About Trace Data

Selecting the trace data determines the following for the active trace:

The data used to create the trace.
The measurement calculation performed on the data.
The trace data that is selected affects only the active trace. Furthermore, the choices available vary with instrument configuration, such as the number of channels selected, whether demodulation is enabled, and the type of demodulation.

The easiest way to understand how Trace Data works is with a block diagram. The following block diagram shows how the VSA uses Trace Data to create Trace A:

$image\tracedata_wmf.jpg$

As seen in the block diagram, Trace Data selects the data used and the measurement calculation used to create a trace. The data can come from any of the following:

One or more input channels
A marker (OBW and ACP summary traces)
A math function
A data register
Different trace data can be selected for each trace. For instance, the spectrum of channel 1 could be displayed in trace A, the results of a math function in trace B, the time-domain waveform of channel 1 in trace C, and the contents of a data register in trace D.
Or channel 1 data could be displayed for traces A, C, and E and channel 2 data for traces B, D, and F.
Furthermore, coordinates, units, and scaling can be identical for all traces or unique to each trace.