E2-43

Internal Error (SM560-S)

ABB · AC500-S Safety Controller

What does E2-43 mean?

The SM560-S Safety PLC has encountered an unspecified internal error. This indicates a system malfunction that prevents normal operation and requires intervention.

Common Causes

  • Corrupted firmware or operating system of the SM560-S Safety PLC, leading to unexpected internal errors.
  • Hardware defect within the CPU module (e.g., memory, processor, internal bus) of the SM560-S Safety PLC.
  • Transient power supply issues (e.g., voltage sags below 21.6VDC, spikes above 26.4VDC) affecting the internal logic of the PLC.
  • Overheating of the SM560-S CPU due to inadequate panel ventilation or consistently high ambient temperatures (verify internal temperature sensor readings if accessible).
  • Critical application program error causing an unhandled exception or memory access violation within the PLC's operating system during runtime.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    1. Perform a power cycle of the SM560-S Safety PLC and observe if the internal error clears upon restart.

  2. 2

    2. Connect to the Safety PLC via engineering software and examine the diagnostic buffer for any specific sub-codes or contextual information related to the internal error.

  3. 3

    3. Re-download the boot project and the complete safety application to the SM560-S Safety PLC.

  4. 4

    4. Verify the 24VDC power supply to the Safety PLC, ensuring it is stable and within the specified voltage range (e.g., 21.6VDC to 26.4VDC) using a multimeter.

  5. 5

    5. Check the ambient temperature around the PLC panel and ensure proper ventilation; verify internal temperature sensor readings if accessible via software.

  6. 6

    6. If the error persists after all software and power checks, replace the SM560-S Safety PLC CPU module.

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Verified technical data. Last updated: March 2026

Related Faults

Source: ABB AC500-S Safety Controller