Power on the PLC. The controller will copy the "empty" state, effectively wiping the internal memory and password.
What if you need to reset the password but keep the I/O configuration and hardware setup? There is a little-known method using a blank SIMATIC Memory Card. siemens s7-1500 password reset
: Since the S7-1500 stores its configuration and passwords on the SIMATIC memory card , you can clear the password by: Removing the SMC from the PLC. Inserting it into a Siemens Field PG Power on the PLC