Cursor Delta Readouts

Macros: CursMode=Delta, DeltX, DeltY

To the right of the solid and dotted readouts are the Delta/Sigma readouts. The default mode is Delta, indicated by the triangle symbol on the small button at the left end of the Y value. In this mode, the readouts show the difference between the dotted and solid cursors; the Delta values are always computed as Dotted minus Solid.

You can use Delta X to easily measure the time between certain features of a waveform, or, by setting solid and dotted cursor to read different channels, the time between features on different channels. If one channel is a stimulus and the other is a response, you can measure response latency. (You can also measure latency using the response channel alone, if the Trigger is set to start the display from the stimulus channel.)

Likewise, Delta Y (below Delta X) can be used to show the difference between peak heights, or peak-to-dip height, or peak-to-baseline height, for features on the same or different channels.

In Spectrum mode, the Delta readouts allow easy measurement of frequency and amplitude differences. The Peak, Track, and Ratio buttons at the bottom of the Spectrum dialog can enhance this further: If a cursor is over a peak, the Peak option will interpolate from the adjacent spectral lines to give greatly improved precision. The Track option causes the solid cursor to automatically track the highest peak in the spectrum. The Ratio option shows the ratio of the cursor frequencies in the Delta X display, which is useful for harmonic measurements.

Macro Notes:

CursMode=Delta or CursMode=0 sets the Delta cursor readout mode, while CursMode=Sigma or CursMode=1 sets Sigma mode. CursMode=x toggles between them.

DeltX and DeltY are internal read-only variables that hold the current Delta X and Y values, respectively, in the same units that are shown on-screen. Note that if Sigma mode is active, DeltY actually returns the Sigma value.

See also Cursors and Readouts, Cursor Sigma Readouts