The lock state methods are members of the VI class that can be called with an invoke node. Simply drop down an invoke node and wire a a reference to a VI to it. The lock state methods can be used to programmatically lock and unlock VIs. There are two of them and I've included their names and descriptions below:
Get Lock State: Returns the lock state of the VI and indicates whether the password for the VI is in the password cache.
Set Lock State: Sets the lock state of a VI. If "interactive" is FALSE (default), you can use password to either unlock a password-protected VI or set the password of an unprotected VI. If "interactive" is TRUE, LabVIEW ignores password and displays a dialog box that prompts you to change the lock state.
Regards,
E. Sulzer
Applications Engineer
National Instruments