1003
Marker
Query Count Value
Queries the frequency count. The query returns the absolute count unless the specified marker is in Delta
mode, then it returns the relative count. If the marker is off, or the marker is on but the counter is off, the
test set will return "not a number" to a SCPI count query. A marker with no stored count, or a non-Fixed
marker on a stored trace, will also return not a number to a SCPI count query. Note this result may
simply mean that the first sweep after the counter turned on has not yet completed.
Understanding the Marker Counter
See “Counting Off-screen Markers” on page 1004.
See “Delta Marker” on page 1004.
See “Fixed Markers” on page 1004.
See “More Information on "Counter"” on page 1004.
Using the internal counter we can count the frequency of a marker, but we cannot count while we are
actually sweeping. So, once we are done with a sweep, we move to the selected marker frequency and
count that frequency. Then, if the marker is a Delta marker, the count is also taken for its reference
marker. The count is actually performed by moving the LO to the frequency (or frequencies in the case
of a delta marker) we wish to count. The count is executed on a marker by marker basis and no further
count is taken until after the next sweep (even if the marker moves before another sweep has completed).
The Marker Count is taken by tuning the test set to the frequency of the marker and counting the IF, with
the test set not sweeping. The count is adjusted for display by adding or subtracting it (as appropriate)
from the LO frequency, so that you see a count that represents the signal frequency. This is true even if
External Mixing is on. Since all this happens between sweeps, you never see the test set retuning to do
the counts.
If you wish to see the entered frequency of a counted marker it will appear in the active function area
when that marker is selected (for Fixed markers, you have to press the Marker, Fixed key to select Fixed
Couplings If the selected marker is Off when the counter is turned on, the selected marker
is set to Normal and placed at center of screen on the trace determined by the
Marker Trace rules.
If a marker which is OFF is selected while the counter is on, the counter
remains on, but since the marker is off, the count is undefined. In this case, the
test set returns "not a number" to a SCPI count query.
The counter is turned OFF when the selected marker is turned OFF.
Preset OFF
State Saved The state of the counter (on/off) is saved in instrument state. In the case of
Fixed markers, the count stored in the marker is saved in instrument state.
Initial S/W Revision Prior to A.02.00
Remote Command: :CALCulate:MARKer[1]|2|3|4|5|6|7|8|9|10|11|12:FCOunt:X?
Notes: This query does NOT cause the specified marker to become selected.
Initial S/W Revision: Prior to A.02.00