Rockwell Automation 1786-series ControlNet Coax Media Planning and Installation Guide - Manual (Page 17)

17 Publication CNET-IN002B-EN-P - June 2010 17
Chapter
2
Plan a ControlNet Coax Media System
Introduction The information in this chapter will help you determine your network
requirements. Along with this data, consult engineering drawings of your
facility for specific information concerning the best location for installing
your network.
For example, dusty indoor or harsh outdoor conditions will determine whether
you need IP20 or IP67 components. IP means Ingress Protection, a rating
based on IEC 60529 standard to determine the strength of an enclosure for
electrical equipment. Rugged IP67 equipment is typically priced higher, so you
must plan accordingly to stay within budget.
See page 34 for more information.
The table outlines what you should consider when designing your system.
IMPORTANT
The ControlNet cable system is a ground-isolated coaxial
network. Proper selection of cable, connectors, accessories,
and installation techniques is necessary to make sure it is not
accidentally grounded.
Topic Page
Determine the Number of Taps You Need 18
Choose the Connection for Programming Devices 20
Choose the Cable Type 22
Determine Trunk Cable Section Lengths 22
Decide the Number of Terminating Resistors 25
Determine Repeater Requirements 25
Determine Propagation Delay 30
Choose Connectors 31
Decide Whether to Use Redundant Media 31
Decide Whether You Need IP67 Media 34
Follow Application and Installation Guidelines 35
Plan the Tap Connections 38
Review the Plan, Order Components 40