Agilent Technologies J-BERT N4903, User Manual

Page: 229 / 434

Eye Opening - Reference
The Eye Opening measurement returns the results in a graphical and in
a numerical form. The following sections provide explanations of the
measured parameters and the display options that are specific to this
measurement. Additionally, some information is provided to explain
the theoretical background behind.
Properties that can be specified on the various tabs of the Properties
dialog box:
Parameters Tab
N O T E
If you modify the parameters on this page, you have to rerun the measurement to
update the results.
Set the criteria for moving to the next sample point:
•
Number of Compared Bits
After this number of compared bits, the measurement stops for the
current sample point and moves to the next one.
The default is 1 million bits. That means, you can measure a bit error
rate down to 10
-6 (one error per million).
A smaller number reduces the duration of the whole Eye Opening
measurement. A larger number increases the precision of the
measured bit error rates.
•
Number of Errors
After this number of errors, the measurement stops for the current
sample point and moves to the next one. Thisallows 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.
Set the criteria for the sample delay:
•
Resolution
Specifies the distance between sampling points. The lower this value,
the more sampling points you have 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.
Advanced Analysis
5
Agilent J-BERT N4903 High-Performance Serial BERT 229