JP5494243B2 - Programmable controller and program execution method for programmable controller - Google Patents

Description

  The present invention relates to a technique for speeding up execution of a program such as a programmable controller that controls equipment.

  FIG. 5 is a schematic configuration diagram of a control device that executes a program to control a control target device. The control device includes a microcontroller 500 having a cache memory, and the microcontroller 500 executes a program held in the nonvolatile memory 300 and controls a control target device via an input / output device circuit.

  In order to increase the program execution speed, a high-speed method is known in which an application program held in the nonvolatile memory 300 is rearranged in a high-speed memory such as the RAM 301, and the rearranged program is read and executed.

  As the performance of microcontrollers in recent years has improved, access to the cache memory mounted on the microcontroller can be executed with one or two clocks of the high-speed clock inside the microcontroller, while the access to the external memory as described above. Since access requires 10 to 10 times the access time, there is a method of utilizing the cache of the microcontroller 500 in addition to the above speed-up method.

  When the cache is utilized, the application program rearranged in the RAM 301 is transferred to the processor 501 and executed in conjunction with the fetch operation from the microcontroller 500, and is loaded into the instruction cache memory 502. Thereafter, when executing the program, if the program to be executed is held in the cache memory, the microcontroller 500 executes the program held in the cache memory without fetching the program from the external memory. The execution speed is increased.

  Programmable controllers that represent control devices (hereinafter referred to as PLCs) generally start user applications after power-on or reset start, execute memory clear and various initial settings, and then execute application programs cyclically It is configured to By executing the application program cyclically, the PLC performs control in a predetermined unit time (control cycle).

  FIG. 6 is an execution conceptual diagram of the PLC user application started as described above. In FIG. 6, the execution time of the application program is accelerated from the next execution section P2 since the program is loaded into the instruction cache memory 502 by the first execution (section P1) after the user application is started. High speed is maintained.

JP 2002-99312 A

  However, using the cache memory to increase the program execution speed can reduce the application execution time, but the program execution time fluctuates depending on the cache hit and miss hit. Variation occurs.

  In the first execution (P1) of the user application, since the program is fetched from the RAM 301, the execution time is longer than the second and subsequent execution times (P2, P3). Variations will affect the control cycle.

  Depending on the type of user application, there are not only the execution time of the user application itself, but also applications (motion control represented by positioning control by a servo system, etc.) that require highly accurate control cycle variations. In a PLC that realizes a control function, fluctuations in program execution time cause variations in control speed and control cycle, which causes a problem in that normal control cannot be executed.

  The object (problem) of the present invention has been devised in view of the above problems, eliminates the difference in execution time caused by cache hit / miss hit, and always has a stable unit time (control cycle). It is providing the program execution method of the programmable controller which can be controlled by, and a programmable controller.

As a method for solving the above problems, the present invention is configured as follows.
The invention according to claim 1 is a microcontroller having a cache memory, a user application that is executed by the microcontroller to control an external device, and an execution result of the user application that is activated by the user application is transferred to a storage means. A programmable controller having transfer means for outputting and output means for outputting an execution result held in the storage means to an external device,
Prior to the operation of control, provisional execution means for masking activation of the transfer means and executing the user application and loading the user application into the cache memory is provided.

The invention according to claim 2 is the programmable controller according to claim 1,
The user application is a subroutine program that is activated when a predetermined variable is given and called, and the temporary execution means provides the user application with a variable for prohibiting activation of the transfer means when calling and executing the user application. The user application is configured to execute the program of the user application without starting the transfer means based on a variable for prohibiting the start of the transfer means.

  According to a third aspect of the present invention, in the programmable controller according to the second aspect, the user application is further configured to lock the cache memory upon termination of the user application based on a variable for prohibiting activation of the transfer means. .

According to a fourth aspect of the present invention, the user application includes a sequence control program that controls the external control device at predetermined intervals.
In the invention according to claim 5, the user application is configured by a positioning control program for executing positioning control.

In the invention according to claim 6, the user application is constituted by a program of a compiler type language.
The invention according to claim 7 is the programmable controller according to any one of claims 1 to 6, wherein the user application is held in a non-volatile memory, and the programmable controller stores a user application held in the non-volatile memory, Program update means for updating to a user application for update transferred from a programming device detachable from the programmable controller is provided.

According to an eighth aspect of the present invention, there is provided a microcontroller having a cache memory, a user application that is executed by the microcontroller to control an external device, a working memory of the user application, and a user application that is activated by the user application. A program execution method for a programmable controller having transfer means for transferring execution results to storage means, and output means for outputting execution results held in the storage means to an external device,
Initialize the working memory and storage means, load the user application to the cache memory by executing the user application while masking the activation of the transfer means, lock the cache memory, reinitialize the working memory, Configure to execute the user application with permission to start.

  The programmable controller of the present invention temporarily executes the user application prior to operating the control. In other words, since the user application is executed without performing actual control and the user application is loaded and locked in the cache memory, high speed can be exhibited from the first execution of the user application during operation, and the program The execution time and control cycle are extremely stable.

  Therefore, the present invention provides a programmable controller capable of eliminating the difference in execution time caused by cache hit / miss hit and always performing control with a stable control cycle.

System configuration diagram of programmable controller according to the present invention Functional block diagram of a programmable controller according to the present invention The flowchart which shows the initial process of the programmable controller which concerns on this invention Operation | movement conceptual diagram with which the programmable controller which concerns on this invention performs a user application Schematic configuration diagram of a general control device that controls a control target device Execution concept diagram of user application of control device according to FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a control system according to an embodiment of the present invention.
As shown in FIG. 1, in this control system, a programmable controller (hereinafter referred to as “PLC”) 20 is connected to an external control device 32 via an input / output module 23 and communicates with a definition setting loader 30 (for example, General-purpose serial communication) 31.

  The PLC 20 includes a CPU (Central Processing Unit) module 10. The CPU module 10 includes a CPU 11, a program memory 12 such as a nonvolatile memory, a system work memory (RAM (Random Access Memory)) 13, an input / output memory (RAM) 14, an application memory (RAM) 15, and a definition setting loader. A driver / receiver 16 for communicating with 30 and a bus interface 17 for interfacing with an input / output module are connected by a bus 19. Further, the CPU 11 is equipped with an instruction cache 11b and a data cache 11c for executing a program at high speed.

  The PLC 20 starts a user application held in the program memory 12 after system initialization after power-on or reset start, and then executes the user application cyclically to perform control at a predetermined control cycle. It is configured. That is, the user application dealt with in the present invention is intended for a sequence control program for controlling an external control device at a predetermined control cycle as an example.

  The definition setting loader 30 has a function of compiling a source program programmed by a user and generating an execution code (compiler language) that can be directly executed by the CPU 11 of the PLC 20. Then, the execution code is downloaded to the CPU module 10 via the communication line 31, so that the CPU module 10 updates the user application previously held in the program memory 12 or the like to the downloaded execution code ( Program update means).

FIG. 2 is a functional block diagram of the PLC 20. The function of the PLC 20 according to the present invention will be described with reference to FIG.
The PLC 20 includes an initial function 200 that initializes the PLC 20, a user application 202, an input / output control function 203 that interfaces with the external control device 32, and a system function 201 that operates the entire PLC 20. The initial function 200 includes an application temporary execution function 200 a for temporarily executing the user application 202, a memory clear function (not shown) for initializing data held in the RAM, and an operation parameter for the input / output control function 202. An input / output control function initialization function (not shown) is provided. The system function 201 also includes an I / O data transfer function 201a for transferring output data calculated and output by the user application 202 to the input / output control function 203, status information (state information), and the like in the system work memory. A state information transfer function 201b for transferring is provided.

The system work memory 13, the input / output memory 14, and the application memory 15 are the same as those described in FIG.
The user application 202 is a program that is converted into a subroutine, and is configured to receive a variable when it is called and to execute processing corresponding to the given variable.

  Here, the movement when the PLC 20 is in the operating state will be described. The user application 202 executes an application program when a system call is made by the system function 201. Then, the user application 202 calls the I / O data transfer function 201a (corresponding to a driver for transmitting data) in order to reflect the output data calculated and output at the time of execution in the external control device 32.

  The called I / O data transfer function 201 a transfers the output data to the input / output memory 14. The input / output control function 203 outputs the transferred output data to the external control device 32 via the input / output module 23.

  At this time, the system function 201 gives the above-mentioned variable “1” to the user application 202 when a system call is made to the user application. Upon receiving the variable “1”, the user application 202 executes the application program and calls the I / O data transfer function 201a.

  That is, in the operating state, the user application 202 is given the variable 1 by the system function 201, executes the application program for each system call, and transfers data between the user application 202 and the input / output control function 203. The / O data transfer function 201a is called, and output data that is the result of the sequence calculation is output to the external control device 32.

  FIG. 3 is a flowchart showing processing (initial function) from when the PLC 20 is activated until it reaches the operating state. The point of the present invention is that the user application provisional execution function (S101) is executed prior to operating the PLC 20 (that is, during initial processing).

  In FIG. 3, after power-on or reset start, the initial function 200 clears data such as RAM (S100), and then temporarily executes a user application (S101). This provisional execution is to execute the user application without controlling the external control device 32, and is achieved by giving the variable “0” to the user application 202 and calling it.

  The user application 202 called with the variable “0” executed executes the application program, but ends without calling the I / O data transfer function 201a. If the I / O data transfer function 201a is not called, the I / O data is not reflected on the external control device 32, so that the user application 202 can be executed without actual control. .

  Further, the user application 202 is called with a variable “0”, thereby locking the instruction cache memory 11b simultaneously with the end of the program. Since the contents of the instruction cache memory 11b are not updated after the cache is locked, the application program held in the instruction cache memory 11b is fetched when the user application is executed thereafter.

  In this way, the user application 202 executes the application program without performing actual control, and the executed application program is loaded into the instruction cache memory 11b and locked. Therefore, when the user application 202 is executed after the PLC 20 is in an operational state, the user application program is fetched from the instruction cache memory, so the PLC 20 can execute the program at high speed from the first activation of the formal application. Can be executed.

  Subsequently, the initial function 200 performs the memory clear again and sets various initial values (S102). The reason for re-clearing the memory in step S102 is to prevent the work data when the user application temporary execution function (S101) is executed from affecting the control operation in the operating state of the PLC 20. . At this time, as in the memory clear executed in step S100, the data in all areas constituted by the RAM or the like may be cleared, but the memory may be cleared only for the application memory 15. In (S101), since only the application memory 15 is handled as the working memory, it is not necessary to clear the area other than the application memory 15 by re-clearing the memory in step S102, and the initial process is quickly terminated and the PLC 20 This is because it can be put into an operational state.

  Subsequently, the initial function 200 initializes the input / output control function by giving operation parameters and the like to the input / output control function 203 (S103). Thereafter, the initial function 200 instructs the system function 201 to make a system call to the user application, and formally activates the user application 202 (S104). Based on this instruction, the system function 201 periodically makes a system call to the user application 202 by setting the variable to be given to the user application to “1”.

  FIG. 4 is a conceptual diagram of an operation in which the PLC 20 that is in an operational state through such initials executes a user application. As described above, since the user application 202 is temporarily started after being temporarily executed, the program is loaded and held in the instruction cache at the time of temporary execution. Accordingly, the processing is performed at high speed from the first execution (section P1) after the application is started, and the high speed is maintained and stable thereafter. That is, according to the present invention, the PLC 20 can execute high-speed performance from the first section P1 where the application is started, and can perform extremely stable control without any disturbance in the control cycle.

  That is, as described above, the point of the present invention is that a memory area (application memory) operated by a user application when the user application is executed as a preprocess (preparation process) until control operation and loaded into the cache memory. ) To mask the activation of the transfer to the memory area (input / output memory) for output to the external device.

  Since the access to the application memory 15 is mostly performed by the user application 202 (mainly for user application work), the system work memory 13 and the input / output memory 14 accessed under the system function 201 are physically It is better to use another memory.

Since access to the system work memory 13 and the input / output memory 14 is mostly performed by the system function 201, the memory of one medium may be divided into areas.
The variable “0” given to the user application is a parameter that prohibits the calling of the I / O data transfer processing 201 a and locks the cache at the end of the user application. The variable “1” is the I / O data. This parameter allows the data transfer process 201a to be called.

  Further, the PLC 20 according to the present invention can be applied to motion control in which a servo or the like is connected as an external control device by using the user application as a positioning control program and the input / output module 23 as a positioning control module. As described above, the programmable controller according to the present invention is extremely stable in program execution time and control cycle, and therefore can perform highly reliable control even in applications such as motion control that require highly accurate control cycle variation. it can.

DESCRIPTION OF SYMBOLS 10 CPU module 11 Microcontroller 11a Central processing part 11b Instruction cache memory 11c Data cache memory 12 Program memory 13 System work memory 14 Input / output memory 15 Application memory 16 Driver / receiver 20 Programmable controller (PLC)
23 Input / output module 30 Definition setting loader 32 External control device 200 Initial function 200a Application temporary execution function 201 System function 201a I / O data transfer function 201b Status information transfer function 202 User application 203 Input / output control function

Claims (8)

A microcontroller having a cache memory;
A user application that is executed by the microcontroller to control an external device;
Transfer means that is activated by the user application and transfers an execution result of the user application to a storage means;
Output means for outputting the execution result held in the storage means to the external device, and a programmable controller comprising:
Prior to operation of control, a programmable controller comprising provisional execution means for masking activation of the transfer means, executing the user application, and loading the user application into the cache memory. The programmable controller according to claim 1,
The user application is a subroutine program that is activated when a predetermined variable is given and called,
The provisional execution means, when calling and executing the user application, gives the user application a variable for prohibiting activation of the transfer means,
The programmable controller, wherein the user application executes a program of the user application without starting the transfer unit based on a variable for prohibiting the transfer unit from being started. The programmable controller according to claim 2,
The user application further locks the cache memory upon termination of the user application based on a variable for prohibiting activation of the transfer means. The programmable controller according to any one of claims 1 to 3,
The programmable controller, wherein the user application is a sequence control program for controlling the external control device at predetermined intervals. The programmable controller according to any one of claims 1 to 3,
The programmable controller characterized in that the user application is a positioning control program that executes positioning control. In the programmable controller according to any one of claims 1 to 5,
The programmable controller according to claim 1, wherein the user application is a compiler language program. The programmable controller according to any one of claims 1 to 6,
The user application is held in a non-volatile memory;
The programmable controller further includes program update means for updating the user application held in the nonvolatile memory to an update user application transferred by a programming device detachable from the programmable controller. Programmable controller. A microcontroller having a cache memory;
A user application that is executed by the microcontroller to control an external device;
A working memory of the user application;
Transfer means that is activated by the user application and transfers an execution result of the user application to a storage means;
Output means for outputting the execution result held in the storage means to the external device, and a program execution method for a programmable controller comprising:
The working memory and the storage unit are initialized, the user application is executed by masking activation of the transfer unit, the user application is loaded into the cache memory, the cache memory is locked, and the working memory After reinitializing
A program execution method for executing the user application while permitting activation of the transfer means.