The Spectrum Application (RF Measurements)
R&S
®
FPL1000
367
User Manual 1178.3370.02 ─ 11
6.9.4.1
Precise Frequency (Signal Count) Marker
Access
: "Overview" > "Analysis" > "Marker Functions" > "Select Marker Function" >
"Signal Count" > "Signal Count Config"
Or
: [MKR] > "Select Marker Function" > "Signal Count" > "Signal Count Config"
The frequency count marker is not available if the tracking generator is active (see
A normal marker determines the position of the point on the trace and indicates the sig-
nal frequency at this position. The trace, however, contains only a limited number of
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 6.6.1.8, "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
FPL1000 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.
Signal counting can be performed explicitly at the current marker position ("Signal
Count" marker function), or implicitly by the R&S
FPL1000 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
"Measuring the Signal Frequency Using the
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"
Marker Usage
