Rockwell Automation 1756-RMxx ControlLogix Enhanced Redundancy System User Manual - Manual (Page 18)

18 Rockwell Automation Publication 1756-UM535D-EN-P - November 2012
Chapter 1 About Enhanced Redundancy Systems
I/O Modules in Enhanced Redundancy Systems
In an enhanced redundancy system, you can use only I/O modules in a
remote chassis. You cannot use I/O modules in the redundant chassis pair.
This table describes differences in network use for I/O in enhanced redundancy
systems.
For more information on using remote and 1715 redundant I/O over an
EtherNet network, see I/O Placement on page 44 and the Redundant I/O
System User Manual, publication 1715-UM001 .
Remote I/O Module Placement Available with Enhanced System, Revision 19.052, 19.053,
or 20.054
Available with Enhanced System, Revision 16.081 or
Earlier
EtherNet/IP I/O network 
1715 Redundant I/O System 
ControlNet network  
DeviceNet network (1)  
Data Highway Plus (1)  
Universal Remote I/O (1)  
(1) In an enhanced redundancy system, you can access remote I/O modules on this network only via a ControlNet or EtherNet/IP network bridge.