User guide

Cancel
Click this button to cancel the Auto Align, 0/1 Threshold Center, or Data Center
functions while they are in progress. The following parameters will be returned to
their previous value or status:
• Auto Align Canceled
– Data Delay and 0/1 Threshold values returned to previous.
– Status of Data Inverted and Avg. 0/1 Threshold checkboxes returned to
previous.
• 0/1 Threshold Center Canceled
– 0/1 Threshold value returned to previous.
– Status of Avg. 0/1 Threshold checkbox returned to previous.
• Data Center Canceled
– Data Delay value returned to previous.
BER Threshold
In this list, select an alignment BER threshold that is appropriate for your
application.
The alignment BER threshold is the pre-defined threshold used by the Data
Center, 0/1 Threshold Center, and Auto Align functions to define the edges of the
data input eye in the time and voltage axes. You may wish to change the threshold
for the following reasons:
• Choosing smaller alignment BER thresholds will cause the auto-search
functions to set more accurate sampling points. However, if the BER threshold
is set lower than the residual BER of the measurement, the auto-search
functions will fail. 1E-7 is the smallest BER threshold available.
• Running the auto-search functions and viewing eye results at different BER
thresholds will allow you to see the eye margin at specific BERs. You can also
construct basic eye contour information.
Avg. 0/1 Threshold
Activate this checkbox to make the error detector continuously set the 0/1
threshold level to the average DC voltage level of the incoming data signal.
N O T E
Manual 0/1 threshold changes are impossible while this function is selected.
Setting up the Error Detector 5
Agilent J-BERT N4903B High-Performance Serial BERT 201