User manual

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Signal Display
attempts to select the optimal time. If OFF is selected, the
persistence function is deactivated. Another available op-
tion is the BACKGROUND function. With this key, you can
activate or deactivate a mode which allows older signal
curves to not disappear entirely after the set persistence
time. Instead, these signals will continue to be displayed in
the background with low brightness. This display is useful
for the analysis of peak values in signals, for instance.
7.4 XY Display
The R&S®HMO3000 series features a key that allows you
to switch directly to the XY display. Two signals will be
displayed simultaneously, one in Y direction and one in X
direction. This implicates that the time base X will be repla-
ced by amplitude values of a secondsource. The resulting
signal curves for harmonic signals are known as Lissajous
guresandallowtheanalysisoffrequencyandphase
position for these two signals. In case of a nearly identical
frequencythegurewillrotate.Ifthefrequencyisexactly
identical,thegurewillstandstillandthephaseposition
can be deduced from its shape. You can activate the XY
display by pressing the XY key
19
in the VERTICAL section.
The display will divided into one large and three small dis-
play areas.
The large grid shows the XY display while the small grids
show the source for X, Y1, Y2 and Z. The small windows
feature the classical signal display as Y vs. time. The ana-
log channels can be selected as source. It is possible to
denetwosignalsasYinputanddisplayvs.xinputtoper-
form a comparison. Press the soft menu key Z SETTINGS
to determine the settings for the Z input. The function
SOURCE Z allows you to use any of the analog channels
as source for the Z input. Use the universal knob in the
CURSOR/MENU section to select the desired setting. The
Z input allows you to control the brightness of the XY sig-
nal. This can be static or dynamic, by setting an adjustable
threshold or by modulating the brightness with the ampli-
tude change of the Z input. In the MODULATION setting,
large amplitudes of the Z source will display the XY points.
Fig. 7.4: Settings in the X–Y menu
With two-channel instrument R&S®HMO3002 only basic XY
display is possible.
The transition is continuous. The setting ON|OFF displays
values below the selected threshold of the Z source and
the XY points with the lowest brightness. Values excee-
ding the threshold will be displayed with the selected
brightness. There is no transition between the two states.
You can use the universal knob or the KEYPAD button in
the CURSOR/MENU section to select the threshold.
Fig. 7.5: Settings for the Z input