:CMODe:SNOise:CALibrate

:CMODe General Commands

Command Syntax

:CMODeN:SNOise:CALibrate

Where N identifies a specific common-mode waveform in the form "<connection1-8>_<ch1|ch3|ch5|ch7>". With connection 1, the connection number part (that is, "1_") is optional, and you can simply use the channel number "<ch1|ch3|ch5|ch7>". When two channels are paired to create a differential waveform and a common-mode waveform, the odd-numbered channel is used when specifying the waveform. For example, connection 5 common-mode waveform 3 (from the pairing of channels 3 and 4) is CMODe5_3.

Description

This command starts the oscilloscope noise calibration on the specified input channel.

This command is the same as clicking the Calibrate Scope jitter/noise button in the graphical user interface.

By measuring the oscilloscope noise and slew rate, the oscilloscope is able to calculate the oscilloscope's contributions to jitter and noise and remove it from the reported RJ and RN measurements.

Automatic calibration of oscilloscope noise works by measuring the AC Vrms two divisions up from center screen for the one level and two divisions down from center screen for the zero level. These values can be removed from the reported one and zero RN and TN. The oscilloscope's measured RN is also reported in the noise results.

You will be asked to remove your probe from the oscilloscope's input while calibration takes place and to reconnect your probe when finished.

Recalibrate Oscilloscope Jitter/Noise When Settings Change

When the oscilloscope's calibrated jitter or noise is used in measurements and any of the following settings changes, the oscilloscope jitter or noise should be recalibrated:

  • Sample rate (Manual or Automatic)
  • Global bandwidth limit state or value
  • Channel bandwidth limit state, type, or value
  • Channel vertical scale
  • De-embedding state
  • Equalization state or location
  • Signal type

A reminder message appears when the oscilloscope detects settings changes. However, the oscilloscope detects changes during a session only (and not between Infiniium application restarts), so be aware when these settings changes happen outside of a session.

Use the :SNOise:CALibrate:SDONe? command to check the status of the oscilloscope noise calibration.

Use the :SNOise:CALibrate:CONTinue command to continue with the oscilloscope noise calibration after a pause in the procedure, for example, to disconnect channel inputs.

Use the :SNOise:CALibrate:CANCel command to cancel the oscilloscope noise calibration.