EXFO FTB-7000 OTDR for FTB-200 v2 - Manual (Page 232)

Analyzing Traces with the Bidirectional Analysis Application
218 FTB-7000 Series
Modifying the Alignment of Unidirectional Traces
You can even set the span end after the detected end of fiber. This could be
useful if you suspect problems in this section of the trace or if the actual
end of fiber seems to be located in the noise (peak detected at the end of
the fiber span). The end of fiber will be moved accordingly. However, if you
move the span end back within the original fiber span, the end of fiber will
remain at its current location (it will not be moved back with this new span
end).
The application will refresh the graph to reflect the new span start and
span end positions automatically.
I
MPORTANT
If you reanalyze a trace, the position of the fiber end will be reset
and the events table will be re-created.