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When automatic reference selection is ON, the first measurement made is used as the null value for all
subsequent measurements.
[SENSe:]{FREQuency|PERiod}:NULL:VALue
is set to this value. Automatic
null value selection will be disabled.
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When automatic null value selection is disabled (OFF), the null value is specified by:
{FREQuency|PERiod}:NULL:VALue.
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The instrument enables automatic null value selection when the null function is enabled (
{FREQuency|PERiod}:NULL:STATe ON
).
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This parameter is set to its default value after a Factory Reset (
), Instrument Preset
(
), or CONFigure function.
[SENSe:]{FREQuency|PERiod}:RANGe:LOWer {<
freq
>|MIN|MAX|DEF}
[SENSe:]{FREQuency|PERiod}:RANGe:LOWer? [{MIN|MAX|DEF}]
Sets the AC bandwidth used to detect the signal during frequency and period measurements.
This parameter is shared between frequency and period measurements. Setting or querying the parameter
with the FREQuency version of this command is identical to setting or querying it with the PERiod version.
The instrument uses three different AC filters that enable you either to optimize low frequency accuracy or
to achieve faster AC settling times following a change in input signal amplitude. The instrument selects the
slow (3 Hz), medium (20 Hz) or fast (200 Hz) filter based on the cutoff frequency specified by this com-
mand. Specify the lowest frequency that you expect to encounter.
Parameter
Typical Return
{3 Hz|20 Hz|200 Hz}. Default: 20Hz.
+6.2703
Make and read a frequency measurement. Use the 3 Hz filter bandwidth:
CONF:FREQ
FREQ:RANG:LOW 3
READ?
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If you enter the lowest expected frequency that you intend to encounter, the command will select the
appropriate <
filter
>. For example, if you enter 15 Hz, the slow filter (3 Hz) is selected. If you enter 190
Hz, the medium filter (20 Hz) is selected to provide the appropriate low cutoff.
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Set the lowest frequency that you expect to encounter. Lower bandwidths result in longer settling
delays, as shown:
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Input Frequency
Default Settling Delay
3 Hz - 300 kHz (
Slow
)
1.66 s/measurement
20 Hz - 300 kHz (
Medium
) 0.25 s/measurement
200 Hz - 300 kHz (
Fast
)
0.025 s/measurement
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This parameter is set to its default value after a Factory Reset (
) or Instrument Preset
(
).
SCPI Programming Reference
340
Keysight True
volt
Series Operating and Service Guide
