To retrieve the password without deleting the program, you must read the hex data directly from the MMC.
After successfully unlocking the S7-300 PLC password:
If the password is lost and the default does not work, you must perform a Memory Reset (MRES)
: Inserting an MMC from a protected unit into a CPU with a different hardware configuration often triggers an "MMC Error" or "Config Mismatch".
Some very old, pre-2009 versions of the S7-300 may respond to the default password Basisk . 3. Ethical and Technical Protection Levels supports three main protection levels: Level 1: Full access (Default).