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

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282

Rockwell Automation Publication 1756-UM535D-EN-P - November 2012

Appendix F

Enhanced Redundancy System Checklists

Scan time is minimized by using these techniques when possible:
Unused tags are eliminated.

Arrays and user-defined data types are used instead of individual tags.

Redundancy data is synchronized at strategic points by using the Synchronize Data after Execution setting in the Program Properties dialog box.

Programming is written as compactly and efficiently as possible.

Programs are executed only when necessary.

Data is grouped according to frequency of use.

DINT tags are used instead of SINT or INT tags.
For produced/consumed data, the communication module in the remote chassis that holds the consuming controller uses the Comm Format: None.

Critical messages from a remote chassis to redundant chassis use cached connections.

Active tags on scan per controller are less than 10,000 tags/second.

(1) Note that the project loaded on the primary controller is automatically crossloaded to the secondary controller when sychronization occurs.

Requirement