: The most direct way to remove a password is to clear the PLC memory entirely. This deletes the user program, data blocks, and the password, resetting the CPU to factory defaults.
This is where the confusion lay. Many users assumed the S7-300 MMC functioned like a USB stick or an S7-200 cartridge. It did not. simatic s7 200 s7 300 mmc password unlock 2006 09 11
For many older S7-300 versions manufactured before 2009, the default factory password is often Hardware Factory Reset (MRES) : The most direct way to remove a
| Level | Restriction | |-------|-------------| | 1 | Full access | | 2 | No write to EEPROM/MMC | | 3 | No upload/modify without password | | 4 | No access without password | and the password