Abstract: A numerical control system executes part programs which contain parameters and arithmetic expressions containing parameters. A parameter table containing parameter values is employed to evaluate parameters and arithmetic expressions during the execution of a part program, and means is provided which enables parameter values to be changed by part program instructions or manual data entry. Macroprograms, such as canned cycles, are stored in the numerical control system in a generalized form in which their instructions contain parameters and arithmetic expressions in lieu of constants. Prior to calling such a macroprogram, the part program assigns suitable values to the parameters employed in the macroprogram.

Abstract: A numerical control system includes a main processor which performs such functions as interpolation and outputting of motion command signals to the servomechanisms on a machine tool. A separate programmable interface processor connects to the main processor bus structure and it operates as a programmable controller to control the discrete digital I/O devices associated with the machine tool. A third processor couples through a serial data link with the main processor and it operates to service peripheral I/O devices associated with the front control panel on the numerical control system.