3 Spectrum Analyzer Mode
3.3 Channel Power Measurement
instrument amplitude accuracy specifications only apply when Auto Sweep Time is
set to ACCuracy.
Additional amplitude errors that occur when Auto Sweep Time is set to NORMal are
usually well under 0.1dB, though this is not guaranteed. Because of the faster
sweep times and still low errors, NORMal is the preferred setting of Auto Sweep
Time. Auto Sweep Time is set to NORMal on a Preset. This means that in the Preset
state, instrument amplitude accuracy specifications do not apply.
Remote Command
[:SENSe]:CHPower:SWEep:TIME:AUTO:RULes NORMal | ACCuracy
[:SENSe]:CHPower:SWEep:TIME:AUTO:RULes?
Example
:CHP:SWE:TIME:AUTO:RUL NORM
:CHP:SWE:TIME:AUTO:RUL?
Dependencies Does not appear in Spectrum Analyzer Mode in VXT model M9421A
Preset
NORMal
State Saved Saved in instrument state
Range
NORMal|ACCuracy
Points
Sets the number of points taken per sweep, and displayed in the traces. The current
value of Points is displayed parenthetically, next to the sweep time in the lower-right
corner of the display. Using more points provides greater resolution. Using fewer
points compacts the data and decreases the time required to access a trace over the
remote interface.
Increasing the number of points does not increase the sweep time. However, it can
slightly impact the trace processing time and therefore the overall measurement
speed. Decreasing the number of points does not decrease the sweep time, but it
may speed up the measurement, depending on the other sweep settings (for
example, in FFT sweeps). Fewer points will always speed up the I/O.
Due to minimum sweep rate limitations of the hardware, the minimum sweep time
available to the user will increase above its normal value of 1 ms as the number of
sweep points increases above 15001.
Changing the number of sweep points has several effects on the instrument.Since
markers are read at the point location, the marker reading may change.The sweep
time resolution will change. Trace data for all the traces will be cleared and, if
"Sweep/Measure" on page 2037 is Cont, a new trace taken. If any trace is in average
or hold, the averaging starts over.
Due to sweep time quantization issues, the knob and up/down keys cannot be used
to adjust the number of points.
When in a split screen display each window may have its own value for points.
688 Spectrum Analyzer Mode User's &Programmer's Reference