User Manual
Table Of Contents

Chapter 1 Major faults
Item Description
The second CLR instruction sets to zero the value of the fault code in the major_fault_record tag.
Clear the fault
The SSV instruction writes:
• The new values to the MajorFaultRecord attribute of this program.
• The values contained in the major_fault_record tag. Because the Type and
Code member are set to zero, the fault clears and the controller resumes
execution.
If the controller faults immediately after you switch it to the Run mode, examine
the prescan operation for the fault. Depending on the revision of your controller,
an array subscript that is beyond the range of the array (out of range) during
prescan might cause a fault.
If controller is revision Then
11.x or earlier During prescan, an array subscript that is beyond the range of the array (out of
range) produces a major fault.
12.x See the release notes for the firmware of your controller.
13.0 or later During prescan, the controller automatically clears any faults due to an array
subscript that is beyond the range of the array (out of range).
See the following procedures to clear a major fault that occurs during prescan.
• Identify when the controller is in prescan on 25
• Get the fault type and code on page 25
• Check for a specific fault on page 26
• Clear the fault on page 26
Important:
It is good programming practice to check for a specific fault before clearing that fault.
Clear a major fault during
prescan
24 Rockwell Automation Publication 1756-PM014G-EN-P – October 2014