Process for controlling a machine tool

A process by which an operator controls a machine tool, said machine tool comprising:

• a machining chamber;
• a tool arranged in the machining chamber;
• an illuminator provided in the machining chamber;
• an NC unit for performing a control of a machining operation in the chamber on the basis of an NC program, the NC unit including a manual control and a manual execution unit responsive to said manual control, and being operable alternatively in an automatic mode, and in a manual mode wherein said control is under a control of said manual execution unit, and said NC unit having a selectable one-block stop mode in which the NC program is executed for one block and then stopped;
• and
• a notification unit for issuing a notification to said operator, while said operator is continuously visually observing the interior of the machining chamber while operating the machine tool, of completion of the execution of said one block of the NC program while said control is manually executed using the manual execution unit in the one-block stop mode;
• wherein said notification unit comprises the illuminator;
• and
• wherein, in said process:
• said operator, by operating said manual control, causes the manual execution unit in said one block stop mode to execute the machining operation;
• throughout said control using the manual execution unit in said one block stop mode, said operator continuously visually observes the machining operation in said machining chamber using the manual execution unit in said one block stop mode;
• said illuminator in the machining chamber provides continuous illumination at a level of luminescence sufficient to enable said continuous visual observation by said operator of the machining operation;
• and
• said notification unit causes a change in the level of illumination emitted by said illuminator upon completion of the execution of said one block of the NC program, whereby the operator is notified of the completion of the execution of said one block of the NC program while continuously visually observing the machining operation.