Abstract: A scheduler program includes a command to start execution of a motion calculation program in each motion control cycle, a command to cause a microprocessor to start execution of a first user program in each first user program execution control cycle, and a command to repeat output processing and input processing, start of execution of the first user program, end of execution of the first user program, and start of execution of the motion calculation program in this sequence for every period corresponding to the period of the first user program execution cycle.

Abstract: A system program includes a procedure library in which at least a procedure for controlling execution of a control program and a procedure for controlling output of output data and input of input data are included. If schedule-building data including execution order specifications for the procedures included in the procedure library is stored in a storage section, the system program causes a microprocessor to execute the procedures included in the procedure library in accordance with the procedure execution order specifications included in schedule-building data.

Abstract: A control device capable of appropriately switching operating modes when multitasking is being performed is provided. A CPU unit is provided with a task executing unit for executing a plurality of tasks in parallel, and for executing each task in cycles based on each task; and a mode switching unit for switching operating modes. The task executing unit is configured in such a manner that when in operation mode, a user program is executed for each task, and when in program mode, a user program is not executed for each task.

Abstract: A scheduler causes a microprocessor to start execution of a first control program after a communication circuit transmits output data and receives input data in a control cycle following a control circle in which execution of the first control program has ended, and causes execution of an unexecuted portion of the first control program in a control cycle following a control cycle in which execution of the first control cycle has not ended.

Abstract: The system program includes, as an execution control process of the control program, an owner-side start process that starts execution of an owner-side control program; a copy process in which, when execution of the owner-side control program ends, a global variable that is rewritten by the owner-side control program is copied from a global variable area to a synchronous buffer corresponding to the global variable; and a referrer-side start process that starts execution of a referrer-side control program.

Abstract: A microprocessor controls at least one of a first communication circuit and a second communication circuit such that a first input/output process and a second input/output process are executed in parallel. The first input/output process includes a process outputting output data from a first transfer buffer, through the first communication circuit, to a first instrument in a PLC system bus, and a process inputting input data from the first instrument, through the first communication circuit, to the first transfer buffer. The second input/output process includes a process outputting output data from a second transfer buffer, through the second communication circuit, to a second instrument in a field network, and a process inputting input data from the second instrument, through the second communication circuit, to the second transfer buffer.

Abstract: A system program includes a procedure library in which at least a procedure for controlling execution of a control program and a procedure for controlling output of output data and input of input data are included. If schedule-building data including execution order specifications for the procedures included in the procedure library is stored in a storage section, the system program causes a microprocessor to execute the procedures included in the procedure library in accordance with the procedure execution order specifications included in schedule-building data.

Abstract: A system program causes, as an execution preparation process for a control operation of a PLC, execution of a process for generating a reception buffer for storing received input data, and execution of a process for generating, for each input data referred to by a control program, an input synchronization buffer used by the control program as a reference target for the input data. The system program causes, as an execution control process for the control operation of the PLC, execution of an input copy process for copying the received input data from the reception buffer to the input synchronization buffer corresponding to the input data, and execution of a control program start process for starting execution of the control program.

Abstract: A control device capable of appropriately switching operating modes when multitasking is being performed is provided. A CPU unit is provided with a task executing unit for executing a plurality of tasks in parallel, and for executing each task in cycles based on each task; and a mode switching unit for switching operating modes. The task executing unit is configured in such a manner that when in operation mode, a user program is executed for each task, and when in program mode, a user program is not executed for each task.

Abstract: A scheduler causes a microprocessor to start execution of a first control program after a communication circuit transmits output data and receives input data in a control cycle following a control circle in which execution of the first control program has ended, and causes execution of an unexecuted portion of the first control program in a control cycle following a control cycle in which execution of the first control cycle has not ended.

Abstract: The system program includes, as an execution control process of the control program, an owner-side start process that starts execution of an owner-side control program; a copy process in which, when execution of the owner-side control program ends, a global variable that is rewritten by the owner-side control program is copied from a global variable area to a synchronous buffer corresponding to the global variable; and a referrer-side start process that starts execution of a referrer-side control program.

Abstract: A scheduler program includes a command to start execution of a motion calculation program in each motion control cycle, a command to cause a microprocessor to start execution of a first user program in each first user program execution control cycle, and a command to repeat output processing and input processing, start of execution of the first user program, end of execution of the first user program, and start of execution of the motion calculation program in this sequence for every period corresponding to the period of the first user program execution cycle.

Abstract: A microprocessor controls at least one of a first communication circuit and a second communication circuit such that a first input/output process and a second input/output process are executed in parallel. The first input/output process includes a process outputting output data from a first transfer buffer, through the first communication circuit, to a first instrument in a PLC system bus, and a process inputting input data from the first instrument, through the first communication circuit, to the first transfer buffer. The second input/output process includes a process outputting output data from a second transfer buffer, through the second communication circuit, to a second instrument in a field network, and a process inputting input data from the second instrument, through the second communication circuit, to the second transfer buffer.

Abstract: A system program causes, as an execution preparation process for a control operation of a PLC, execution of a process for generating a reception buffer for storing received input data, and execution of a process for generating, for each input data referred to by a control program, an input synchronization buffer used by the control program as a reference target for the input data. The system program causes, as an execution control process for the control operation of the PLC, execution of an input copy process for copying the received input data from the reception buffer to the input synchronization buffer corresponding to the input data, and execution of a control program start process for starting execution of the control program.