A program correction device is configured to generate a plurality of machining paths obtained by smoothing each of cutting paths; select a reference path serving as a reference from among the plurality of machining paths; set a plane reference point on the reference path; calculate an intersection point between the plurality of machining paths and a plane passing through the plane reference point and being perpendicular to the reference path at the plane reference point, perform a smoothing processing based on the calculated intersection point and the plane reference point, and calculate a point on an obtained curved line as a correction command point of the plurality of machining paths; and generate a post-correction machining program obtained by inserting the correction command point in the machining program.

Provided is cam curve generating device that generates a cam curve that is smoothly connected to an out-section cam curve and reduces fluctuations in speed of a driven shaft and acceleration of the driven shaft. Cam curve generating device includes section divider that divides an application section into a plurality of sub-sections, and cam curve generator that generates a cam curve in the application section. The division condition includes a length and the type of each of the plurality of sub-sections. The boundary condition includes a position, speed, and acceleration of the driven shaft at each of a start and an end of the application section. Cam curve generator generates a cam curve that allows a position of the driven shaft, speed of the driven shaft, and acceleration of the driven shaft to be continuous at each of boundaries of the plurality of sub-sections.

A program correction device is configured to generate a plurality of machining paths obtained by smoothing each of cutting paths; select a reference path serving as a reference from among the plurality of machining paths; set a plane reference point on the reference path; calculate an intersection point between the plurality of machining paths and a plane passing through the plane reference point and being perpendicular to the reference path at the plane reference point, perform a smoothing processing based on the calculated intersection point and the plane reference point, and calculate a point on an obtained curved line as a correction command point of the plurality of machining paths; and generate a post-correction machining program obtained by inserting the correction command point in the machining program.

A method for operating a digital control device, and a digital control device, for controlling a manufacturing machine for manufacturing a workpiece, are disclosed. In the method, workpiece data are provided on the digital control device, and CAM software is provided on the digital control device. Program instructions for manufacturing the workpiece are generated by the manufacturing machine by the CAM software in accordance with the workpiece data. The program instructions are executed by the digital control device for controlling the manufacturing machine for manufacturing the workpiece. In order to protect the control program for the digital control device against unauthorized access, the generated program instructions are saved in encrypted form in a non-volatile memory of the digital control device and are only decrypted again immediately before the execution in a volatile memory of the NC core of the digital control device.