Huawei SmartAX MA5612 Maintenance Manual page 236

SmartAX MA5612 Multi-service Access Module
Maintenance Guide
Possible Cause
The optical fiber
connector is not clean.
NOTE
The optical fiber is bent
excessively.
NOTE
The optical fiber is not
firmly connected or
different types of optical
fiber connectors are
interconnected.
NOTE
The multi-mode optical
fiber is used as the
backbone or branch
optical fiber.
NOTE
Issue 01 (2012-07-25)
An unclean optical fiber
connector will cause
excessive attenuation and
abnormal reflection.
Optical signals attenuate
seriously on an optical
fiber with an excessively
small bending radius.
If the optical fiber is not
firmly connected or
different types of optical
fiber connectors are
interconnected, the
attenuation and reflection
will be excessively large.
If the multi-mode optical
fiber is used as the
backbone or branch optical
fiber, the optical signal
attenuates quickly and the
return loss increases.
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Judgment Criterion
1. Test the backbone fiber and
branch fiber by using the
OTDR. It is found that the
reflection and return loss
are abnormal.
2. Check the optical fiber
connector on site by using
the optical fiber endface
detector. It is found that the
optical fiber connector is
not clean.
1. Test the backbone fiber and
branch fiber by using the
OTDR. It is found that
abnormal return loss points
exist on the optical fiber.
2. Check the optical fiber on
site. It is found that the
optical fiber is bent
excessively.
1. Test the backbone fiber and
branch fiber by using the
OTDR. It is found that
abnormal return loss points
exist on the optical fiber.
2. Check the optical fiber
connectors on site. It is
found that the optical fiber
is not firmly connected or
PC connector (blue) and
APC connector (green) are
interconnected.
1. Check the backbone fiber
and branch fiber by using
the OTDR. It is found that
optical signals attenuate
seriously.
2. Check the optical path on
site. It is found that the
multi-mode optical fiber is
used. The multi-mode
optical fiber can be
recognized by its physical
features such as its color.
6 System Fault Handling
Troubleshooting Method
Clean the optical fiber
connector. For details about
how to clean the connector, see
2.2 Cleaning the Connector of
the Optical Fiber.
Route and bundle the optical
fiber in a proper manner.
l If the optical fiber is not
firmly connected, reconnect
the optical fiber firmly.
l If different types of optical
fiber connectors are
interconnected, replace the
incompatible connector
with a compatible one or
replace relevant devices,
such as the optical splitter.
NOTE
In the scenario of the CATV
service, it is recommended that
you use APC connectors (green)
only.
Replace the multi-mode optical
fiber with the single-mode
optical fiber.
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