EXFO OTDR 2 - Manual (Page 26)

Preparing Your OTDR for a Test
18 OTDR
Naming Trace Files Automatically
Naming Trace Files Automatically
Each time you start an acquisition, the application suggests a file name
based on autonaming settings. This file name appears at the bottom of the
window.
The file name is made of one or more static parts (alphanumeric) and one
or more variable parts (numeric) that will be incremented or
decremented, according to your selection, as follows:
Note: To decrement values, the start number must be higher than the stop
number.
After saving a result, the unit prepares the next file name by incrementing
(or decrementing) the suffix.
If you choose incrementation... If you choose decrementation...
Variable part increases until it
reaches the highest possible value
with the selected number of digits,
then restarts at 1.
Variable part decreases until it
reaches 1, then restarts at the highest
possible value with the selected
number of digits.