User guide

• Number of Errors
After this number of errors, the measurement stops for the current sample point
and moves to the next one. This allows you to speed up the measurement. You
can switch off this option if only the number of compared bits is important.
N O T E
The measurement moves to the next sample point when the first of the two criteria
is reached.
Both numbers are ignored if the Fast Total Jitter measurement is selected.
Set the criteria for the sample delay:
• Resolution
Specifies the time distance between sampling points. A smaller value yields
more sampling points in a unit interval. You can enter the resolution in UI or
ps, ns, s, .... The timebase of the display is set on the View tab.
If the resolution used for the measurement is not high enough, the bathtub
curve does not clearly show the edges. For example, you may wish to change
the Resolution from 0.01 to 0.005 and run the measurement again.
• Optimization
You can choose between Edge Resolution Optimization, Fast Total Jitter at
BER, or None.
– Edge Resolution Optimization
Turns the resolution optimization on or off. If this option is enabled, the
Serial BERT intelligently sets a resolution so that there are more sampling
points at the edges. This can greatly improve the results without
dramatically increasing the duration of the test.
The following illustration shows a diagram with default resolution and no
edge resolution optimization:
The following illustration shows a diagram with high resolution and edge
resolution optimization. For the areas of the diagram with edges, additional
sampling points are taken, resulting in a much better display of the signal
shape:
Advanced Analysis 6
Agilent J-BERT N4903B High-Performance Serial BERT 253