Description:
You can choose between three protection levels:

• Protection level 1: corresponds to the default behavior
• Protection level 2: read-only access possible
• Protection level 3: neither read nor write-access possible

You can assign a CPU password within the hardware configuration of your S7 station. Open the Properties dialog box of the CPU there. The protection level 2 (read-only access) and a password assignment are recommended inside the Properties dialog box.

A user who does not know the password can then read the program in the CPU, without entering a password. However, he cannot make changes within the program.

Fig. 1: Setting CPU protection

Block protection (Know_How_Protect) can be assigned for self-created STEP 7 blocks. You can find more information about this under "Block protection (Know_How_Protect) for DBs, FBs and FCs" - entry ID: 10025431.

If you forget your password:
If you forget the password, you do not have write-access (or read-access in level 3) in the password-protected CPU.
To restore access, you have to reset the CPU and reload the program into the CPU.

Note:
The password only becomes active once the changed data has been downloaded into the S7-CPU.

Keywords:
Block protection