`1. Symptom Analysis: The ControlLogix 5580 is experiencing a Type 04 Code 01 fault, indicating a fatal error within a Timer or Counter instruction where the Preset (PRE) or Accumulated (ACC) values are corrupted or out of bounds. Safety First: LOTO (Lock-out/Tag-out) is mandatory on the main conveyor line drive before proceeding. Ensure the equipment cannot unexpectedly start when the logic fault is cleared. Resolution: Connect your engineering workstation to the CPU via Ethernet/USB and open Studio 5000. Go online with the controller and navigate to the Controller Faults dialog to verify the exact rung causing the Type 04 Code 01 error. Inspect the identified Timer/Counter instruction. Verify the .PRE value is within the valid DINT range and the .ACC value is not negative. Correct the out-of-range parameters (e.g., reset .ACC to 0). Clear the major fault from the Controller Properties tab. Switch the controller back to Remote Run mode and verify the conveyor logic executes normally.`