A method of operating a terminal unit which is connectable via a communication interface to a control apparatus for controlling a laser beam processing operation, said method comprising:
- establishing communication, in an initialization mode, between the terminal unit and the control apparatus by means of the communication interface;
- downloading an application program, stored in the control apparatus, to the terminal unit;
- storing said downloaded application program in the terminal unit for execution of the application program by the terminal unit;
- inputting, at the terminal unit, selected values of laser beam processing conditions to the control apparatus according to the application program stored in the terminal unit;
- and
- displaying, at the terminal unit, the selected values which were input at the terminal unit.