A CPU unit of a PLC executes a motion control and a sequence control. The CPU unit stores a CAM table and a control program for performing the motion control using the CAM table. When a microprocessor receives a command for altering one of a plurality of phases and/or a displacement associated with the phase, the microprocessor alters the phase and/or the displacement in the CAM table to a value that is on the basis of the command. When the microprocessor performs the alteration, the microprocessor executes a control program using a post-alteration CAM table, and outputs the execution results to an apparatus to be controlled.

A CPU unit of PLC executes a motion control and a sequence control. The CPU unit stores a control program for executing the motion control using a CAM table, and a first CAM table and a second CAM table. When a microprocessor receives a predetermined instruction during execution of the control program, the microprocessor switches the CAM table used in the execution of the control program from the first CAM table to the second CAM table. On the basis of the switching of the CAM table, the microprocessor outputs the execution results of the control program using the second CAM table to an apparatus to be controlled.

It is possible to easily change CAM tables, which are used for executing an electronic CAM operation. A CAM computation program performs an electronic CAM operation, using a CAM table that is an array in which displacements of a slave axis of an electronic CAM are associated with phases of a master axis of the electronic CAM. A CAM table generating program receives input of a CAM definition variable that defines an electronic CAM operation to be realized by a motion control, and generates a CAM table in which a CAM curve is stored as an array corresponding to the inputted CAM definition variable. A microprocessor performs a CAM computation program using the CAM table. If the microprocessor receives the input of the CAM definition variable, the microprocessor performs the CAM table generating program to generate the CAM table, and stores the generated CAM table into the main memory.