EXFO FG-750 - Manual (Page 162)

Operating Your RTU in OTDR Measuring Mode
148 FG-750
Managing Optical Routes

You can either set the acquisition parameters (range, pulse, duration)
yourself or let the application determine the most appropriate values.
In the latter case, the application will automatically evaluate the best
settings according to the fiber link currently connected to the unit.

To optimize event detection, you can set the following analysis
detection thresholds:

Splice loss threshold: To detect small non-reflective events during
trace analysis.

Reflectance threshold: To detect small reflective events during
trace analysis.

End-of-fiber threshold: To detect important event loss that could
compromise signal transmission during trace analysis.

If you select the Extended mode (peak detection) option, the
application will search the “noisy” portion of the OTDR trace to detect
strong reflective events (such as those caused by UPC connectors) and
set the monitoring range up to this point. The reflective peak level will
be used as an indicator for link loss between end of fiber (RBS) and
this point.
Note: The application will take the option into account only if there is a significant
reflective event located after the end of analysis.

You can set the fault detection thresholds. The application uses these
thresholds when comparing the current measurement with reference
trace to determine if there is a fault or not.
I
MPORTANT
EXFO does not recommend to test in high resolution if the
acquisition time is less than 15 seconds. It may be impossible to
obtain acceptable performance with this combination of settings.