If you have an old DOP-B series HMI and have accepted the risks, here is the typical workflow for a third-party unlock tool:
To avoid needing unlock software in the future, follow these industry best practices: Delta Hmi Password Unlock Software
How do I set a password for projects on HMI? - Delta Electronics If you have an old DOP-B series HMI
There are generally three types of unlock methods: these tools rely on serial communication.
Supported devices (examples)
If the default fails and you are locked out of your own project, these methods are commonly documented by technical communities: Project File Decompilation : If you have the
Connect your PC to the HMI’s COM port (usually COM1 – RS-232). Use a 2-3-5 pin null modem cable. Do not use Ethernet; these tools rely on serial communication.