# Delta Time

Δ Time (Delta Time) measures the edge-to-edge time differences on a single waveform or between two separate waveforms. This measurement may be compatible with PAM signals, depending on the PAM waveform.

Measurement Message Resolution
Results Message | Do this …
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Edge? | Increase the time scale to display more waveform edges.

You can define the edge number, direction, and threshold used for the measurement as well as the waveform source for each edge. The measurement can also be restricted to a region. An annotation label is placed at the time of the first edge source (start) and at the time of the second edge source (stop).

PAM Compatibility. Because this measurement is based on waveform top and base levels and the passing of the waveform's edge through lower, middle, and upper thresholds, the measurement is not designed for PAM signals. However, the measurement may be able to be made on PAM signals if the waveform top and base definitions are manually set. This can be attempted using the Thresholds tab of the Configure Measurements dialog box. The measurement must be made using the same top and base.

This measurement may be compatible with PAM signals, depending on the PAM waveform.

Perform Δ time on single-valued waveforms only.

The instrument counts the waveform edges from the left edge of the display graticule, instead of at the reference point.

Specify the edge parameters in the Delta Time Definition tabbed page of the Configure Measurements dialog box. Define the threshold levels in the Thresholds tabbed page of the Configure Measurements dialog box. The edges you specify must appear on the display graticule.

You must have more than one source available on in order to select the edge of a second waveform as a source for the measurement.

The measurement can be performed on any waveform that is displayed in one of a Waveform content windows.

## Configurable Measurement Parameters

This measurement is affected by the following settings (choose Measure > Thresholds...):

- Thresholds tab

## To measure

1. Click the button.
2. Select the measurement source (channel, waveform memory, or function), edge directions, and thresholds.

3. Select the Region in which to make the measurement:

   - Displayed Waveform — is what you see in the waveform window (which can be a zoomed-in view of the complete waveform).
   - Entire Waveform — specifies the complete waveform.
   - Region N — If regions are enabled for the selected signal, you can select one of those regions.

   If you want to make a two-source measurement (like Δt, Phase, or Crossing) within a region, global regions (which are defined for all signal sources) are required.

## SCPI Command

`:MEASure:HORizontal:DTIMe`