Common analysis and display functions
R&S
®
FSVA3000/ R&S
®
FSV3000
534
User Manual 1178.8520.02 ─ 08
points. Depending on the selected span, each trace point can contain many measure-
ment values. Thus, the frequency resolution of each trace point is limited.
(See also
Chapter 6.5.1.8, "How much data is measured: sweep points and sweep
Frequency resolution is further restricted by the RBW and sweep time settings.
To determine the frequency of a signal point accurately without changing the sweep
settings, the R&S
FSV/A is equipped with a signal counter. The signal counter sets the
RF to the current marker position, then counts the zero crossings of the IF (thus the
term signal
counter
) and derives the precise frequency value.
To determine the frequency accurately using the signal counter function, the marker
must be sufficiently close to the actual signal (for a 3-dB Gauss filter, the delta must be
less than 2*RBW). Usually, the marker peak function detects a trace point that is close
enough. However, for a large span or a small number of sweep points, the result can
be inaccurate.
Signal counting can be performed explicitly at the current marker position ("Signal
Count" marker function), or implicitly by the R&S
FSV/A for certain functions.
Signal counting is only possible while the instrument is not sweeping. Thus, to perform
a signal count for a marker, the sweep is stopped at the marker position. The fre-
quency is determined with the desired resolution and then the sweep is allowed to con-
tinue.
A measurement example is described in
Chapter 5.2.3.2, "Measuring the signal fre-
quency using the signal counter"
Signal counters are not available for measurements on I/Q-based data.
Remote commands:
"Example: performing a highly accurate frequency measurement using the signal count
marker"
CALCulate<n>:MARKer<m>:COUNt:RESolution
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Marker usage
