EXFO FTB-7000 OTDR for FTB-200 v2 - Manual (Page 251)

Analyzing Traces with the Bidirectional Analysis Application
OTDR 237
Changing the Attenuation of Fiber Sections
Changing the Attenuation of Fiber Sections
Note: You can only modify the sections of the A->B or B->A trace (not those of
the bidirectional measurement). The application regenerates the
bidirectional measurement automatically to take into account the
modifications you have made.
You can change the attenuation value of fiber sections.
Note: If you want to modify events, see Modifying Events on page 231.
I
MPORTANT
If you reanalyze a trace, all of the modifications made to the fiber
sections will be lost and the events table will be re-created.