JP2000357004A - Programmable controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a programmable controller with which a user can freely and surely control the timing of a program change in real time. SOLUTION: Concerning the programmable controller composed of a microcomputer 6 capable of executing sequence control, a memory 1 for storing control contents as a user program and an input/output interface or bus 7 for inputting/outputting an external signal, this device is equipped with a register part 4 capable of presetting comparison conditions from the outside, a comparator circuit element 2 for outputting an interruption signal 5 at the time of condition establishment is provided separately from the microcomputer 6 and when the interruption signal 5 outputted from the comparator circuit element 2 is recognized, even while the user program is run, the microcomputer 6 temporarily stops user program processing under execution at present and executes a change condition establishment discrimination routine under RUN.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller for executing a desired sequence control by executing a user program transferred by communication from an external peripheral device, and more particularly to executing a user program (during RUN). And a programmable controller capable of changing the program.

[0002]

2. Description of the Related Art In a conventional programmable controller (hereinafter simply referred to as "PLC"), an arithmetic unit executes control contents of an arithmetic unit according to a sequence program as a user program stored in a part of a memory unit. When the content is changed, it is rewritten to a user program transferred from an external peripheral device by a communication function. By the way, at this time, the user usually attaches the PLC and peripheral devices (such as a personal computer) to the 11RS-232C.
Online via a communication interface such as
The peripheral device instructs the PLC to change the user program.

At this time, conventionally, an instruction to change the user program is input from the keyboard or the like from the peripheral device, and information (user program to be changed) is transmitted to the PLC by the communication function. On the other hand, the PLC receiving this does not immediately perform the change processing of the program,
This program change process has been performed only after one cycle of the running user program has been executed, that is, only at a certain period. Note that such a conventional PL
An example of the change of the user program in C is, for example,
It is already known from Japanese Patent Application No. 8-57431.

However, in the above-described conventional technology, the time required from when a peripheral device instructs the PLC to change the user program to when the user program in the PLC is actually changed is various. Depends on the conditions. This makes it difficult for the user to predict the timing of changing the user program.

In some cases, a user program is changed during execution. The reason for changing the program during the execution of the user program is, for example, the reason that it is necessary to execute the changed program while retaining information (for example, control parameters and the like) of the program execution result up to that time. For. In addition, since the changed program is executed with the information of the program execution result up to that time, there is a case that it may not be possible to predict how the operation being executed is affected.

As an example, it is assumed that, for example, if a program is changed while a PLC is controlling a belt cotton belt, the belt conveyor remains operating, and a stop process cannot be performed by receiving a stop position detection signal. Is done. However, if the program being changed is stopped after the article being transported is stopped at a predetermined position, the program change does not cause the belt conveyor to be operated and cause the article to collide.

Thus, for example, Japanese Patent Application No. 9-24471 proposes a control device that can change a program in real time after storing the program, and can arbitrarily specify a change timing and a change condition of the program. Are known. In this prior art, the change timing and the change condition of the program can be arbitrarily specified. However, the establishment of the change timing and the change condition is performed by a control device that changes a part of the operating program on the PLC side to a new program. On the side (ie, the peripheral device side), for example, based on contact input information and time information of a specific contact,
This is determined by software.

[0008]

That is, in the above-mentioned prior art, it is possible to arbitrarily designate a change timing and a change condition of a program. Is determined by software based on, for example, contact input information or time information of a specific contact on the control device side (that is, the peripheral device side) that changes a part of the program into a new program.

Therefore, in order to detect the timing of the change and the satisfaction of the change condition on the peripheral device side (for example, by a personal computer or the like) which edits and changes the user program, the operation is particularly performed on the PLC side. When the satisfaction of the condition is detected, the condition on the PLC side (for example,
It is necessary to transfer the contact input information of a specific contact to the peripheral device side, and it is still difficult to change the program in real time. In addition, the load on the arithmetic unit on the control device side is increased, which again makes it difficult to control the change timing of the user program in real time, so that the user can freely control the timing of the program change.

In view of the above-mentioned problems in the prior art, the present invention provides a programmable controller which allows a user to freely and reliably control the timing of program change in real time. It is an object of the present invention to provide a programmable controller which allows a user to easily perform a change timing when a program is changed during execution of a program (during RUN).

[0011]

According to the present invention, in order to achieve the above-mentioned object of the present invention, an arithmetic unit capable of executing sequence control, and a control program of the arithmetic unit as a user program in the form of a sequence program In a programmable controller composed of a memory unit storing at least a part of the memory unit and an input / output interface unit for inputting / outputting an external signal for the control, further, comparison conditions can be set from outside in advance, and A comparator circuit element that outputs an interrupt signal to the arithmetic device when the condition is satisfied, provided separately from the arithmetic device;
When the arithmetic unit recognizes the interrupt signal output from the comparator circuit element, it temporarily suspends the currently executing user program process even during the execution of the user program, and executes a RUN change condition satisfaction determination routine. There has been proposed a programmable controller configured to execute and change a user program in accordance with a result of a determination made by the RUN change condition satisfaction determination routine.

Further, according to the present invention, in the above-mentioned programmable controller, the comparator circuit element has a register section, and the comparator circuit element compares the condition based on a comparison condition set in advance in the register section from outside. It is configured to perform an operation.

Further, according to the present invention, in the programmable controller described above, the comparator circuit element compares an access address in the memory section based on a comparison condition set in the register section, and satisfies the condition. It is configured to perform a comparison operation.

According to the present invention, in the programmable controller described above, a bus is further provided between the arithmetic unit and the memory unit, and the comparator circuit element is connected via the bus. The memory unit is configured to compare access addresses.

In addition, according to the present invention, in the programmable controller described above, the register section of the comparator circuit element is configured so as to be set corresponding to a dedicated instruction of a user program created by a user. ing.

That is, according to the present invention, a hardware (comparator circuit element) for comparing the access address of the internal memory of the PLC is provided, and an interrupt signal is output to the microcomputer of the PLC based on the information of the comparator circuit element 2.
Activate the UN change condition satisfaction determination routine (interrupt software) to determine whether the RUN change condition 8 is satisfied,
If the condition is satisfied, the user program can be changed immediately.

Further, according to the present invention, a dedicated instruction for executing the change during RUN is provided, and the execution condition of the dedicated instruction is set in a user program (combination of contact input / output information, internal input / output information, internal time data, etc.). Can be specified.

[0018]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 2 shows an external view of a programmable controller (hereinafter simply referred to as a PLC) 10 according to an embodiment of the present invention and communication means for changing a sequence control program executable by the PLC. , 1
A peripheral device (for example, a personal computer or the like) 11 connected online via a communication interface 12 such as 1RS-232C is shown.

FIG. 1 shows a specific hardware configuration of a PLC 10 according to an embodiment of the present invention. As is apparent from FIG. A computing unit for performing control, such as a microcomputer (hereinafter simply referred to as a microcomputer) 6 or the like, and storage means for partially storing sequence control as a sequence program executable by the computing unit, such as a RAM And a bus 7 provided therebetween. The microcomputer 6 executes PLC sequence control while accessing a predetermined address in the memory unit 1 according to a program (in the figure, an access address of the memory unit 1 is indicated by reference numeral 3). Become.

Although not shown in FIG. 1, an input / output interface (11RS) for inputting / outputting an external signal transmitted by communication from an external peripheral device (personal computer).
And a terminal to which a communication interface such as −232C is connected), and the input / output interface unit is also connected to the bus 7.

In the present invention, in the above configuration, a comparator circuit element 2 comprising a semiconductor circuit chip element as a hardware device is further provided, and the comparator circuit element 2 is also connected to the bus 7. Is connected between the microcomputer 6 and the memory unit 1 via the. The comparator circuit element 2 is for comparing the access address 3 of the memory unit 1, and as apparent from the figure, the comparator circuit element 2 is partially set by the user in advance. A possible register unit 4 is provided. Thus, the comparator 2 monitors the access address 3 corresponding to the register value of the register section 4.

That is, when the access address 3 of the memory unit 1 matches the value to the set address,
The comparator circuit element 2 generates an interrupt signal 5 for notifying the microcomputer 6 of a condition match.

As described above, in the above-described configuration of the PLC 10, by further providing the comparator circuit element 2 composed of a semiconductor circuit chip element as a hardware device,
Since the program change condition on the PLC 10 side can be reliably and promptly determined, the user can control the change timing of the user program in real time.

FIG. 3 is a flowchart showing the processing contents of the microcomputer 6 after receiving the interrupt signal 5 from the comparator 2. When the microcomputer 6 recognizes the interrupt signal 5 from the comparator circuit element 2, this process is interrupted and executed even if the user program is being executed.

That is, as shown in FIG.
After receiving the interrupt signal 5 (IREQ), first, the currently executing user program is temporarily suspended, and the RU
The N-time change condition satisfaction determination routine (interrupt software) is executed (step S1), and then it is determined whether the change condition is satisfied (step S2). As a result of the determination in step S2, the change condition is satisfied (that is, “YE
If "S") is determined, a program change to the user program transferred from the peripheral device 11, that is, the user program to be changed is started (step S3). When the program change is completed, the process returns to the main routine (step S4). If it is determined that the change condition is satisfied (ie, "NO") as a result of the determination in step S2, the process also returns to the main routine (step S4).
It will be.

Next, the RUN change condition satisfaction determination routine showing the above flow is started (that is, IR
An example of a dedicated instruction will be described as a means for outputting the EQ). A user program which transfers control contents to the PLC 10 as a sequence program and enables the PLC to perform sequence control can be edited by an external peripheral device 11 (personal computer). For example, as an example, a so-called ladder A program is known, and an example of the ladder program will be described with reference to FIG.

That is, according to the ladder program, the user can execute a predetermined process (“EN” in the example of FIG. 4).
D)), a “run-time change condition satisfaction determination routine” is set, and the activation condition is further set to RUN by the program including the contact input / output information 8 (contact R0 and contact R100 in this example). A dedicated instruction 9 (broken line in the figure) for the medium change condition satisfaction determination routine is set. In addition,
In addition to the contact input / output information, which is a start condition, a combination of internal input / output information, internal time data, and the like may be used. That is, according to such a ladder program, the dedicated instruction 9 is used as a determination unit of the RUN change condition satisfaction determination routine.
Is provided to the user, whereby the user sets the start condition for executing the change during the RUN by using the user program of the dedicated instruction 9 (for example, a combination of the contact input / output information, the internal input / output information, the internal time data, etc.). ) Allows the change timing to be freely specified.

When it is determined that the above-mentioned start condition is satisfied, the PLC 10 changes the program at that time, and when the condition is not satisfied, executes the temporarily suspended user program. To resume.

In the example shown in FIG. 4, the state in which the contact points R0 and R100 are closed is determined to be the satisfaction of the RUN change condition. On the other hand, along with the user program to change,
The program including the above-described RUN change condition satisfaction determination routine is transferred from the peripheral device (for example, a personal computer) 11 connected online via the communication interface 12 to the PLC 10. At this time, corresponding to the contact point R0 and the contact point R100 which are the RUN change condition satisfaction determination conditions,
The access address 3 in the memory 1 accessed by the microcomputer 6 on the PLC 10 is set in the register section 4 of the comparator circuit element 2.

[0031]

As is clear from the above detailed description, according to the programmable controller of the present invention, the user can freely and reliably control the timing of changing the program in real time. When a program is changed during execution of a user program (during RUN), it is possible for the user to easily perform the change timing, thereby expanding the field of use of the programmable controller and improving the program change. In this case, an excellent effect that the burden on the user can be significantly reduced is exhibited.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an example of an internal hardware configuration of a programmable controller according to the present invention.

FIG. 2 is a diagram showing a state where the above-mentioned programmable controller is connected to a peripheral device for program change.

FIG. 3 is a flowchart showing a control flow when a program is changed in the programmable controller of the present invention.

FIG. 4 is a diagram showing an example of a dedicated instruction for setting a user program change condition satisfaction determination condition in a programmable controller according to the present invention by a ladder program.

[Explanation of symbols]

 1 memory 2 comparator circuit element 3 access address 4 register section 5 interrupt signal 6 microcomputer (control section) 7 bus

Claims (5)

[Claims] An arithmetic unit capable of executing sequence control, a memory unit for storing at least a part of a control content of the arithmetic unit as a user program in the form of a sequence program, and an external signal for inputting the control. In a programmable controller comprising an input / output interface unit for outputting, further, a comparison condition can be set in advance from the outside, and a comparator circuit element for outputting an interrupt signal to the arithmetic unit when the condition is satisfied is provided. The arithmetic device is provided separately from the arithmetic device, and when the arithmetic device recognizes the interrupt signal output from the comparator circuit element, the user program process currently being executed is suspended even while the user program is being executed. The RUN change condition satisfaction determination routine is executed, and the RUN change condition is determined. A programmable controller configured to execute a change of a user program in accordance with a result of determination by a case satisfaction determination routine. 2. The programmable controller according to claim 1, wherein said comparator circuit element includes a register unit, and said condition comparing operation is performed based on a comparison condition set in advance in said register unit from outside. A programmable controller configured to perform the following. 3. The programmable controller according to claim 2, wherein the comparator circuit element comprises:
A programmable controller configured to compare an access address in the memory unit based on a comparison condition set in the register unit and perform a comparison operation of the condition. 4. The programmable controller according to claim 3, further comprising a bus provided between said arithmetic unit and said memory unit, wherein said comparator circuit element is connected to said memory unit via said bus. A programmable controller configured to compare the access addresses of the programmable controllers. 5. The programmable controller according to claim 2, wherein the register section of the comparator circuit element is configured to be set in accordance with a dedicated instruction of a user program created by a user. Features a programmable controller.