Spectrum Analyzer Mode
R&S
®
Cable Rider ZPH
206
User Manual 1321.0950.02 ─ 07
You can now select a specific spectrogram frame that is in the memory of the R&S
Cable Rider ZPH.
1. Select the "Select Time Line" softkey.
The R&S Cable Rider ZPH opens an input field to define the position of the first
time-line (T1).
2. Position the time line by entering a number or moving it with the rotary knob.
Entering the value "0" sets the time line marker on the most recent frame. The
maximum value that you can enter is "1024". This is the maximum number of
frames that the R&S Cable Rider ZPH can store in its memory.
Note that not all frames are visible on the screen. If a frame is part of the history
outside the visible area, the time line is also not visible and you have to scroll
through the spectrogram to be able to see it again. See
"Scrolling through the
spectrogram"
on page 196.
The upper window displays the spectrum of the frame at the time-line position. By mov-
ing the time-line, you can thus browse through the history of spectra stored in memory.
In the marker information field, the R&S Cable Rider ZPH shows the timestamp of the
time-line.
The timestamp of the first time-line (T1) is always referred to the top-most frame (e.g. a
timestamp of 00:00:50:000 means that the data was measured 50 seconds before the
topmost frame).
1. Select the "Select Time Line" softkey again.
The R&S Cable Rider ZPH opens an input field to define the position of the second
time-line (T2).
2. Enter a number with the number keys or use the rotary knob to adjust the time line.
The R&S Cable Rider ZPH positions the second time line on the selected frame.
Again it shows the timestamp of the time line in the marker information field (ΔT
value). For the second time line (T2), the information is relative to the first one (T1).
This means that the timestamp of the second time line can be negative, if you have
set it on a frame above the first time-line.
If you scroll the time line through the frames of the spectrogram with the rotary knob,
the R&S Cable Rider ZPH shows the spectrum corresponding to the selected frame in
the upper window of the display.
Performing Spectrum Measurements
