Agilent Technologies J-BERT N4903A Getting Started page 9

Setting Up the Instrument
Synchronizing the Pattern
Now make sure that the error detector
automatically syncs to the data pattern:
1
Open the Pattern Sync
Setup dialog box.
2
Make sure that
Normal Sync Mode
and Automatic Sync
are selected.
Setting the Sampling Point
Now set the optimum sampling point:
1
Switch to the
Sampling Point Setup.
2
Press the Auto Align
to measure the eye diagram
and to position the sampling
point at the center of the eye.
This usually takes
about 10 seconds.
button
With this setting, the error detector starts
synchronizing when the BER exceeds a
certain threshold value. You can see when
it has synchronized when the
indicator goes off.
probably outside of the eye. You should proceed with
setting the sampling point anyway. As soon as the instrument
finds the eye, with the settings we just made, it will
automatically synchronize the patterns.
The BER indicator in the top left
corner displays the current BER
at this sampling point which
should be 0 for this test.
Sync Loss
If sync fails, the sampling point is
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