Critically, Fatek does not store passwords in a separate EEPROM chip that can be easily bypassed via hardware hacking (like some older Siemens S5 or Mitsubishi units). Instead, the password is embedded within the main program memory block. When you attempt an upload, the PLC's firmware runs a checksum routine asking: "Does the input hash match the stored hash?"
Fatek PLCs, particularly the and B1/B1z series, use WinProladder software for programming and security configuration. fatek plc password unlock software