MDO3000 Programmer Manual.pdf - 第613页

Commands Listed in Alphabetical Order RF:SPECTRogr am (No Query Form) Clears the spectrogram. Conditions A vailable for MDO4000/B/C a nd MDO3000 series models only . Group RF Syntax RF:SPECTRogra m {CLEAR} Arguments CLEA…

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Commands Listed in Alphabetical Order
Group
RF
Syntax
RF:SPAN <NR3>
RF:SPAN?
Related Commands
RF:FREQuency, RF:STARt, RF:STOP
Arguments
<NR3> is a floating point number.
Examples
RF:SPAN 2E9 sets the span to 2 GHz.
RF:SPAN? might return 10.0000E+6, indicating the span is 10MHz.
RF:SPANRbwratio
This command specifies the ratio of the span to the resolution bandwidth (RBW)
that will be used when the RBW Mode is set to AUTO. (In order to set the RBW
Mode to AUTO, use the command RF:RBW:MODe.)
The span is the width of the frequency domain trace in Hz, which is equal to the
stop frequency minus the start frequency. The RBW is the width of the narrowest
measurable band of frequencies in a frequency domain trace. The default RBW
ratio is a factor of 1000.
Conditions
MDO3000, MDO4000/B, or MDO4000C models with option SA3 or SA6 only.
Group
RF
Syntax
RF:SPANRbwratio <NR3>
RF
:SPANRbwratio?
Arguments
<NR3> is a floating point number.
Examples
RF:SPANRbwratio 1000 would force the scope to adjust the RBW to one
one-thousandth of the span.
RF:SPANRbwratio? might return 1.0000E+3, which means the RBW has been
set to one one-thousandth of the span.
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Commands Listed in Alphabetical Order
RF:SPECTRogr
am (No Query Form)
Clears the spectrogram.
Conditions
Available for MDO4000/B/C and MDO3000 series models only.
Group
RF
Syntax
RF:SPECTRogram {CLEAR}
Arguments
CLEAR clears the spectrogram.
Examples
RF:SPECTR CLEAR clears the spectrogram.
RF:SPECTRogram:NUMSLICEs? (Query Only)
This query returns the number of spectrogram slices that are currently being
rendered. A spectrogram slice is a section of the spectrogram representing one
interval, or slice, of time in the spectrogram record.
Conditions
MDO3000, MDO4000/B, or MDO4000C models with option SA3 or SA6 only.
Group
RF
Syntax
RF:SPECTRogram:NUMSLICEs?
Related Commands
RF:SPECTRogram:STATE,RF:SPECTRogram:NUMSLICEs?,
Examples
RF:SPECTRogram:NUMSLICEs? might return 85, indicating that the spectrogram
is made up of 85 individual time slices.
RF:SPECTRogram:SLICESELect
This command specifies the spectrogram slice number that is to be displayed.
The slice can only be selected or changed when acquisitions have been stopped.
As soon as acquisitions start again, the slice number is reset to 0 (the latest slice).
Attempts to select a slice number outside of range, or when acquisitions are
MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual 2-583
Commands Listed in Alphabetical Order
running, are ig
nored. The query form returns the currently selected spectrogram
slice.
To use this com
mand, first turn on the spectrogram (RF:SPECTRogram:STATE).
Then query the number of slices (RF:SPECTRogram:NUMSLICEs?). Stop the
acquisition when you’ve reached the number of desired slices. Then select the
slice to display (RF:SPECTRogram:SLICESELect).
Each slice of the spectrogram corresponds to a single RF acquisition. The FFT
samples the entire spectrum for the incoming signal (at the rate with which new
spectrums are acquired). The newest spectrum is on the bottom edge of the
spectrogram, and the oldest is on the top edge. When the oscilloscope is stopped,
you can sc
roll “back in time” through the spectrogram using the spectrum slice
control. When you select a spectrogram slice, it is displayed in the bottom
window as the RF Normal trace.
NOTE. When acquisitions are stopped and the spectrogram is displayed, the
spectrogram slice trace is displayed as the RF Normal frequency domain trace.
Condi
tions
MDO3000, MDO4000/B, or MDO4000C models with option SA3 or SA6 only.
Group
RF
Syntax
RF:SPECTRogram:SLICESELect <NR1>
RF:SPECTRogram:SLICESELect?
Related Commands
RF:SPECTRogram:STATE, RF:SPECTRogram:NUMSLICEs?,
Arguments
<NR1> is an integer that specifies the spectrogram slice number that is to be
displayed.
For the MDO4000/B/C models, allowable slice numbers range from 0 to –327 in
full-screen mode, and 0 to –147 in split-screen mode. For MDO300
0models,
there is no split-screen mode – the slice numbers always range from 0 to –197.
(The range is negative because the numbering starts with the latest slice (0) and
proceeds backwards in time.)
Examples
RF:SPECTRogram:SLICESELect –5 would select the slice that is five
acquisitions before the most recent one.
RF:SPECTRogram:SLICESELect? might return 0, indicating that the latest
spectrogram slice is being displayed.
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