Rockwell Automation 1756-L6x_L7x ControlLogix System User Manual - Manual (Page 185)

Rockwell Automation Publication 1756-UM001O-EN-P - October 2014 185
Troubleshoot the Module Appendix A
Fault Type Determination
To display recent fault information in the Major Faults tab of the Module
Properties screen, you must check the Major Fault on Controller option in the
Connection tab.
When you are monitoring the configuration properties of a module in the Logix
Designer application and receive a Communication fault message, the Major
Faults tab indicates the type of fault under Recent Faults.