HP 54710A User's Reference Manual page 111

Define Measure Menu
The define measure menu sets the measurement points (thresholds)
where the automatic measurements are made. The menu influences
the measurement algorithm by allowing you to use the standard IEEE
measurement points, or by allowing you to customize the
measurements with the user defined selections.
Figure 7-1 is a waveform drawing that shows some of the standard
measurement thresholds.
See Also Chapter 13, Measurements, for details about the algorithms used to calculate
the thresholds for the automatic measurement feature.
Figure 7-1
Standard measurement thresholds
7–2