Rockwell Automation 1756-RMxx ControlLogix Enhanced Redundancy System User Manual - Manual (Page 133)

Rockwell Automation Publication 1756-UM535D-EN-P - November 2012 133
Configure the Redundancy Modules Chapter 6
Initiate Locked Switchover
The Initiate Locked Switchover command is available only when the chassis
redundancy state is Primary with Locked Secondary. That is, the Initiate Locked
Switchover is available only after the lock for update is complete.
Clicking Initiate Locked Switchover results in your secondary chassis assuming
control and becoming the new primary. The old primary is now the new
secondary chassis and you can update the firmware of the modules in the new
secondary chassis.
Figure 32 - Illustration of Switchover
The difference between a locked switchover and a normal switchover is that the
locked switchover can be initiated only by the user. The normal switchover can be
initiated by a user or by a fault in the primary chassis.
CH2 CH1 OK CH2 CH1 OK
CH2 CH1 OK CH2 CH1 OK
Chassis A
Chassis A
Chassis B
Chassis B
Pri
mar
y
Pri
mar
y
Se
co
nd
ar
y
Se
co
nd
ar
y