The Spectrum Application (RF Measurements)
R&S
®
FPL1000
401
User Manual 1178.3370.02 ─ 09
Table 7-27: Correlation between number of sweep points and number of frames stored in the history
buffer
Sweep Points
Max. History Depth
≤
1250
20000
2001
12488
4001
6247
8.001
3124
16.001
1562
32.001
781
The scaling of the time axis (y-axis) is not configurable. However, you can enlarge the
spectrogram display by maximizing the window using the "Split/Maximize" key.
Frame analysis - Frame count vs. sweep count
As described for standard spectrum sweeps, the sweep count defines how many
sweeps are analyzed to create a single trace. Thus, for a trace in "Average" mode, for
example, a sweep count of 10 means that 10 sweeps are averaged to create a single
trace, or frame.
The frame count, on the other hand, determines how many frames are plotted during a
single sweep measurement (as opposed to a continuous sweep). For a frame count of
2, for example, 2 frames will be plotted during each single sweep. For continuous
sweep mode, the frame count is irrelevant; one frame is plotted per sweep until the
measurement is stopped.
If you combine the two settings, 20 sweeps will be performed for each single sweep
measurement. The first 10 will be averaged to create the first frame, the next 10 will be
averaged to create the second frame.
As you can see, increasing the sweep count increases the accuracy of the individual
traces, while increasing the frame count increases the number of traces in the diagram.
Especially for "Average" or "Min Hold" and "Max Hold" trace modes, the number of
sweeps that are analyzed to create a single trace has an effect on the accuracy of the
results. Thus, you can also define whether the results from frames in previous traces
are considered in the analysis for each new trace ("Continue Frame").
Tracking absolute time - timestamps
Alternatively to the frame count, the absolute time (that is: a
timestamp
) at which a
frame was captured can be displayed. While the measurement is running, the time-
stamp shows the system time. In single sweep mode or if the sweep is stopped, the
timestamp shows the time and date at the end of the sweep.Thus, the individual
frames can be identified by their timestamp or their frame count.
Trace Configuration
