Anritsu BERTWave MP2100B, Руководство по эксплуатации, Страница: 50 / 382

Chapter 1 Outline
1-20
Rise/Fall Time
The Rise Time is time taken for the signal level to change to the next
level.
 From 20% level of amplitude to 80%
 From 10% level of amplitude to 90%
The Fall Time is the time taken for the signal level to change to the next
level.
 From 80% level of amplitude to 20%
 From 90% level of amplitude to 10%
For the BERTWave, the rise and fall time measurement level can be
selected from either 10/90% or 20/80%.
Rise Time
*1
*2
"0" Level
"1" Level
Eye amplitude
Fall Time
*1: 90 or 80 % *2: 10 or 20 %
Figure 1.5-10 Rise and Fall Time
Total Error
There are two methods as follows for generating bit errors.
The following bit error count corresponding to the sum of Insertion Error
and Omission Error is referred to as the Total Error.

Signal “1” bits evaluated as “0” bits (Omission Error)
 Signal “0” bits evaluated as “1” bits (Insertion Error)
Optical Modulation Amplitude (OMA)
This indicates a difference at 1 level and 0 levels of the optical waveform.
It is the same as Eye Amplitude.