Rohde & Schwarz FPC Series, User Manual

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The Spectrum Application
R&S
®
FPC
85 User Manual 1178.4130.02 ─ 07
move down one position, so that the present frame is always on top of the diagram.
Therefore, the sequence of frames is chronological.
Selecting the spectrogram result display
1. Press the "Meas" key to open the measurement menu.
2. Select the "Measurement Mode" menu item to open the measurement mode menu.
3. Select the "Spectrogram" menu item.
The R&S FPC starts the recording of the spectrogram.
By default, the spectrogram result display is made up out of two windows. The upper
window shows the
measured spectrum as a line trace. The lower window shows the
measurement results in a spectrogram. The amount of information in the spectrogram
is restricted by the internal memory of the R&S
FPC. The R&S FPC can store up to
1024 frames (= line traces). When the measurement runs longer, the oldest frames are
deleted. As the height of the display is smaller than 1024 pixels, some of the data
becomes invisible after a time (but remains in the memory).
● Spectrogram Recording .......................................................................................... 85
● Color Definition ........................................................................................................87
● Spectrogram Playback ............................................................................................90
14.2.7.1 Spectrogram Recording
When you are in continuous sweep mode, the R&S FPC starts to record spectrogram
data when you enter the spectrogram mode. You can see that the spectrogram result
display fills up, as each sweep adds an additional line to the spectrogram.
When you are in single sweep mode, the R&S FPC does not add a line to the spectro-
gram until you initiate the next single sweep.
Controlling the spectrogram update
In continuous sweep mode, you can interrupt the spectrogram recording.
1. Press the "Meas" key to open the measurement menu.
2. Select the "Hold" menu item.
The spectrogram recording stops. No more new lines are added to the spectro-
gram.
The measurement itself, however, does not stop. The line trace in the spectrum
display is still updated continuously. If you want to stop the measurement com-
pletely, you have to stop it by selecting
single sweep mode . In that case, the
R&S FPC finishes the current sweep and stops the measurement. It keeps the
spectrogram data that has already been recorded.
3. Select the "Hold" menu item again.
The R&S FPC resumes updating the spectrogram.
Measurements and Result Displays