How to Use Measurement Statistics to Set Up Triggers

Figure 1.  Histogram of the different pulse widths occurring
in a pulse-width modulated rectangular pulse train.

Triggering is an essential element in all modern digital oscilloscopes.  The trigger synchronizes the oscilloscope’s data acquisition with a user-specified event on the signal, be that an edge, threshold crossing or a specific signal characteristic. Teledyne LeCroy Smart Triggers can trigger oscilloscope acquisitions based on properties such as a period, width, low signal amplitude, slew rate or signal loss. These trigger types are ideal for capturing transient events like glitches, but they require knowing at least a range of possible values for the trigger to detect.

Intermittent transient events and glitches are among the most frustrating problems to detect and solve. This is especially true if you have no idea about the nature of the transient. However, you can use the oscilloscope’s measurement tools to help locate these bothersome transients, then use that information to set up your trigger to capture them when they occur. Here’s how.

How to "Layer" Measurement Tools

Figure 1: Multi-grid display "layers" multiple
measurement tools to find hidden glitch.

Teledyne LeCroy oscilloscopes have four, distinct sets of measurement tools, including measurement graticules, cursors, parameters and graphs. These tools developed historically and are designed to be “layered” on multi-grid MAUI® oscilloscopes so that each addition brings a new level of understanding and insight. Even on oscilloscopes that do not have multi-grid displays, as shown here, several measurement tools can be applied at once for added insight. Read on to see how, properly combined, they can help you find waveform anomalies and assess their frequency of occurrence in a few, simple steps.

Getting The Most Out Of Your Oscilloscope: Cursors and Parameters

Figure 1: Cursors (top) and parameter
measurements (bottom) are both
powerful tools in their own right

Oscilloscopes give us a wealth of tools with which to view, measure, and analyze the performance of a circuit. Broadly speaking, two classes of such tools are cursors and parameter measurements. Taken on their own, both classes afford the user a great deal of capability. Put them together, though, and you can really start to gain deep insights into what's going on with a waveform.

The Periodic Table of Oscilloscope Tools: Measure

Figure 1: Measure
tools are at the heart
of an oscilloscope's
utility

An oscilloscope is only as good as the tools it provides to users for acquiring, viewing, measuring, analyzing, and documenting waveforms. We present an overview of our deep collection of oscilloscope tools in our Periodic Table of Oscilloscope Tools, and in prior Test Happens posts, we've surveyed the Capture and View categories. Today we'll break down the Measure section of the Table.