Allen-Bradley 1756-L61 User Manual page 176

Chapter 12 Redundant Systems
Redundant Chassis
176
Figure 46 - ControlLogix Enhanced Redundancy System
Workstation
Primary
I/O Connected via ControlNet Network
I/O can be connected via an EtherNet/IP network beginning with Enhanced Redundancy System revision 19.50.
Redundancy requires no additional programming and is transparent to any
devices connected over an EtherNet/IP or ControlNet network.
Redundancy modules that are placed in each redundant chassis maintain the
communication between the redundant chassis.
Depending on how you organize your project, outputs can experience a change in
state (bump) during a switchover:
• During the switchover, outputs that are controlled by the highest priority
task experience a bumpless switchover. For example, outputs do not revert
to a previous state.
• Outputs in lower priority tasks can experience a change of state.
For detailed information about ControlLogix redundancy systems, see the
ControlLogix Enhanced Redundancy User Manual, publication 1756-UM535.
Rockwell Automation Publication 1756-UM001O-EN-P - October 2014
HMI
Ethernet
Switch
Secondary