MDO3000 Programmer Manual.pdf - 第87页
Command Groups T able 2-37: RF Commands (cont.) Item Description RF:SPECTRogram:NUMSLICEs? This query returns the number of spectrogram slices that are currently being rendered. A spectrogram slice is a section o f the s…
Command Groups
Table 2-37: RF Commands (cont.)
Item Description
RF:RF_AMPlitude:VERTical:
SCAle
This command specifies the vertical scale for the RF Amplitude vs. Time trace. For a signal
with constant amplitude, increasing the scale causes the waveform to be displayed smaller.
Decreasing the scale causes the waveform to be displayed larger.
RF:RF_AVErage:COUNt? This query returns the number of RF traces that have been accumulated to create a n RF
Average frequency domain trace.
RF:RF_AVErage:NUMAVg
This command specifies the number of acquisitions to be used when creating an RF Average
frequency domain trace, which displays the average of values from multiple acquisitions at
each trace point. The default is 16. The range is 2 – 512, in exponential increments.
RF:RF_FREQuency:LABel This command speci fies the label for the RF Frequency vs. Time trace.
RF:RF_FREQuency:VERTical:
POSition
This command specifies the vertical position for the RF Frequency vs. Time trace. The position
value determines the vertical graticule location at which the trace is displayed. Increasing the
position value of a waveform causes the w aveform to move up. Decreasing the position value
causes the waveform to move down. The minimum is -50 divisions and the m aximum is
50 divisions with a resolution of 0 .02 divisions.
RF:RF_FREQuency:VERTical:
SCAle
This command speci fies the vertical scale for the RF Frequency vs. Time trace. For a signal
with constant amplitude, increasing the scale causes the waveform to be displayed smaller.
Decreasing the scale causes the waveform to be displayed larger.
RF:RF_PHASe:LABel This command specifies the label for the RF Phase vs. Time trace.
RF:RF_PHASe:REFERence:
DEGrees
Sets or returns the phase, in degrees, at the trigger point for the RF_PHA Se time domain trace.
RF:RF_PHASe:VERTical:POSition This command specifies the vertical position for RF Phase vs. Time trace. The position value
determines the vertical graticule location at which the trace is displayed. Increasing the position
value of a waveform causes the waveform to m ove up. Decreasing the position value causes
the waveform to move down. The minimum is -50 divisions and the maximum is 50 divisions
with a resolution of 0.02 divisions.
RF:RF_PHASe:VERTical:SCAle This command specifies the vertical scale for RF Phase vs. Time trace. For a signal with
constant amplitude, increasing the scale causes the w aveform to be displayed smaller.
Decreasing the scale causes the waveform to be displayed larger.
RF:RF_PHASe:WRAP:DEGrees Sets or returns the number of degrees to wrap the RF_PHASe time domain trace.
RF:RF_PHASe:WRAP:STATE Sets or returns the state of the phase w rap control for the RF_PHASE time domain trace.
RF:RF_V_TIMe:BANDWidth
Sets or returns the RF versus time bandwidth as an NR3 value in Hz.
RF:SCAle This command specifies the overall vertical scale setting of the frequency domain w indow.
The lower limit is 0.1 dB/division. The upper limit is 100dB/division. The vertical scale is
adjustable in a 1–2–5 sequence.
RF:SPAN This command speci fies the span setting. The span is the range of frequencies that can be
observed around the center frequency. This is the width of the frequency domain trace, which
is equal to the stop frequency minus the start frequency. The span maximum varies according
to the oscilloscope model; e ither 3GHz or 6G Hz.
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 RB W Mode to AUTO, use the
command RF:RBW:MODe.)
RF:SPECTRogram Clears the spectrogram.
2-56 MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual
Command Groups
Table 2-37: RF Commands (cont.)
Item Description
RF:SPECTRogram:NUMSLICEs? This query returns the number of spectrogram slices that are currently being rendered. A
spectrogram slice is a section of the spectrogram representing oneinterval,orslice,oftime
in the spectrogram record.
RF:SPECTRogram:SLICESELect This command specifies the s pectrogram slice number that is to be displayed. Allowable
slice numbers range from 0 to –327 in full-screen mode, and 0 to –147 in split-screen mode.
(The range is negative because the numbering starts with the latest slice (0) and proceeds
backwards in time.) The slice can only be sel ected 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 running, are
ignored. The query form returns the currently selected spectrogram slice.
To use this command, 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 scroll “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.
RF:SPECTRogram:SLICETIMe? Returns the time stamp of the selected spectrogram slice, as specified by the command
:RF:SPECTRogram:SLICESELect.
RF:SPECTRogram:STATE This command switches the frequency domain spectrogram display on or off.
RF:SPECTRogram:TIMe? Queries the number of seconds in the spectrogram since continuous acquisition started. The
value returned is always <= 0.
RF:SPECTRUMMode When only the frequency domain waveforms are displayed, this command specifies the RF
spectrum mode: either
TRIGgered or FREErun. The default i s FREErun.
RF:SPECTRUMTrace
Resets the spectrum traces,
RF_MINHold, RF_MAXH old and RF_AVErage.
RF:SQUELCH:STAT E This command turns the squelch control on or off for the RF Frequency vs. Time and RF Phase
vs. Time traces. When squelch is on, only the portions of these traces where the amplitude
exceeds the squelch threshold are displayed. This prevents the display of Phase and/or
Frequency for signals that are at or near noise levels. The RF amplitude can be observed in
the RF Amplitude vs. Time trace.
RF:SQUELCH:THReshold This command speci fies the s quelch threshold level, in volts, for the RF Frequency vs. Time
and RF Phase vs. Time traces.
RF:STARt This command specifies to exclude frequencies below a certain level from use.
RF:STOP This command specifies to exclude frequencies above a certain level from use.
RF:UNIts
This command specifies the vertical units to be used in all RF-related absolute logarithmic
amplitudes.
RF:WINdow
This command speci fies which window will be used for the windowing function, which is only
used for the three time domain RF traces (Amplitude vs. Time, Frequency vs. Time and
Phase vs. Time). The default window is Kaiser.
MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual 2-57
Command Groups
Table 2-37: RF Commands (cont.)
Item Description
SEARCH:SPECTral:LIST? This query will return a list o f all automatically placed peak markers displayed in the frequency
domain graticule. (To return information about manual markers, use the MARKER:M<x>
commands.)
SELect:RF_AMPlitude This command switches the RF Amplitude vs. Timetracedisplayonoroffinthetimedomain
graticule.
SELect:RF_AVErage This command switches the R F Average trace display on or off in the frequency domain
graticule.
SELect:RF_FREQuency This command switches the RF Frequency vs. Time trace display on or off in the time domain
graticule.
SELect:RF_MAXHold This command switches the frequency domain Max Hold trace display on or off in the
frequency domain graticule.
SELect:RF_MINHold This command switches the frequency domain Min Hold trace display on or off in the frequency
domain graticule.
SELect:RF_NORMal This command switches the frequency domain Normal trace display on or off in the frequency
domain graticule.
SELect:RF_PHASe This command switches the RF P hase vs. Time trace display on or off in the time domain
graticule.
Save and Recall Command Group
UsethecommandsintheSaveandRecallCommand Group to store and retrieve
wav
eforms and settings. When you save a setup, you save all the settings of the
oscilloscope. When you recall a setup, the oscilloscope restores itself tothestate
it was in when you originally saved the setting.
NOTE. External filestructureisasfollows:
E: is the USB memory device plugged into the first USB port o n the front of the
oscilloscope.
F: is the USB memory device plugged into the second USB port on the front of the
oscilloscope. (Not available for MDO3000 models).
G: and H: are the USB memory device plugged into the USB ports on the rear o f
the oscilloscope. (Not available for MDO3000 models.)
I: — Z are for network storage.
2-58 MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual