To highly accurately predict remaining machining time required for cutting, a controller of a machining time prediction device includes a storage in which a machining program is stored, a simulator that performs a simulation in which a cutting machine cuts a workpiece in accordance with the machining program to generate a control pattern in which control information of a spindle and a holder is recorded, a machining time calculator that generates, based on the control pattern, a machining time table in which remaining machining time for each step of the machining program, a machining time acquirer that acquires a step of the machining program cutting of which is performed by the cutting machine at a current time point and acquires the remaining machining time for the step of the machining program, which has been acquired, from the machining time table, and a display controller that displays the remaining machining time that has been acquired by the machining time acquirer on a display screen.

It is an object to provide a plant monitoring controller that is used as a plant monitoring controller and that can confirm the soundness of a clock signal serving as a reference for operation of each function unit and can diagnose the soundness of a clock signal inspection device itself, thereby having high reliability based on an accurate clock signal. By using two clock signals having the same frequency, soundness of the respective clocks is diagnosed in two clock signal inspection circuits, and during normal operation of one system, a clock error is caused to occur in the other system in a pseudo manner and detection operation of the clock signal inspection circuit is confirmed, whereby online diagnosis of the clock signal inspection device itself is enabled.

An NC machine tool is provided with a display device capable of displaying processing time individually for each function command of a block of an NC program. The display device of the NC machine tool is capable of displaying processing time for each function command. Thus, an operator is able to identify processing time for each function command via the display device.

To highly accurately predict remaining machining time required for cutting, a controller of a machining time prediction device includes a storage in which a machining program is stored, a simulator that performs a simulation in which a cutting machine cuts a workpiece in accordance with the machining program to generate a control pattern in which control information of a spindle and a holder is recorded, a machining time calculator that generates, based on the control pattern, a machining time table in which remaining machining time for each step of the machining program, a machining time acquirer that acquires a step of the machining program cutting of which is performed by the cutting machine at a current time point and acquires the remaining machining time for the step of the machining program, which has been acquired, from the machining time table, and a display controller that displays the remaining machining time that has been acquired by the machining time acquirer on a display screen.

It is an object to provide a plant monitoring controller that is used as a plant monitoring controller and that can confirm the soundness of a clock signal serving as a reference for operation of each function unit and can diagnose the soundness of a clock signal inspection device itself, thereby having high reliability based on an accurate clock signal.

By using two clock signals having the same frequency, soundness of the respective clocks is diagnosed in two clock signal inspection circuits, and during normal operation of one system, a clock error is caused to occur in the other system in a pseudo manner and detection operation of the clock signal inspection circuit is confirmed, whereby online diagnosis of the clock signal inspection device itself is enabled.

An NC machine tool is provided with a display device capable of displaying processing time individually for each function command of a block of an NC program. The display device of the NC machine tool is capable of displaying processing time for each function command. Thus, an operator is able to identify processing time for each function command via the display device.