If possible, have a backup of your PLC's program and configuration. This can prevent data loss during the recovery process.

: Siemens has a global support network. Reaching out to their support team might provide you with the official and secure methods to reset or retrieve passwords.

: You can perform a hardware reset by cycling the mode selector switch. Switch off the power and remove the MMC.

Before attempting any unlock, you must know what you’re up against. Siemens S7-300 CPUs (e.g., 313C, 314, 315-2 DP) have three main protection levels in SIMATIC Manager (Step 7):

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