Keysight x-series Instruction Manual

4 System
4.6 Alignments
(similar to pressing the Restart key). The characterization takes many minutes to
run.
The noise floor model used by Noise Floor Extensions includes an estimation of the
temperature behavior of the noise floor, but this is only an estimation. The noise
floor changes little with the age of the components. However, even small changes in
the estimated level of the noise floor can make large changes in the effective noise
floor, because the effective noise floor is the error in the estimation of the noise
floor. Keysight recommends that the Characterize Noise Floor operation be
performed when the instrument is operating at an ambient temperature that is
significantly different than the ambient temperature at which this alignment was last
run. In addition, Keysight recommends that the Characterize Noise Floor operation
be performed after the first 500 hours of operation, and once every calendar year.
The noise floor model from the last operation of Characterize Noise Floor survives
across the power cycle.
NOTE
The Characterize Noise Floor function can be interrupted, by pressing the
Cancel (ESC) front-panel key, or remotely with Device Clear followed by the
:ABORt SCPI command. None of the new characterization data is then used.
However, since the old characterization data is purged at the beginning of the
characterization, you now have an uncharacterized noise floor. You should re-
execute this function and allow it to finish before making any further
measurements with NFE. Until you do, the instrument will display a
“Characterize Noise Floor required” message and set bit 12 in the Status
Questionable Calibration register
(STATus:QUEStionable:CALibration:EXTended:NEEDed).
Remote Command
:CALibration:NFLoor
:CALibration:NFLoor?
Example
:CAL:NFL
Notes :CALibration:NFLoor? returns 0 if successful, or 1 if failed (including interfering user signal)
This command is sequential; it must complete before further commands are processed. Interrupting
the alignment from remote is accomplished by invoking Device Clear followed by the :ABORt
command
Dependencies This control does not appear in models that do not contain NF2. In these models the command is
accepted without error, but no action is taken
Couplings Successful completion of Characterize Noise Floor begin the elapsed time counter or the Last Charac-
terize Noise Floor Time
Remote Command
:CALibration:TIME:NFLoor?
Example
:CAL:TIME:NFL?
Notes Value is the date and time the last successful Characterize Noise Floor was executed. The date is
separated from the time by a space character
Returns “” if no Characterize Noise Floor has ever been performed on the instrument
Short Range Comms & IoT Mode User's &Programmer's Reference 1848

Keysight x-series Specifications

General

Analysis Bandwidth	Up to 1 GHz (depending on model)
Real-Time Bandwidth	Up to 1 GHz (depending on model)
Form Factor	Benchtop
Connectivity	LAN, USB, GPIB
Resolution Bandwidth	1 Hz to 10 MHz (depending on model)