Trace Select (Markers)

Trace Select is used to select a trace in the trace buffer for use with normal and delta markers and for use in other trace windows that contain the same trace data as the spectrogram. Trace Select can be used to select any trace in a spectrogram trace buffer.

Trace Select is available only when the active trace is a spectrogram display and the measurement is paused. When the measurement is running, the current trace is always the most recent trace (the bottom trace in a spectrogram display).

When Trace Select is selected, the Trace: box in the Markers > Spectrogram tab indicates which trace is selected. For example, when the Trace: box shows a value of 544 Scan, the marker is currently on the 544th trace in the spectrogram buffer.

Spectrograms use a horizontal line to indicate the selected trace (and a vertical line to show the current marker position on the trace).

To select a trace, type a value in the Trace: box. Either select a trace by scan number or by time relative to when the measurement was started.

If a scan is specified, the value typed in the Trace: box is limited to the number of traces specified by Buffer Depth. For example, if Buffer Depth is set to 1000, valid values for Trace: are from 1 to 1000 scans. The spectrogram may show more traces than are in the buffer but markers can only be applied to traces included in the buffer.

Automatic Updating of Other Traces

Another feature of Trace Select is that selects the trace to show in all other visible trace windows that contain the same trace data as the spectrogram display.

The easiest way to understand this feature is to try it. Display two trace windows (Window > Trace Layout > Stack 2) and select the same trace data for both trace windows (for example, Spectrum). Enable spectrogram for one of the trace windows (set Trace > Spectrogram / 3D Map > 3D Map to Spectrogram). Play the measurement to fill the spectrogram display and then pause the measurement. Select the Trace Select check box, click in the Trace box, and use the up and down arrow keys to change the trace number. Watch Trace B update while scrolling through traces in the Trace A spectrogram.

Click and drag the spectrogram horizontal marker line to select traces.