User manual

Measurements
R&S
®
RTO
147User Manual 1316.0827.02 ─ 06
3. Define the "Source" from which the reference is taken. The source can be any signal
input, math or reference waveform.
4. Select automatic "Reference level mode".
5.
Define which signal level is used as a reference. For details see "Signal level
mode" on page 154.
6. By default, the lower reference level is defined at 10% of the selected signal level,
the middle reference level at 50% and the upper reference level at 90%. Optionally,
select other "Relative levels" to be used for evaluation.
7. To determine the reference levels using average values from several histograms,
enable the "Histogram averaging" option and define an "Average Count" to define
how many histograms are averaged.
Averaging is not available if "Absolute peaks" are selected as the "Signal level
mode".
8. To define a hysteresis for the middle reference level, select the "Hysteresis" tab and
enter a percentage of the selected signal level.
A rise or fall from the middle reference value that does not exceed the hysteresis is
rejected and not considered a zero-crossing.
9. To define a tube for the high and low signal levels:
a) Select the "Tube" tab.
b) In the "Relative outer" field, define a percentage of the signal level by which the
absolute signal level may be larger than high signal level or lower than the low
signal level to be considered high or low, respectively.
c) In the "Relative inner" field, define a percentage of the signal level by which the
absolute signal level may be higher than the low signal level or lower than the
high signal level to be considered low or high, respectively.
To determine reference and signal levels manually
You can configure the reference levels manually as fixed absolute or relative values.
1. From the "Meas" menu, select "Reference Level > Levels" to open the "Measure-
ment" dialog box.
2. Select the "Levels" tab.
3. Define the "Source" from which the reference is taken. The source can be any signal
input, math or reference waveform.
4. Select manual "Reference level mode".
5. Under "Level definition", select whether you want to define the levels using absolute
or relative values.
6. Under "User level selection", select whether you want to configure the high and low
signal levels ("User signal level") or the lower, middle and upper reference levels
("User reference level").
Automatic Measurements