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Rockwell Automation 1756-RMxx ControlLogix Enhanced Redundancy System User Manual User Manual

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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