Teledyne LeCroy SDA II - Manual (Page 25)

Operator's Manual
This measurement algorithm is best suited to eye diagrams that are rendered from optical rather than
electrical signals. In the presence of inter-symbol interference and/or equalization, it may not give rea-
sonable results.
The Q factor is a measure of the overall signal-to-noise ratio of the data signal. It is computed by taking
the eye amplitude (the difference between the mean values of the 1 and 0 levels) and dividing it by the
sum of the noise values (standard deviations of the 1 and 0 levels).
All of these measurements are taken in the center (usually 20%) of the eye. Users can show the Q factor
via the Measure system.
Mask Hits
Number of samples where the signal impedes the mask.
Mask Out
Number of samples where the signal does not impeded the mask.
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