ControlNet Fiber Media
Checking fiber optic cable measurements
22
Experion PKS ControlNet Fiber Optic Implemenation Guide
R210
Honeywell
10/04
Checking fiber optic cable measurements
Measuring power loss
You can use an optical power source and power meter to check that the attenuation in
your fiber cable sections is less than 9.3 dB. Optical power sources send light through
one end of a fiber cable section to be measured on an optical power meter at the other
end. This lets you confirm the viability of a given cable section.
It is a good idea to keep a record of the attenuation levels for each cable section. These
records can be helpful in troubleshooting and maintaining your network.
The following is a list of possible causes for high attenuation or considerable power loss
in a cable section.
•
Poor splices
•
Bending losses
•
Broken fibers
•
Poor connections
•
Contaminated or damaged connectors
Measuring OTDR
In addition to measuring power loss, you should check your total fiber network using an
Optical Time Domain Reflectometer (OTDR). The OTDR transmits light into a strand of
fiber optic cable and displays the reflected light. This data will help you determine the
following about your fiber network.
•
Total distance along the cable to a fiber break.
•
Distance to an event (splice, bend, connector) that attenuates the light.
•
Distance between two attenuating events.
•
Light attenuation between two points of the cable.
•
Total reflected light or light reflected from a single event.
