveforms and continue scanning, save a screen image and continue scanning, in addition to other actions. This allows the user to accumulate a data set of unusual events and enables faster debugging.

In the WaveRunner Xi oscilloscopes, WaveScan provides additional capability. Found events can be overlaid in a “ScanOverlay” view to provide a quick and simple comparison to one another. In addition, for measurement-based scanning modes (such as a search for a frequency outside a specified range), a “ScanHistogram” can be created to show the statistical distribution of the found events. These analysis tools simplify understanding and enable faster debug.

WaveScan will be standard on all WaveSurfer Xs and WaveRunner Xi oscilloscopes including the new WaveRunner 104Xi, a four-channel 1-GHz model; the WaveRunner 204Xi, a 2-GHz model; and the WaveSurfer 104Xs, a 1-GHz scope. Sampling rates for both of the new WaveRunner models are 5 Gsamples/s on four channels, interleaved to 10 Gsamples/s. The sampling rate for WaveSurfer is 2.5 Gsamples/s on 4 channels or 5 Gsamples/s interleaved. In addition to the oscilloscope introductions, LeCroy is unveiling its ZS series of active probes, which offer 1-GHz or 1.5-GHz bandwidth, an extensive range of standard and optional probe tips and ground accessories, wide (±8-V) dynamic range, and an ability to withstand ±40-V input. For more information, see www.lecroy.com.

Acceptable Use Policy blog comments powered by Disqus