Operation Manual

Using the OTDR Module
Looking at OTDR Test Results
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7
Table 7-3. Event Types
-continued-
Event Possible Causes
OTDR Port
The tester’s OTDR port
connector.
The tester identifies the OTDR port connection and grades its quality, as shown on
the OTDR details screens. See “OTDR Port Connection Quality” on page 7-21.
Reflection
A pulse of light reflected back
to the OTDR.
Caused by a connector, tight bend, or crack in the fiber. Small reflective events may
actually be ghosts.
If the reflection is not caused by a connector, inspect the cable for tight bends or
damage. Use the visual fault locator to verify the fault. See Chapter 9.
Loss
A point where the level of
reflected light suddenly
decreases.
Caused by a splice or bend.
If the loss event is not caused by a splice, inspect the cable for tight bends. Use a
visual fault locator to verify the fault.
Launch Event
The end of the launch fiber.
Receive Event
The beginning of the receive
fiber.
The tester identifies these events if launch and receive fibers are connected and
Launch Compensation is enabled in Setup. See “Compensating for Launch and
Receive Fibers” on page 7-12 for more information.