EXFO FG-750 - Manual (Page 147)

Setting Up Your RTU
Fiber Guardian 133
Managing System Setting Values
Defining Default Values for Test Setups
You can define, for monitoring and proactive maintenance (two distinct
sets of parameters), test settings such as resolution, acquisition type
(automatic or manual), range, etc. and learning settings such as the
targeted learning count, reset and expand parameters.

Resolution: By selecting the high-resolution feature (“high”), you will
obtain more data points per acquisition. This way, the data points will
be closer to each other, which will result in a greater distance
resolution for the trace.

Acquisition settings: With automatic settings, the application will
determine the most appropriate range, pulse width and duration for
you. If you prefer to specify these values yourself when you define a
test setup, you should select the manual settings.

Range: Corresponds to the distance range of the fiber span to be
tested, in kilometers.

Pulse width: A longer pulse allows you to probe further along the fiber,
but results in lower resolution. A shorter pulse width provides higher
resolution, but less distance range.

Duration: Corresponds to the acquisition duration (period during
which results will be averaged). Generally, longer acquisition times
generate cleaner traces (this is especially true with long-distance
traces) because as the acquisition time increases, more of the noise is
averaged out. This averaging increases the signal-to-noise ratio (SNR)
and the OTDR’s ability to detect small events.