Numerical controller

A numerical controller having a function of selectively displaying one of different frames, each including at least one icon display area, on a display screen, said numerical controller comprising:

• storage means for storing icon definition data for defining different icons, and icon designation data for designating ones of the different icons to be respectively displayed in the icon display areas of the different frames, said different icons including a child icon to be acquired by subjecting a parent icon that is another of the different icons to one of conversions of changing display configuration, changing a display size and changing a display color, and said icon definition data for the child icon including designation of a parent icon of the child icon and contents of the one of the conversions to which the parent icon is to be subjected;
• determining means for determining one of the different icons to be displayed in each icon display area of selected one of the different frames according to the icon designation data stored in said storage means, and reading icon definition data of each of the determined icons from said storage means;
• and
• displaying means for displaying each of the icons determined to be displayed in the corresponding icon display area of the selected frame based on the icon definition data determined by said determining/reading means, wherein said displaying means displays the child icon by subjecting the parent icon of the child icon to the one of the conversions according to the designations in the icon definition data for the child icon.