Abstract: In a master unit, clock signals from a clock are counted by a counter, and clock data is generated. This clock data is outputted to a slave unit by a driver, and stored in clock data storage memory. The slave unit stores clock data received by a receiver in the clock data storage memory. A processor for a program controller of the master and slave units starts up, and executes the synchronized operation of an operating program of axes that are synchronized on the basis of clock data stored in the clock data storage memory. It is also possible to commence operation of an axis under other conditions without relying on clock data. If override is applied to clock data, override will apply only to an axis that is synchronized and operated in accordance with clock data.

Abstract: A synchronized operation system by which a plurality of independently controlled numerical control apparatuses (CNCs) are made to carry out a synchronized operation. An external signal generation circuit (1) supplies an external timing signal to respective CNCs (2,3), from the outside, and internal signal generation circuits (10, 20) generate internal timing signals for independently operating the CNCs (2, 3). Selection circuits (9, 19) select one of the external timing signals and the internal timing signal, and when the external timing signal is selected, the respective CNCs (2, 3) are operated by using the selected external timing signals as basic timing signals. Therefore, no time lag occurs between the basic timing signals of the respective CNCs (2, 3) an and thus the respective CNCs (2, 3) can carry out an extremely a closely synchronized operation, such as an interpolation, based on the basic timing signals.