If you do not have a backup and only need to reuse the hardware, you can perform a factory reset to clear the password protection. Switch Reset (MRES) Switch off the supply voltage. Remove the MMC card. Hold the mode selector switch to and power the CPU back on.
Specialized scripts scan the hex data for specific offsets where the S7-300 stores its 8-character block or level passwords. siemens s7 300 password unlock exclusive
Unlocking a Siemens S7-300 PLC Go to product viewer dialog for this item. If you do not have a backup and