Cpu of plc, system program for plc, and recording medium storing system program for plc
AssigneeOMRON Corporation
InventorsYoshihide NISHIYAMA, Shigeyuki EGUCHI, Osamu HAMASAKI, Tatsuya KOJIMA
Life of this patent
Estimating the term…
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.
Claims30
A CPU unit of a PLC controlling a control target, comprising:
- a microprocessor;
- a memory;
- and
- a communication circuit, wherein
- the CPU unit of the PLC is configured to control the control target by repeating transmission of output data, reception of input data, and execution of a control program that uses the input data to generate the output data,
- the memory store the control program, a system program that controls the execution of the control program, and attribute data of a variable that is used by the control program,
- the microprocessor executes the system program and the control program that are stored in the memory,
- the communication circuit transmits the output data and receives the input data,
- the attribute data include, when the variable is a global variable that is referenced by a plurality of the control programs, information specifying one owner-side control program that rewrites the variable and information specifying at least one referrer-side control program that only references the variable,
- the system program includes, as an execution preparation process of the control program,
- a process in which a global variable area storing the global variable is generated in the memory;
- and
- a process in which, with respect to each referrer-side control program and for each global variable that is referenced by the referrer-side control program, a synchronous buffer is generated in the memory as a reference destination in place of the global variable area when the referrer-side control program references the global variable,
- the system program includes, as an execution control process of the control program,
- an owner-side start process that starts execution of the owner-side control program;
- a copy process in which, when execution of the owner-side control program ends, the global variable that is rewritten by the owner-side control program is copied from the global variable area to the synchronous buffer corresponding to the global variable;
- and
- a referrer-side start process that starts execution of the referrer-side control program.
A system program for a PLC, the system program being stored in a memory to be executed by a microprocessor in a CPU unit of the PLC, the CPU unit comprising the microprocessor, the memory and a communication circuit and controlling a control target by repeating transmission of output data, reception of input data and execution of a control program that uses the input data to generate the output data, wherein
- the memory store the control program, the system program that controls the execution of the control program, and attribute data of a variable that is used by the control program,
- the microprocessor executes, in addition to the system program, the control program,
- the communication circuit transmits the output data and receives the input data,
- the attribute data include, when the variable is a global variable that is referenced by a plurality of the control programs, information specifying one owner-side control program that rewrites the variable and information specifying at least one referrer-side control program that only references the variable,
- the system program causes the microprocessor to execute, as an execution preparation process of the control program,
- a process in which a global variable area storing the global variable is generated in the memory;
- and
- a process in which, with respect to each referrer-side control program and for each global variable that is referenced by the referrer-side control program, a synchronous buffer is generated in the memory as a reference destination in place of the global variable area when the referrer-side control program references the global variable, and
- the system program causes the microprocessor to execute, as an execution control process of the control program,
- an owner-side start process that starts execution of the owner-side control program;
- a copy process in which, when execution of the owner-side control program ends, the global variable that is rewritten by the owner-side control program is copied from the global variable area to the synchronous buffer corresponding to the global variable;
- and
- a referrer-side start process that starts execution of the referrer-side control program.
A recording medium storing a system program for a PLC, the system program being stored in a memory to be executed by a microprocessor in a CPU unit of the PLC, the CPU unit comprising the microprocessor, the memory and a communication circuit and controlling a control target by repeating transmission of output data, reception of input data, and execution of a control program that uses the input data to generate the output data, wherein
- the memory store the control program, the system program that controls the execution of the control program, and attribute data of a variable that is used by the control program,
- the microprocessor executes, in addition to the system program, the control program,
- the communication circuit transmits the output data and receives the input data,
- the attribute data include, when the variable is a global variable that is referenced by a plurality of the control programs, information specifying one owner-side control program that rewrites the variable and information specifying at least one referrer-side control program that only references the variable,
- the system program causes the microprocessor to execute, as an execution preparation process of the control program,
- a process in which a global variable area storing the global variable is generated in the memory;
- and
- a process in which, with respect to each referrer-side control program and for each global variable that is referenced by the referrer-side control program, a synchronous buffer is generated in the memory as a reference destination in place of the global variable area when the referrer-side control program references the global variable, and
- the system program causes the microprocessor to execute, as an execution control process of the control program,
- an owner-side start process that starts execution of the owner-side control program;
- a copy process in which, when execution of the owner-side control program ends, the global variable that is rewritten by the owner-side control program is copied from the global variable area to the synchronous buffer corresponding to the global variable;
- and
- a referrer-side start process that starts execution of the referrer-side control program.
Dependencies are inferred from the claim text.