When you set a password for Level 3 access control, you cannot change settings from the loader or clear the memory unless you enter the password for authentication.
(You cannot initialize the resource, either.)
For SPH300 user ROM card adapted CPUs (with the suffix R) or SPB/SPE, you can clear the program including the password using an optional user ROM card by the following steps.
*1  For SPH300, if 'User ROM run' is set to OFF in the CPU running definition of the PLC, projects in a user ROM card cannot

     be uploaded and the password cannot be cleared.
*2  User ROM cards cannot be used with SPH300 CPUs that do not support user ROM cards (types with no suffix R) and

     board controllers. Therefore, the password cannot be cleared. The type of an optional user ROM card is NP8PCF-256 for

     SPH300, and NW8PMF-8 for SPB/SPE.

 

[Password clear procedure for SPH300]
1) Format (initialize) the user ROM card
     by the memory card utility function of the loader.
2) Set the mode selection switch of the CPU to 'UROM-TERM' position, insert the user ROM card in the CPU, and then, turn

     on the power.

These steps clear all the memory contents including the password in the SPH300 CPU.

 

[Password clear procedure for SPB/SPE]
1) Prepare an SPB/SPE unit in which no password is set.
    Set the SPB/SPE unit to 'SX mode' using 'System software utility.'
2) Set the write-protect switch of the user ROM card to 'WRITE ENABLE', and then insert it in SPB/SPE.
3) Load a program (an empty program is OK.) to SPB/SPE.
4) Set the write-protect switch of the user ROM card to 'WRITE PROTECT.'
5) Insert the user ROM in the SPB/SPE in which a password is set, and then turn on the power.
These steps rewrites the memory contents of the SPB/SPE into the contents of the user ROM, clearing the password.