Numerical controller which can be parametrised by the machine manufacturer

A method for operating a numerical controller, comprising:

• executing with the numerical controller a system program;
• while executing the system program, executing with the numerical controller a part program which actuates position-controlled axes of a machine tool that is controlled by the numerical controller;
• retrieving with the numerical controller sequentially command sets of the part program, with the command sets comprising functions that are available especially for the numerical controller;
• executing the retrieved functions with the numerical controller only when the retrieved functions comply with permitted boundary conditions, while otherwise not executing the retrieved functions;
• receiving with the numerical controller, prior to executing the part program while executing the system program, information that determines the permitted boundary conditions via an interface that is protected from unauthorized access;
• and
• determining based on at least one of the permitted boundary conditions which combinations of the retrieved functions are released or blocked.