Download Agilent N4901 Serial BERT

Clock Setup
Setting up the Error Detector
Auto Threshold
If the Auto Threshold option is selected, the Serial BERT continuously
analyzes the incoming data stream to detect the voltage level that is
optimal for the derivation of the clock signal.
This function is recommended for all applications where a valid data
stream is continuously arriving at the error detector.
For measurements with partly invalid data, such as burst tests, this
function may cause a clock loss. In such cases, deactivate Auto
Threshold and
• enter a fixed voltage level manually, or
• press the Measure button to measure the voltage level of the
incoming signal while a burst signal is applied.
Once the level is defined, it remains fixed for the following
measurements.
Note that the entered voltage level has to be within the input range of
the error detector. If the value lies outside this range, the change is
rejected and an error message is displayed.
Agilent Serial BERT N4901/2, User’s Guide, January 2006
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