OMA at Crossing

Flex Apps:
FlexDCA
Meas. mode:
Eye
Waveform type:
NRZ
PAM4/6/8
Eye Mode
Eye Meas Toolbar

The Eye mode OMA at Crossing measurement measures the Optical Modulation Amplitude (OMA) at the eye diagram's crossing points which is Level 0 and Level 1 on NRZ waveforms. On PAM waveforms the crossing points are located at the Level 0 and the highest Level 3 for PAM4, Level 5 for PAM6, and Level 7 for PAM 8. As shown in the following picture of an NRZ waveform, two histogram windows are placed in time at the eye's crossing points, which occurs at adjacent one and adjacent zero levels. The resulting histogram gives the mathmatical mean of the one power level (P1) and mean of the zero power level (P0) in μW. OMA is the difference between the two means.

For an OMA measurement that is designed for NRZ patterns that use consecutive ones and zeros as is called out in standards, use Oscilloscope mode's OMA measurement.

This measurement applies to NRZ waveforms and PAM4, PAM6, and PAM8 waveforms.

Configurable Measurement Parameters

This measurement is affected by the following setting (click Measure > Configure Base Measurements):

To measure

  1. Select Eye/Mask Mode.
  2. Click the toolbar's Eye Meas tab.
  3. Click Auto Scale in the menu bar.
  4. Click the More buttons to locate the OMA at Crossing button.
  5. Click the button.

SCPI Command

:MEASure:EYE:OMAXp