Rockwell Automation 1786-series ControlNet Fiber Media Planning and Installation Guide - Manual (Page 15)

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 15
Get Started with the ControlNet Network Fiber Media System Chapter 1
Determine Network
Topology We suggest that you take sufficient time to plan the installation of your network
before assembling any components. The table defines some of the basic
ControlNet network terminology used in example topologies.
The illustration describes an example trunk line topology.
Item Term Description Item Term Description
Passive tap
with drop
cable The connection between any device and the
cable system. The length of the drop cable is
1 m (3.28 ft). Coax
repeater An active physical layer component that
reconstructs and retransmits all traffic it hears
on one coax segment to another coax segment.
Node or
device Any physical device connecting to the
ControlNet network cable system that
requires a network address to function on the
network. Fiber
repeater An active physical layer component that
reconstructs and retransmits all traffic it hears
on one fiber segment to another fiber segment.
A coax port on the repeater adapter is
available to relay the fiber traffic to the coax
segment.
Terminator
(dummy
load) Terminates a tap drop cable that has yet to
be connected to a node to help prevent noise
on the line. Terminating
resistor A 75
Ω
resistor mounted in a BNC plug to
absorb electrical energy of the signal at the
end of the cable to prevent reflections. Each
end of a segment must be terminated.
T CR
N FR
D TR
41326
Network
Coax Segment Coax Segment
Coax Segment
T T T T T T T T T
T T T T T
N N N N N N
N N D N
FR FR
CR
CR
TR TR TR
TR TR
TR
Trunk Line
Drop Line
Fiber segment to isolate or
extend a segment
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