NUMERICAL CONTROL UNIT WITH SCHEDULE SKIP CAPABILITY

A numerical control (NC) machine tool is controlled by a machining program, which gives the machine tool instructions with respect to the machining of a locus on a workpiece, machining conditions and the like, and responds to a variety of input data which may be stored or registered in a manner that comprises a schedule run, and includes a schedule skip capability. The schedule skipping capability permits portions of the scheduled run to be skipped at the occurrence of an event, such as an alarm, but allows machining to be continued without stopping the schedule run. The scheduled run may skip to a new program, to commands for changing tools, pallets, workpieces and the like, or to conduct a measurement schedule run in association with the machining run. The memory for storing a measurement schedule corresponding to a machining schedule allows any measurement schedule to be utilized without impairing machining productivity greatly. The memory is capable of registering two or more schedule elements as one group, thereby allowing a complicated schedule, such as the repeated machining of multiple sets of workpiece machining, to be made out easily with a small-capacity memory. A clock and the memory for storing run start time corresponding to a schedule allow run start time of day and run interval time to be set for unattended operation. Schedule data may be displayed for schedule specification and editing.