ControlLogix Major Fault Type 7 Code 41 (Load Type Mismatch)

Q: What causes Rockwell Automation / Allen-Bradley ControlLogix / CompactLogix (Logix 5000) fault T07:C41?

1. Controller replaced with a different catalog number: Compare the installed controller catalog number with the controller type in the project. 2. Memory card from another machine: Confirm which project is on the card before loading or overwriting it.

Loading from nonvolatile memory failed because of a controller type mismatch: the project on the card was saved for a different controller type. Rockwell’s corrective action: change to a controller of the correct type, or download the project and store it on the memory card.

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When it happens

At power-up or on a load from the memory card
After a controller or memory card was replaced

Likely causes and checks

1Controller replaced with a different catalog number

Points to it: Fault after a hardware swap; the card came from the old controller.
Check: Compare the installed controller catalog number with the controller type in the project.

2Memory card from another machine

Points to it: Card was moved or reused from a different system.
Check: Confirm which project is on the card before loading or overwriting it.

Telling it apart

C41 is the controller type; C42 is the firmware revision; C43 is a corrupt image (bad checksum).

Evidence to collect

Major Faults tab screenshot
Controller catalog number and the controller type in the project
Origin of the memory card

Work on fuel trains, burners, pressure vessels and electrical equipment must be done by qualified personnel following the manufacturer’s documentation and local codes. Never bypass a safety device or interlock.

Rockwell Automation / Allen-Bradley ControlLogix / CompactLogix (Logix 5000) fault T07:C41: Nonvolatile fault: load failed, controller type mismatch