MDO3000 Programmer Manual.pdf - 第618页
Commands Listed in A lphabetical Order Examples RF:SQUELCH:ST ATE ON turns the squelch control on. RF:SQUELCH:ST ATE? might return 0, indicating that squelch has been turned off. RF:SQUELCH:THReshold This command specifie…

Commands Listed in Alphabetical Order
Arguments
TRIGgered ties
RF acquisitions to the scope's unified triggering system for all
channels.
FREErun acqui
res RF data as often as processing allows, without waiting for
trigger events.
Examples
RF:SPECTRUMMode TRIG sets the RF spectrum mode to TRIGgered.
RF:SPECTRUMMode? might return FREERUN, indicating the spectrum mode
is free run, the default.
RF:SPECTRUMTrace (No Query Form)
Resets the spectrum traces, RF_MINH old, RF_MAXHold and RF_AVErage.
Group
RF
Syntax
RF:SPECTRUMTrace {RESET}
Examples
RF:SPECTRUMTRACE RESET resets the spectrum traces: RF_MINHo ld,
RF_MAXHold and RF_AVErage.
RF:SQUELCH:STATE
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.
Conditions
MDO4000/B/C models only.
Group
RF
Syntax
RF:SQUELCH:STATE {OFF|ON|0|1}
RF:SQUELCH:STATE?
Related Commands
RF:SQUELCH:THReshold
MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual 2-587

Commands Listed in Alphabetical Order
Examples
RF:SQUELCH:ST
ATE ON
turns the squelch control on.
RF:SQUELCH:STATE? might return 0, indicating that squelch has been turned off.
RF:SQUELCH:THReshold
This command specifies the squelch threshold level, in volts, for the RF Frequency
vs. Time and RF Phase vs. Time traces.
Conditions
MDO4000/B/C models only.
Group
RF
Syntax
RF:SQUELCH:THReshold <NR3>
RF:SQUELCH:THReshold?
Related Commands
RF:SQUELCH:STATE
Arguments
<NR3> is a floating point number.
Examples
RF:SQUELCH:THReshold 200.0000E-6 sets the squelch threshold level to
200 μV.
RF:SQUELCH:THReshold? might return 22.0000E-6, indicating the squelch
threshold level is 22 μV.
RF:STARt
This command specifies to exclude frequencies below a certain level from use.
NOTE. For the parameters RF:STARt, RF:STOP, RF:FREQuency and RF:SPAN,
when any one of the parameters is changed, the following relationship is enforced:
START = FREQ — SPAN/2
STOP = FREQ + SPAN/2
FREQ = (START + STOP)/2
SPAN = STOP — START
Conditions
MDO3000, MDO4000/B, or MDO4000C models with option SA3 or SA6 only.
2-588 MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual

Commands Listed in Alphabetical Order
Group
RF
Syntax
RF:STARt <NR3>
RF:STARt?
Arguments
<NR3> is a floating point value that represents the Start frequency.
Examples
RF:STARt 0 specifies to exclude frequencies below 0 Hz from use.
RF:STARt? might return 0.0E+0, indicating that the Start frequency is 0 Hz.
RF:STOP
This command specifies to exclude frequencies above a certain level from use.
NOTE. For the parameters RF:STARt, RF:STOP, RF:FREQuency and RF:SPAN,
when any one of the parameters is changed, the following relationship is enforc
ed:
START = FREQ — SPAN/2
STOP = FREQ + SPAN/2
FREQ = (START + STOP)/2
SPAN = STOP — START
Conditions
MDO3000, MDO4000/B, or MDO4000C models with option SA3 or SA6 only.
Group
RF
Syntax
RF:STOP <NR3>
RF:STOP?
Arguments
<NR3> is a floating point value.
Examples
RF:STOP 3.0000E+9 specifies to exclude frequencies above 3 GHz from use.
RF:STOP? might return 3.0000E+9, the default.
MDO4000/B/C, MSO/DPO4000B and MDO3000 Series Oscilloscopes Programmer Manual 2-589