Kongsberg M3 Sonar FLS, Installation Manual

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Ethernet cable installation
All cable connections may have to be made in accordance with the guidelines laid down by
the local electrical code.
Alien crosstalk
Alien crosstalk is where the signal from one cable interferes with the signal being carried by
another. This type of crosstalk resembles noise and reduces the quality of the communication
link. Alien crosstalk can occur when multiple Ethernet cables are coiled on a spool, looped,
or bundled together running long distances. Unlike other crosstalk that takes place within
the cable, alien crosstalk cannot be eliminated using phase cancellation. Alien crosstalk is
more of a problem at high data rates such as 1000BaseT or higher.
Here are some suggestions for avoiding alien crosstalk.
• Avoid tightly bundling cables together in parallel over long distances.
• Avoid using tie wraps to bundle cables together. Try to separate cables as much as
possible. If tie wraps are used, do not overtighten. Velcro cable wraps are recommended
instead of tie wraps and can easily be reused if rearranging the cables.
• Use Category 6A cable. This type of cable has a special core wrap that isolates and
protects the core from alien crosstalk.
Cable termination
Depending on your deployment method, you may need to terminate your Ethernet cables.
Terminating Ethernet cables is very precise work. To avoid impacting telemetry quality,
take note of the following problem areas.
• The parallel location of wires in the RJ45 connector forms a capacitive plate that is
a source for signal coupling or crosstalk.
• Untwisting the cable pairs increases the cable’s susceptibility to crosstalk interference.
• The cable crimping process can crush the conductor pairs and cause crosstalk interference.
Here are some suggestions to ensure optimal telemetry quality when terminating Ethernet
cables.
• Use CAT5E- or CAT6-rated underwater connectors.
• Use CAT5E- or CAT6-rated patch cords that have been factory tested.
• Use CAT5E- or CAT6-rated patch panels, connectors and sockets.
• Do not untwist the cable more than 0.5 inches for CAT5E cables and not more than
0.375 inches for CAT6 cables.
• Remove as little cable jacket as possible.
M3 Sonar FLS Installation Manual