Basic cable terminology – Rockwell Automation 1786-series ControlNet Coax Media Planning and Installation Guide User Manual
Page 10
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Publication CNET-IN002B-EN-P - June 2010
Chapter 1 ControlNet Cable System Overview
Basic Cable Terminology
The table defines some of the basic ControlNet network terminology.
The illustrations throughout this section show how each of the components
identified in the above table forms an efficient, deterministic, and repeatable
communication network.
ControlNet Coax Media Cable System
Item
Term
Description
Item
Term
Description
Trunk line
The trunk cable is the bus or central part
of a cable system, with a trunk-cable
section being a length of cable between
any two taps. Each node is connected to
the trunk cable with a tap.
Repeater
A two-port component that connects
segments together and boosts the signal
passing from one segment to the other.
Bridge
A device that provides a communication
connection between networks.
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.
Node or
device
Any physical device connecting to the
ControlNet cable system that requires a
network address to function on the
network.
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).
R
B
TR
N
T
Link
TR
TR
TR
TR
TR
TR
R
T
T
T
T
T
T
T
T
T
T
T
T
B
Network
N
N
N
N
N
N
N
N
Link (1 segment)
Trunk Line
Drop Line
44984
Trunk Cable with
BNC/TNC Connectors