Rockwell Automation 1756-CN2_CN2R, Series B ControlLogix ControlNet Interface Module - Manual (Page 6)

6 ControlLogix ControlNet Interface Module
Publication 1756-IN607A-EN-P - February 2008
The ControlNet Interface Module and Redundant Media
Use the 1756-CN2 ControlLogix ControlNet series B module if
redundant media is not necessary. Applications requiring redundant
media must use the 1756-CN2R module.
Understanding Standalone and Redundant Control
You can use the 1756-CN2R series B modules for standalone or
redundant control. For standalone control, only one set of modules is
required. For redundant control, two ControlLogix chassis are
populated with identical pairs of modules called partners. The chassis
that performs active control is called the primary chassis and the
modules in the chassis are called primary modules. The other chassis
is called the secondary chassis and the modules in the chassis are
called secondary modules.
These installation instructions discuss both standalone and redundant
control; read them carefully to distinguish the procedures and
requirements for each type of control.
If you use redundant control, you must select the same ControlNet
network address for each set of partner modules (primary and
secondary). You must also place the partner modules in the same
corresponding slots in their respective redundant-control chassis
pair.
For more redundancy information, refer to the ControlLogix
Redundancy System User Manual, publication 1756-UM523F.
IMPORTANT