EXFO FTB-7000 OTDR Series for FTB-500 - Manual (Page 256)

Analyzing Bidirectional Traces
242 OTDR
Changing Event Tables
Changing Event Tables
You can change event tables and edit the A->B and B->A traces.
If you change events in one event table, the bidirectional event table will be
adjusted accordingly.
If an event is detected in one direction but not in the other, it will
automatically be inserted by the utility at the location most likely to
designate an event within the default tolerance interval; the current loss
measured before an average bidirectional loss will be calculated.
To change event tables and edit the A->B or B->A trace:
Press the corresponding direction button (Table A->B or Table B->A) and
then press the Change button.
For more information, see Analyzing Traces and Events on page 129.