34
Subject to change without notice
M e a s u r e m e n t s
on the signal curve. This allows very fast and typically optimal
automatic positioning of the cursors. For the most part, only
fine tuning is required at this point and the tedious major adjust-
ments to the cursors will no longer be necessary. As previously
described, the cursors can also be selected by pressing the
universal knob and may be positioned by turning the universal
knob. 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
predefined 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 modified (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
unmodified when the mode is activated.
Pushing again the button CURSOR MEASURE switch off al
cursors.
8.2 Auto measurements
The HMO series features cursor measurements and also
various automatic measurements. These may be activated by
pressing the key AUTO MEASURE
11
in the section ANALYzE
of the control panel.
Fig. 8.2: Menu for the automatic measurements settings
This menu allows you to select up to six automatic measurement
functions by using the soft menu key MEAS. PLACE and the
universal knob. A maximum of two measurements are possible
simultaneously. These may originate from two different sources.
The measurement source (soft menu SOURCE) is indicated by
the font color of the respective result. The results are displayed
at the bottom of the screen. If “n/a” is displayed, the measure-
ment is not applicable to the signal. For instance, this may be
the case for a voltage measurement on a POD because only
logic states without voltage reference are displayed here. If “?”
is displayed, 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 identified.
The list of available sources only includes displayed
channels (possible sources are analog, digital and
mathematical channels).
The following kinds of measurement are available:
MEAN:
This mode measures the mean value of the signal amplitude.
If the signal is periodic, the first
period on the left of the screen
will be used for the measurement. The measurement will only
be applied to the selected channel.
RMS:
This mode identifies the effective value from the displayed view
of the signal. If the signal is periodic, the first
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 calculated directly
(so-called TrueRMS). The measurement will only be applied to
the selected channel.
PEAK–TO–PEAK:
This mode measures the difference in voltage between the
maximum and the minimum peak value of the signal within
the displayed view.
PEAK + :
This mode measures the maximum voltage value in the dis
-
played view of the screen. The measurement will only be applied
to the selected channel.
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.
FREQUENCY:
This mode identifies the frequency of the signal from the reci-
procal value of the first signal
period T. The measurement will
only be applied to the selected channel.
PERIOD:
This mode measures the duration of the signal period T. The
period identifies the duration between two equal values of one
periodically repeated signal.
AMPLITUDE:
This mode measures the amplitude of a square wave signal. This
mode calculates the difference in voltage between 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 triggered signal.
UPPER LEVEL:
This mode measures the mean voltage level of an upper square
wave. This mode calculates the mean value of the slope (with
-
out overshoot). The measurement will only be applied to the
selected channel and requires a minimum of one complete
period of a triggered signal.
LOWER LEVEL:
This mode measures the mean voltage level of the lower square
wave. This mode calculates the mean value of the slope (with
-
out 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 identifies 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 displayed period of a triggered signal.
