28 Rockwell Automation Publication 1756-UM535D-EN-P - November 2012
Chapter 2 Design an Enhanced Redundancy System
Redundant Chassis
You can use any ControlLogix or ControlLogix-XT chassis in a redundant chassis
pair as long as the two chassis used are the same size. For example, if the primary
chassis in your redundant chassis pair uses a 1756-A4 chassis, the secondary
chassis must use a 1756-A4 chassis.
You can use the 1756-A4LXT chassis with the enhanced redundancy system,
revision 19.052 or later. For a list of the ControlLogix chassis available for use in
an enhanced redundancy system, see Table 4 on pa g e 24
.
Redundant Chassis Configuration Requirements
These configuration parameters must match for the components in a redundant
chassis pair during normal system operation:
• Module type
• Chassis size
• Slot placement
• Firmware revision
• Series level. See page 32.
Figure 3 - Example of Redundant Chassis Pair
When using 1756-L7x controllers in your system, you must use revision 19.053
or later.
CH2 CH1 OK
CH2 CH1 OK