Most hardware allows a physical factory reset via DIP switches or SD cards. Note: This will wipe the program and data.

There are indeed various tools and software available that claim to offer free PLC and HMI password recovery or unlock services. These range from manufacturer-specific tools to third-party software.

October 26, 2023 Subject: Cybersecurity, Industrial Control Systems (ICS), and Operational Technology (OT) Maintenance

While the idea of an "all-in-one" free password unlock tool for PLCs and HMIs is a popular search for engineers facing lost credentials, it is a path filled with significant security and operational risks. Most "free" tools found online are not universal and often serve as a front for malicious activity. The Reality of Free "Unlock" Tools