EXFO FTB-5600 Distributed PMD Analyzer - Manual (Page 53)

Setting up and Operating your Distributed PMD Analyzer
Distributed PMD Analyzer 47
Using the Bidirectional File Creator
9. Select the appropriate PMD resolution from the list.
A summary of the parameters is displayed on-screen.
10. Press Start.
The acquisition starts. You can see the remaining time and number of
SOPs in the status bar.
Using the Bidirectional File Creator
Since PMD accumulates in quadratic manner, the higher the PMD, the
more difficult it is to measure weak PMD variations. Using a measurement
coming from each end of the link you want to characterize and combining
the two measurements into one bidirectional trace file can help you
improve the precision of the measurement all over the link.
When measuring links that are too long for the dynamic range of the unit,
creating a bidirectional trace by combining the traces coming from each
end doubles the effective measurement range.
The files can therefore overlap fully, partly, or not overlap at all.
Note: You cannot use a bidirectional file you have already created to create a
new bidirectional file.