EXFO FG-750 - Manual (Page 163)

Operating Your RTU in OTDR Measuring Mode
Fiber Guardian 149
Managing Optical Routes
You can either select one of the predefined threshold sets (default or
your own) or set the parameters manually. For information on how to
create your own threshold sets, see Managing Threshold Sets on
page 162.
If, after performing tests, you find that the fault detection is too
sensitive, you can do one of the following:

Select a less sensitive threshold set.

Create a threshold set with custom values, and select it in the test
setup. In this case, you will also need to perform a new reference.

You can specify which data will be uploaded to the EMS server (not
applicable when RTU is used in stand-alone mode). For more
information, see Defining Default Values for System Parameters on
page 135.
Normal is selected by default, but you can set the application to use
another option by default (see Managing System Setting Values on
page 127).

You can define parameters for the learning process.
A learning phase is a key provisioning function in NQMSfiber. This
function provides information about the fiber under test. It creates a
series of statistics on the stability of the link loss and every event of the
fiber reference trace. Stable events or sections can then be monitored
more closely. The less stable events, such as the very far end portion of
the trace, are obtained from the system with the best possible fault
detection thresholds. The learning process consists of at least one
cycle during which the application will perform the specified number
of acquisitions to establish the fault detection parameters (limits, mean
value). These parameters take into account the environmental
variations occurring on the fiber during the learning process.
The first reference is created when you apply the changes from the
RTU configuration window (gear icon). If a first reference has been
created already, you can also create a new first reference using the