Chapter 19 Password Management and Data Protection Generally speaking, developers pack core techniques or low-level programs in function blocks. If object code is gotten in the way described above, all the techniques may be analyzed. To prevent this situation, the users can set a subroutine password before the project is downloaded. If the users set a subroutine password, the subroutine password will become the POU passwords which protect the POUs of the function block type function block type, the system will ask the users to type the correct passwords. transformed from the object code which is uploaded.
As a result, if the users want to open the POUs of the 19.5.2 Setting and Unlocking a Subroutine Password After users click the Tools menu, point to Program Settings , and click Subroutine Password Setting , the Subroutine Password Setting window will appear. The message at the bottom of the window indicates whether the subroutine is protected by a subroutine password. If the subroutine is not protected by a subroutine password, there will be two boxes used to set a subroutine password in the Subroutine Password Setting window. If the users want to set a subroutine password, they have to type the same password in the two boxes, and click OK .
If the subroutine is protected by a subroutine password, there will be one box used to unlock the subroutine password in the Subroutine Password Setting window. If the users want to unlock the subroutine password, they can type the correct password in the box, and click OK . The users can only type English letters, numerical digits, and spaces in the window. A subroutine password is case-sensitive. After the users set a subroutine password, the subroutine will be protected by the subroutine password. The window will be closed after the users click Cancel . 19-11