Rockwell Automation 1756-RMxx ControlLogix Enhanced Redundancy System User Manual - Manual (Page 148)

148 Rockwell Automation Publication 1756-UM535D-EN-P - November 2012
Chapter 7 Program the Redundant Controller
The diagram below shows a lower priority task that has not been completed and a
switchover occurs. The lower priority task and programs are executed from the
beginning of the program where the switchover occurred. This is because the
program uses the default configuration and crossloads and synchronization
points occur at the end of each program.
Figure 36 - Periodic Task Execution After Switchover When Configured to Crossload After
Programs
The diagram below shows a lower priority task that has not been completed and a
switchover occurs. The lower priority task and programs are executed from the
beginning and not at the program where the switchover occurred. This is because
the crossloads and synchronization points were not configured to occur at the
end of each program.
Figure 37 - Periodic Task Execution After Switchover When Configured Not to Crossload After
Programs
For more information about programs and tasks with controllers, see the
Logix5000 Controllers Tasks, Programs, and Routines Programming Manual,
publication 1756-PM005 .
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