VeEX FX150, User Manual

Page: 68 / 128

OTDR Series e-Manual, RevE00 Page 68 of 128
•
Distance range (km, m, miles, kilofeet, ft): maximum value of measured distances;
the value of distance range should exceed the expected length of the fiber under test
(20% more). The distance unit type can be set by clicking the Display button (FX150) or
selecting the unit in the Distance Unit drop-down (RXT-4111/RXT-4113).
•
Pulse Width, ns : the value of the optical pulse duration; the range of available optical
pulse values depend on the selected distance range and is set by the OTDR software
automatically (10 ns pulse ~ 1 meter). Short pulse widths provide better resolution and
produce the best event and attenuation dead zones. Short pulse widths, however, inject
less optical energy into the Fiber-Under-Test (FUT), resulting in a noisier trace and
lower dynamic range. Longer pulse widths provide the highest dynamic range and are
used to test long fibers.
•
Resolution, m
: distance between two data points (sampling interval) of the trace;
values depend on the selected distance range. Select smallest value to measure events
spaced close together and use largest value to for longer ranges. Auto mode will deter-
mine best value for Fiber Under Test.
•
Time, min:sec : determines the duration of measurement process with averaging. Use
Live mode to perform monitoring of the fiber in Real Time. Longer averaging time
improves the SNR and produces a “smoother” trace.
• Optimized For: test modes - Automatic DR/DZ, maximize dynamic range (DR mode) or
best deadzone, sacrifice range (DZ mode)
7.2.2 Auto Mode
To set OTDR test parameters automatically, under
Test Parameters
select
Auto
from the
Mode drop-down box. In this mode, the OTDR performs a measurement and analysis of the
fiber and determines optimal test settings automatically.
OTDR Setup: FX150 Auto mode