Users Manual Owner manual

Chapter 12: How to Diagnose Problems in Fiber Links
Causes of OTDR Test Failures
295
Fiber length fails or the length is incorrect
 The fiber is broken or there is an open connection where the trace
shows the fiber end.
 The wrong fiber type is selected on the TEST SETUP screen.
 The index of refraction needs adjustment. To change the IOR setting,
tap Fiber Type Settings on the TEST SETUP screen.
 The wrong test limit is selected on the TEST SETUP screen.
The overall result is FAIL, but no event shows FAIL, or an event shows FAIL,
but does not exceed any limit
 Some conditions make the OTDR test fail even when all measurements
are within the limits. For example, the test fails if Launch + Tail
compensation was enabled, but you did not connect a tail cord. These
conditions show as warnings when the test is completed. To see
warnings caused a FAIL result, tap on the OVERALL FIBER RESULT
screen (see Figure 110 on page 255).
 The test limit includes a limit for the attenuation coefficient, and the
attenuation coefficient of the fiber segment before an event is too
high. To see the attenuation coefficient for the segment before an
event, tap the event on the EventMap screen, tap the information
window for the event, then tap the SEGMENT ATTENUATION tab on
the EVENT DETAILS screen.
(continued)
Table 15. Causes of OTDR Test Failures (continued)