If the PLC has a password for HMI communication, it is usually managed in the Protection tab of the CPU properties within the hardware configuration.
: This wipes the internal RAM, but the password on the MMC will remain until the card is formatted. 📄 Technical Documentation unlock s7300 plc password
: If you have the original project file but forgot the password, it is often stored in the project database, not just the hardware. ⚠️ Factory Reset (Data Loss) If the PLC has a password for HMI
The S7-300 series utilizes a protection hierarchy managed via the CPU's properties in Step 7 (TIA Portal or Classic). The protection is generally divided into three levels: ⚠️ Factory Reset (Data Loss) The S7-300 series
The STOP LED should flash quickly, indicating the memory is being cleared. Once it stays lit, the reset is complete. Siemens SiePortal 3. Reset via STEP 7 / TIA Portal