EXFO FTB-7000 OTDR Series for FTB-500 - Manual (Page 213)

OTDR 199
11 Managing Trace Files
Once you have acquired traces, or when you want to work with them after
an acquisition, you will need to save, open, rename, and delete trace files.
Saving a Trace in a Different Format
By default, the application saves the traces in EXFO format (.trc). However,
you can configure the application to save traces directly in other formats
(see Selecting the Default File Format on page 109).
For a list of file formats that can be loaded, modified or reanalyzed with the
application, see Opening Trace Files on page 179.