Disclosed is a substrate processing apparatus including one or more operation elements, the substrate processing apparatus includes a processing unit controlling operation of the substrate processing apparatus, and a controller controlling independently the one or more operation elements of the substrate processing apparatus, monitoring operation of the processing unit, and maintaining operation states of the one or more operation elements when the operation of the processing unit is restarted or terminated.

Simulation methods for simulating a real control (2) for an industrial process, a plant or a machine shall be able to determine errors occurring in the course of simulation more easily. For this purpose the invention proposes that the simulation system (7) stores intermediate states during the simulation and time-stamps them, wherein a stored intermediate state can be reloaded into the simulation system (7) at a later time and a simulation carried out on the basis thereof. As a result, simulations do not always need to start with the beginning of the control program to be simulated.

A numerical control apparatus includes a program storage, a display device, an automatic-operation control unit, a suspending operation unit, a program manipulation unit, and an automatic-operation monitoring unit. The automatic-operation monitoring unit monitors an execution state of the automatic-operation control unit. At a time of resumption of execution of an NC program after suspension of the execution of the NC program by the suspending operation unit, the automatic-operation monitoring unit checks whether a resumption block containing a character designated in the program manipulation unit immediately before the resumption is a preset resumable block or not. When the resumption block is the resumable block, processing in the automatic-operation control unit is resumed from the resumption block, while when the resumption block is not the resumable block, the processing is halted.

A numerical controller restores internal data of an NC section, shifts to a machining resumption temporary suspension state, and passes an identification number extracted from NC section program resumption block data to a PMC section. The PMC section, when receiving the identification number, restores a signal state of the PMC section and a state of a peripheral machine section, and, when the restoration is completed, notifies the NC section of the completion of the restoration. Then, the NC section cancels the machining resumption temporary suspension state and shifts to a state in which machining can be resumed.