User manual

33
Measurements
To move cursors, press the universal knob in the CURSOR/
MENU section and position the cursor by turning the univer-
sal knob. The measurement types have the following func-
tions. The measurement results are displayed at the bottom
of the screen. If “n/a” is displayed, the measurement is not
applicable to the signal. For instance, this may be the case
for a voltage measurement on a POD because only logic sta-
tes without voltage reference are displayed here. If “?” is dis-
played, the display does not show a complete measurement
result. For instance, the period to be measured may not
displaycompletelyandcanconsequentlynotbeidentied.
If the function AUTOM. SOURCE is activated (ON), the cur-
rently targeted channel will be used as source for the mea-
surement automatically. If the setting is deactivated (OFF),
the channel set under SOURCE will be applied even if it is
not targeted. Pressing the soft menu key SET TO TRACE
places the selected cursors in their optimal position on the
signal curve. This allows very fast and typically optimal au-
tomatic positioning of the cursors. For the most part, only
netuningisrequiredatthispointandthetediousmajor
adjustments to the cursors will no longer be necessary.
In case the automated function SET TO TRACE does not
provide the anticipated results due to complex signals, you
can press the key SET TO TRACE to position the cursors
inapredenedstartingposition.Thisallowsyoutoreturn
distant cursors to the screen. The soft menu key GLUE TO
TRACE allows cursors to stay on the selected data point
without changing the position in the measurement signal
evenifthescalingismodied(cursorswillbe„glued“to
the signal). This function can be activated or deactivated.
If this mode is deactivated, the cursor stays in position
on the screen if scaling occurs. With GLUE TO TRACE
deactivated, the measured value changes while it remains
unmodiedwhenthemodeisactivated.
The cursors will be deactivated by pressing the CURSOR
MEASURE key. The cursor menu will be closed.
8.2 Automatic Measurements
The R&S®HMO3000 series features cursor measurements
and also various automatic measurements. These may be
activated by pressing the key AUTO MEASURE
11
in the
section ANALYZE. This menu allows you to select up to six
automatic measurement functions by using the soft menu
key MEAS. PLACE and the universal knob in the CURSOR/
MENU section. Following automatic measurement types
can be selected:
MEAN VALUE: This mode measures the mean
value of the signal amplitude (Mean). If the sig-
nalisperiodic,therstperiod on the left of the
screen will be used for the measurement. The measure-
ment will only be applied to the selected channel.
RMS VALUE:Thismodeidentiestheeffec-
tive value from the displayed view of the signal.
Ifthesignalisperiodic,therstperiod on the
left of the screen will be used for the measurement. The
effective value is not applied to a sine signal will be calcu-
lated directly (so-called TrueRMS). The measurement will
only be applied to the selected channel.
PEAK-PEAK: This mode measures the diffe-
rence in voltage between the maximum and
the minimum peak value of the signal within
the displayed view (V
pp
).
PEAK + : This mode measures the maximum
voltage value in the displayed view of the
screen. The measurement will only be applied
to the selected channel (V
p+
).
PEAK – : This mode measures the minimum
voltage value in the displayed view of the
screen. The measurement will only be applied
to the selected channel (V
p-
).
FREQUENCY:Thismodeidentiesthefre-
quency of the signal from the reci-procal value
oftherstsignalperiod T (f). The measurement
will only be applied to the selected channel.
PERIOD: This mode measures the duration of
the signal period T. The periodidentiesthe
duration between two equal values of one peri-
odically repeated signal.
AMPLITUDE: This mode measures the am-
plitude of a square wave signal (VAmp). This
mode calculates the difference in voltage bet-
ween the upper and the lower level (V
base
and V
top
). The
measurement will only be applied to the selected channel
and requires a minimum of one complete period of a trig-
gered signal.
TOP LEVEL: This mode measures the mean
voltage level of an upper square wave (V
Top
).
This mode calculates the mean value of the
slope (without overshoot). The measurement will only be
applied to the selected channel and requires a minimum of
one complete period of a triggered signal.
BASE LEVEL: This mode measures the mean
voltage level of the lower square wave (V
Base
).
This mode calculates the mean value of the
slope (without overshoot). The measurement will only be
applied to the selected channel and requires a minimum of
one complete period of a triggered signal.
PULSE WIDTH +: This mode measures the
width of the positive pulse. A positive pulse
consists of a rising slope followed by a falling
slope.Thismeasurementtypeidentiesthetwoslopes
and calculates the pulse width from their time difference.
The measurement will only be applied to the selected
channel and requires a minimum of one completely dis-
played period of a triggered signal.