Failed to Set 'Reboot at Powerfail' Parameter

What does E2-27 mean?

The CPU failed to set the 'Reboot at powerfail' parameter, which controls the system's behavior during power interruptions. This means the system might not restart correctly or automatically after a power failure, potentially requiring manual intervention to resume operation. This impacts system resilience.

• Parameter write protection enabled (e.g., via a DIP switch or software lock) on the CPU.
• Corrupted configuration area in the CPU's non-volatile memory preventing parameter storage.
• Firmware bug or insufficient permissions preventing the system from modifying core boot parameters.
• Power supply brownout during the attempt to write the parameter to persistent memory.
• Incorrect parameter index or value attempted for the 'Reboot at powerfail' setting (e.g., P0-05).

Click steps to track your progress.

1. 1

   1. Verify the physical write protection switch (e.g., SW1) on the CPU is in the 'Run' or 'Write Enabled' position.

2. 2

   2. Attempt to set the 'Reboot at powerfail' parameter (e.g., P0-05) via the engineering software.

3. 3

   3. Perform a controlled power cycle of the CPU by removing and reapplying 24VDC power.

4. 4

   4. Check the 24VDC power supply for stability and sufficient current capacity.

5. 5

   5. Re-flash the CPU firmware to ensure the operating system is not corrupted.