EXFO FTB-7000 OTDR for FTB-200 v2 - Manual (Page 260)

Analyzing Traces with the Bidirectional Analysis Application
246 FTB-7000 Series
Saving the Span-Start and Span-End Information
Saving the Span-Start and Span-End
Information
Saving the modified span-start and span-end information allows you to
reapply the current span start and span end to a unidirectional trace when
your reanalyze this trace.
To save the span-start and/or span-end information or to
deactivate the feature:
1. From the Main Menu, select Setup, then select the Events tab.
2. Select the Keep span start current position and/or the
Keep span end current position boxes.
OR
If you prefer not to save the span positions, clear the boxes.
3. Press Apply to confirm the changes, then OK to return to the main
window.