Customizing Oscilloscope Measurements

Gating

Use gating options to limit the source of oscilloscope measurements displayed in the measurement table.

• Screen—Displays only the data visible in the large panel's Time domain graph.
• Record—Displays the data in the full record.

Reference Levels

Customize the oscilloscope measurements displayed on the measurement table by adjusting the reference levels and the High-Low method from the Settings tab of the Measurements window.

High, Mid, and Low Reference Levels

Reference levels are range values that divide a waveform into high, middle, and low sections by intersecting the waveform at specified amplitude. Use reference levels to ascertain rise and fall times, calculate waveform cycles, and customize some oscilloscope measurement types. In InstrumentStudio, set reference levels by either absolute voltage levels or the percentage of the waveform to acquire. The following oscilloscope measurement types are calculated using reference levels:

Reference Level Unit

Use the reference level Unit settings to specify whether reference levels should be interpreted as percentages of the waveform or as absolute levels.

• Percentage—Interprets the reference levels as a percentage using the selected High-Low method.
• Volts—Interprets the reference levels as absolute levels, in units of volts.

High-Low Method

If you set the reference level Unit setting to Percentage, configure how the state levels are computed by selecting the High-Low method:

• Auto-select—Determines whether the histogram bins that correspond to the high and low state levels each have over 5% of the total hits. If so, the device returns those results. If not, the device uses the Peak High-Low method. The Auto-select High-Low method provides an answer for either a square wave (by ignoring the overshoot and undershoot) or a triangle wave (where the Histogram High-Low method fails).
• Histogram—Computes state levels using the histogram bins with the maximum number of hits in the upper and lower regions of the waveform. The upper and lower regions of the waveform include the upper and lower 40% of the peak-to-peak range of the waveform.
• Peak—Searches the waveform for its maximum and minimum levels.