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Signal Display
7 .3 Signal Intensity Display and Persistence
Function
The default setting (indicated as active when the INTENS/
PERSIST
7
key is illuminated in white) allows you to use
the universal knob to change the intensity of the signal
display to anywhere from 0% to 100%. Persistence mode
allows the display of varying signals by enabling the inst-
rument to write several signals on the display simultane-
ously. It is also possible to induce accelerated aging of
signals with an adjustable persistence from 50ms to infi
-
nite. Signals occurring less frequently will be displayed in
darker color and signals occurring more frequently will be
displayed in lighter color. Press the INTENS/PERSIST key in
the soft menu to select this mode.
The soft menu items TRACE, GRID and BACKLIGHT allow
you to use the universal knob in the CURSOR/MENU sec-
tion to adjust the
grid intensity and the backlighting. The
soft menu SETTINGS allows you to select the persistence
settings for the signals on the screen. The persistence
function ensures that signals will not be replaced when
the screen is updated. Instead, the signals will pause for a
specific amount of time and then slowly begin to fade. This
type of display is very similar to that of an analog oscillo-
scope. There are three possible settings for the duration of
the persistence: OFF, AUTOMATIC and MANUAL.
The option MANUAL allows you to set a duration of 50ms
to infinite by using the universal knob or the KEYPAD
key. If a finite duration was selected, new signals will be
written on top of one another within this timeframe where
the most recent captures will be displayed more brightly
than older signals. For instance, if 300 ms is selected, the
display for the signal curves will become darker in 50ms
intervals and will be erased after 300 ms. The AUTOMATIC
setting allows you to select the automatic configuration of
the persistence. If this setting is activated, the instrument
attempts to select the optimal time. If OFF is selected, the
persistence function is deactivated.
Another available option is the BACKGROUND function.
With this key, you can activate or deactivate a mode which
allows older signal curves to not disappear entirely after
Fig. 7.2: Persistence function
the set persistence time. Instead, these signals will con-
tinue to be displayed in the background with low bright-
ness. This display is useful for the analysis of peak values
in signals, for instance.
7 .4 XY display
The R&S®HMO1002 resp. R&S®HMO1202 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 replaced by amplitude values of a
secondsource. The resulting signal curves for harmonic si-
gnals are known as
Lissajous figures and allow the analysis
of frequency and phase position for these two signals. In
case of a nearly identical frequency the figure will rotate. If
the frequency is exactly identical, the figure will stand still
and the phase position can be deduced from its shape.
You can activate the XY display by pressing the UTIL key
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in the VERTICAL section. The display will divided into
one large and three small display areas. The large grid
shows the XY display while the small grids show the
source for X and Y. The small windows feature the classi-
cal signal display as Y vs. time. The analog channels can
be selected as source.