Unlocking Legacies: SIMATIC S7-200 and S7-300 MMC Password Recovery and Resets
If the original password is "MASTER01":
This technique is the most common and effective way to recover a program from a password-protected S7-300 PLC without the Siemens hardware programmer. It bypasses the CPU entirely and works directly with the MMC card's data. simatic s7 200 s7 300 mmc password unlock 2006 09 11