R&S FSMR, Operating Manual, Page: 240 / 955

Traces - Analyzer R&S FSMR
1166.3363.12 4.11-2 E-2
completely new or based on the previous results.
Traces can be displayed, blanked and copied. Traces can also be corrected with the aid of
mathematical functions.
The measurement detector for the individual display modes can be selected directly by the user or set
automatically by R&S FSMR.
The default setting is trace 1 in the overwrite mode (
CLEAR / WRITE) , the other traces 2 and 3 are
switched off ( BLANK ).
The CLEAR/WRITE, MAX HOLD, MIN HOLD, AVERAGE, VIEW and BLANK softkeys are mutually
exclusive selection keys.
SELECT
TRACE
The SELECT TRACE softkey activates the entry for the active trace (1, 2, 3).
IEC/IEEE-bus command -- (selected via numeric suffix of
:TRACe
)
CLEAR/
WRITE The CLEAR/WRITE softkey activates the overwrite mode for the collected
measured values, ie the trace is overwritten by each sweep.
In the
CLEAR/WRITE display mode all the available detectors can be selected. In
the default mode the autopeak detector (setting AUTO ) is selected.
Each time the CLEAR/WRITE softkey is actuated, R&S FSMR clears the
selected trace memory and starts the measurement anew.
IEC/IEEE-bus command
DISP:WIND:TRAC:MODE WRIT
MAX HOLD
The MAX HOLD softkey activates the max peak detector.
R&S FSMR saves the sweep result in the trace memory only if the new value
is greater than the previous one.
The detector is automatically set to
MAX PEAK . The maximum value of a
signal can thus be determined over several sweeps.
This is especially useful with modulated or impulsive signals. The signal
spectrum is filled up upon each sweep until all signal components are
detected in a kind of envelope.
Pressing the
MAX HOLD softkey again clears the trace memory and restarts
the max hold mode.
IEC/IEEE-bus command
DISP:WIND:TRAC:MODE MAXH
AVERAGE
The AVERAGE softkey activates the trace averaging function. The average is
formed over several sweeps. Averaging can be performed with any of the
detectors available. If the detector is automatically selected by R&S FSMR,
the sample detector is used.
Depending on the setting of AVG MODE LOG / LIN, the logarithmic level
values or the measured power/voltage values are averaged.
Averaging is restarted every time the
AVERAGE softkey is pressed. The
trace memory is always cleared.
IEC/IEEE-bus command
DISP:WIND:TRAC:MODE AVER
Description of averaging
Averaging is carried out over the pixels derived from the measurement samples. Several measured
values may be combined in a pixel. This means that with linear level display the average is formed over
linear amplitude values and with logarithmic level display over levels. For this reason the trace must be
measured again when changing between
LIN and LOG display mode. The settings CONT/SINGLE
SWEEP and running averaging apply to the average display analogously.
There are two methods for calculating the average. For a sweep count = 0 , a running average is
calculated according to the following formula:
TRACE
9 * TRACE meas. value
10
=
+
Due to the weighting between the new measured value and the trace average, past values have
practically no influence on the displayed trace after about ten sweeps. With this setting, signal noise is