Monitoring the S
DI Physical Layer
To Manually Measure Aberrations
1. Perform the initial setup for Eye
measurements. (See page 65, Tak in g
Eye Measurements .)
2. Press the CURSOR button to display the
measurement cursors.
3. Position one voltage cursor at the peak
of the overshoot at the top horizontal part
of the waveform.
4. Position the second voltage cursor
at the bottom of the top line of the
waveform. Include any ringing (the
oscillation following overshoot) in the
measurement. Essentially, you are
measuring the thickness of the top line of
the waveform.
5. Note the amplitude of the aberration
displayed in the Voltage Cursor readout.
6. Perform the same voltage-cursor
measurement on the bottom line
thickness, including any undershoot and
ringing.
NOTE. Aberrations at the top or bottom line
of the waveform should not exceed 10% of
the signal amplitude. Automatic equalizer
circuits in receivers may be sensitive to
larger aberrations.
Waveform Monitors Quick Start User Manual 67