Rockwell Automation 1756-RMxx ControlLogix Enhanced Redundancy System User Manual - Manual (Page 176)

176 Rockwell Automation Publication 1756-UM535D-EN-P - November 2012
Chapter 7 Program the Redundant Controller
We recommend that you reevaluate the watchdog times in your application if
either of these events occur:
• A second controller is added to a redundancy chassis.
• The application in a second controller that is already in the system is
modified.
Figure 54 - Watchdog Configured for Redundancy Switchover
In the event of a watchdog timeout, a major fault (type 6, code 1) results. If this
fault occurs after a switchover, the control system fails-to-safe or to the
configured hold state.
Figure 55 - Watchdog Not Configured for Redundancy Switchover