3 Spectrum Analyzer Mode
3.2 Swept SA Measurement
Return the counted frequency:
:CALC:MARK2:FCO:X?
Notes Fixed markers are not counted, but a Fixed marker will have a count stored in it if it is selected or is
the reference marker for the selected marker. The count already in the marker is stored when the
marker becomes fixed and if there is none or the marker moves (for example, Peak Search) it is
counted and stored after the next sweep
If a Fixed marker has a count stored in it, that count is displayed when the marker is selected, and
used as the reference count when that marker is a reference marker
If a Fixed marker has a count stored in it, that count is deleted if the Marker X is adjusted
If a Fixed marker has a count stored in it, and a search function is performed using the Fixed marker
while the counter is on, the count stored in the marker is updated
If a Fixed marker has a count stored in it, and is a reference marker, and the reference is moved to a
valid trace point by re-zeroing the delta (by pressing Delta again or sending the DELTa command)
while the counter is on, the count stored in the marker is updated
This command causes the specified marker to become selected
Dependencies Unavailable (grayed-out and OFF) if the Gate function is on
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 that 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 instrument 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
Annotation The absolute count is displayed for Normal markers. The difference between the count and the
reference marker’s count is displayed for Delta markers. A Fixed marker with no saved count, or a
non-Fixed marker on a trace which is not updating, will show three dashes in the count block (---),
and return not a number to a SCPI count query. This is true when the marker is selected or when it is a
reference marker, and its Delta marker is selected
Note that when the count is undefined, the Count value (result) itself will display as “---“ but any text
before or after the value is retained. Hence, an undefined count for Marker 1 (for example) would
display as “Cnt1 --- Hz” as long as the value is undefined
The format of the frequency counter display is:
Cnt<n> <value> where n is the marker number, for example
Cnt1 25 386 243 226.493 Hz
If the marker is a delta marker then a leading delta symbol appears, as:
ΔCnt1 –25 386 243 226.493 Hz
The resolution of the frequency counter display is set by the following equation:
LSDDisplayed = 10 ^ (floor (–4.7 - log (Gate_Time))
with the further restriction that the displayed resolution must always fall in the 1 Hz to .001 Hz range.
Thus, for 2 ms (log 2 ms = –2.69897) and longer gate times, the counter resolution is 0.001 Hz
376 Spectrum Analyzer Mode User's &Programmer's Reference
To Next Page
Loading...
Need help?
General
