Some free tools are simple dictionary or brute-force scripts. Against a modern Siemens or Allen‑Bradley PLC with a 5-attempt lockout, these are useless. They may also crash the PLC, forcing a costly factory reset.
Companies like (China), Radwell International (USA/UK), or Industrial Automation Exchange offer password removal for $150–$500. They physically image the device and return it unlocked with a copy of the program. Cheaper than replacing the HMI. plc hmi password unlock software free download
but requires electronics skill, a soldering iron, and hours of hex-dump analysis. For a single machine, it is rarely worth the risk of destroying the HMI. Some free tools are simple dictionary or brute-force scripts
Some sites and social media posts frequently advertise these tools, but they are generally not verified and may be PLC Journal but requires electronics skill, a soldering iron, and
Most "one-click" free downloads found on unofficial forums carry high risks. Industrial software is specialized, and generic cracking tools often contain malware that can infect your engineering workstation. Many free "crack" files are Trojans.
If you own the machine, you have a right to access it, but you must prove ownership.
If the machine is older than 5 years, a new HMI from Maple Systems, Weintek, or C-More costs $300–$800 and includes free programming software. Recreate the screens (often 4-8 hours of work). No password issues in the future.