JPS6217803A - Control system for programmable controller - Google Patents

Abstract

PURPOSE:To improve the efficiency of sequence control by processing the 2nd and 3rd programs on the basis of a ratio set up by the 2nd setting means. CONSTITUTION:A stored program type programmable controller such as a numerical controller for a machine tool executes control on the basis of a program stored in a memory 1. The memory 1 includes storing areas for a sequence program a described by a ladder type program, a program B for screen display and a program C described by high level language such as Pascal and sets up the priority levels of respective programs A-C to A>B>C. In addition, the 1st setting means 2 for setting up the processing execution time of the sequence program A within a unit time, the 2nd setting means 3 for setting up the processing execution ratio of the programs B, C and a control means 4 for the programs A-C to execute the programs B, C on the basis of the execution ratio during the residual time of the execution of the program A.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control system for a programmable controller that performs sequence control on a numerically controlled machine tool.

(Prior art) Conventionally, a strong electric circuit consisting of a group of many relays has been interposed between the numerical control device side and the machine tool side, and a predetermined relay is operated in response to a command from the numerical control device, thereby responding to the command. However, as mentioned above, when a strong electric circuit is involved, the device becomes larger and requires a large number of relays, which leads to higher costs. .

Therefore, so-called stored program programmable controllers that realize the functions of high-voltage circuits through program processing are increasingly being used.

Such stored programmer type programmable controllers generally store a ladder-type sequence program in memory, and the processor executes the sequence program to control the sequence of the machine. . A ladder-type sequence program is one in which the functions of a high-voltage circuit are logically programmed using instruction codes. For example, as shown in Figure 6 (A),
The ladder one-way sequence program corresponding to the ladder diagram that is part of the high-voltage circuit shown by the relay contacts and relay coil shown in Figure (B) is the one shown in Figure (B).Here, RD, 8ND, WRT, ORNOT, etc. are each instruction codes, RD is a continuation instruction, AND is a logical product operation instruction, WRT is a write instruction, OR is a logical sum operation instruction, ORNO
T is a logical OR operation instruction with a negative value. Also, 10.0
．． 200.1, etc. are addresses (predetermined locations, predetermined bits) on the data memory at which the instruction code is executed. By executing the instructions of this sequence program, (a7b)+
The logical operation of c is executed, and the result of the operation (“1” or 0”) is stored in the first bit of address 210 of the data memory.

If we describe this as the behavior of a high-voltage circuit in 1-4-4, relay contact a
, b, and c, the relay coil d is excited.

A programmable controller generally performs logical operations according to the ladder-type sequence program as described above and performs sequence control of the machine, but it also performs diagnosis and execution of programs written in high-level languages such as Pascal or assembler language. Performs screen display processing to display data and installation data on a CRT screen.

Here, when executing a program written in a high-level language such as Pascal or assembler language, it is difficult to write processes such as four arithmetic calculations and functional operations in a ladder-type program. It is from.

Figure 7 is an explanatory diagram of the operation of a conventional programmable controller that executes a program written in a high-level language such as Pascal or assembler language i, as described above. be. It should be noted that the priority levels of each process (■) to (■) are ■>■>■.

As can be seen from the figure, in conventional programmable controllers, ladder-type program execution and screen display processing are performed alternately until the display processing for one screen is completed. After the program is finished, the program is alternately executed using a ladder program and a program written in a high-level language such as Pascal or assembler language. Note that the execution time P of the ladder-type program within a unit period can be set arbitrarily. In the conventional method, a program written in a high-level language such as Hakohaskal or assembler language cannot be executed until after the screen display processing for one screen is completed. When it is necessary to execute many written programs, there is a problem that sequence control cannot be performed efficiently.

[Problem that the invention seeks to solve]

The present invention solves the above-mentioned problems, and its purpose is to efficiently perform sequence control even in sequence control that requires the execution of many programs written in a high-level language or assembler language. The goal is to make it possible.

[Structure of the invention]

In order to solve the above-mentioned problems, the present invention employs a stored program method in which a program is stored in a memory 1 and control is performed according to the program stored in the memory 1, as shown in FIG. In the programmable controller, a first program, a second program, and a third program each having a different priority level are stored in the memory 1, and a program execution time of the first program within a unit time is set. 1 setting means 2; and the second setting means 2; a second setting means 3 for setting an execution ratio of processing by a third program; A management means 4 for managing the second and third programs is provided, and the management means 4 performs processing by the first program for the time set by the first setting means 2 within the unit time. At the same time, the processing by the second or third program is executed during the remaining time based on the execution ratio set by the second setting means 3.

[For production]

2nd at the ratio set by the second setting means 3. Since the processing is performed by the third program, it is efficient even when executing sequence control that requires the use of a large number of the third programs or sequence control that does not require the use of the third program much. can be made higher.

〔Example〕

FIG. 2 is a block diagram of an embodiment of the present invention, in which 10 is a numerical control device, 20 is a programmable controller, 3
0 is a machine tool, 11 is a processor, 12 is a memo, 13
is a tape league, 14 is a command tape, 15 is a keyboard, 16 is a display device, 17 is a distribution pulse Xp to the servo circuit
, Yp, and 18 is an R shared by the numerical controller IO and the programmable controller 20.
AM, 21 is the processor, 22 is the memory, and the edict isometrically indicates the on/off status of each relay in the high-voltage circuit as "1".
, 0'', and 24 is an input/output section.As shown in FIG. Area #A where (hereinafter referred to as sequence program A) is stored
, area #B where a screen display program (hereinafter referred to as screen display program B) is stored, and area C where a program written in a high-level language such as Pascal or assembler language is stored. It is provided. Furthermore, the priority levels of each program A, B, and C are A>B>C.

Further, FIG. 4 is a flowchart showing part of the processing contents of the processor 21 in the programmable controller 20, and the operation of FIG. 2 will be explained below with reference to the same figure.

The process shown in the flowchart of FIG. 4 is performed every unit time T (for example, 8 m5ec), and in step SO it is determined whether or not to execute the sequence program. An execution request occurs when a fixed cycle or sequence program is urgently processed. In step S1, it is determined whether the flag F is "1", that is, whether the processing by the screen display program B is being executed or the processing by the program C written in a high-level language or assembler language is being executed. . If the determination result in step S1 is YES, the processor 21 interrupts the processing by the screen display program B (step S2), and then stores the return information of the screen display program B (for example, , the address of the memory 22 where the instruction being executed at the time of the interruption is stored is stored (step S3), and then the process moves to step S6. Further, if the judgment result of the chip S1 is No, the processor 21 interrupts the processing by the program C (step S4), and then stores the return information of the program C in the register C provided inside the processor 21 (step S5).
), then the process moves to step S6.

Note that flag F is "0" in the initial state (when the power is turned on).
cents.

The processor 21 has a register A provided therein.
In step s6), when the return information of the sequence program A stored in is read, the timer is set to the execution time Tx of the processing by the sequence program A (Tx < T, and is input from the keyboard 15, for example. ) is set in step S7), then step S
Processing by sequence program A is restarted based on the return information read in step S8 (step S8). After that, when it is determined that the timer has timed up, that is, when it is determined that the processing by the sequence program A has been performed for a period of time T (step S9), the processor 21 interrupts the processing by the sequence program A (step 5IO). Then, the return information of sequence program A is stored in register 8 (step 511).

When the process of step 311 is completed, the processor 21 adds the numerical value DC stored in the register D provided inside the processor 21 and the numerical value P stored in a predetermined area of the RAM 1B, and transfers the addition result to the register D. Store it in (
Step 512). Here, P is the sum of the processing by screen display program B and the processing by program C, which is 10
It represents the execution ratio (%) of processing by program C when 0 (%) (O≦P≦100), and is input from, for example, the keyboard 15 and stored in a predetermined area of the RAM 1B. Note that in the initial state, register D stores O.

When the process of step 312 is completed, the processor 21 determines that the numerical value DC stored in the register D is DC, <100.
In step 51, it is determined whether or not the relationship is satisfied.
3) If the judgment result is YES, set flag F to "1"
Step 314), then step 12) Read screen display program B (Dffl return information) from register B (step 316), then step 315
Screen display program B based on the return information read in
The process is restarted (step 316).

Further, if the judgment result in step 313 is NO, the processor 2] returns 1 from the numerical value DC stored in the register D.
00 is subtracted and the subtraction result is stored in register D (step 317), then the flag F is set to ``0'' (step 318), the return information of program C is read from register C (step 519), and then step 319
Processing by program C is restarted based on the return information read in (step 520).

Therefore, if the execution ratio P of the processing by program C is set to, for example, 4%, the determination result in step 313 will be YES only once in five cycles.
The processing by the sequence program A1, the screen display program B, and the program C will be performed at the ratio shown in FIG. 5(A).

Furthermore, if the execution ratio P is set to (capital)%, the judgment result in step 3.13 is YES four times out of five cycles, so the sequence program A1 screen display program B and The processing by program C will be performed at the ratio shown in FIG.

In this way, according to this embodiment, the processing by the screen display program B and the processing by the program C are performed at an execution ratio P.
It can be executed at a ratio according to Sequence control can be efficiently performed when a large number of processes are required using the written program C.

〔Effect of the invention〕

As explained above, the present invention provides a stored program type programmable controller in which a program is stored in a memory and control is performed according to the program stored in the memory. Different first. The second and third programs (sequence program A, two-screen display program B, and program C in the embodiment) are stored, and the execution time of the processing by the first program within a unit time (in the embodiment) is stored. Tx); a second setting means for setting an execution ratio (P in the embodiment) of processing by the third program; a management means for managing the second and third programs, and the management means performs processing by the first program for the time set by the first setting means within the unit time, and for the remaining time. time based on the execution ratio set by the second setting means.
Or, because the process is executed by the third program, it is a sequence control that requires the use of a lot of program C written in a high-level language such as Pascal or assembler language, or a sequence that does not require much use of program C. There is an advantage that efficiency can be increased even when executing control.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the present invention, FIG. 2 is a block diagram of an embodiment of the present invention, FIG. 3 is a diagram showing the contents of memory, and FIG.
The figure is a flowchart showing the processing contents of the processor 21,
FIG. 5 is an explanatory diagram of the operation of FIG. 2, FIG. 6 is a diagram showing a ladder diagram and a sequence program corresponding thereto, and FIG. 7 is an explanatory diagram of the operation of the conventional example. 1 is the memory, 2 and 3 are the first . second setting means,
4 is a management means, 10 is a numerical control device, 20 is a programmable controller, 30 is a machine tool, 11 is a processor, 12 is a memory, 13 is a tape league, 14 is a command tape, 15 is a keyboard, 16 is a display device, 17 is A pulse distribution circuit that outputs distribution pulses Xp and Yp to the servo circuit, 18 a RAM shared by the numerical control device 10 and the programmable controller 20, 21 a processor, 22 a memory, a data memory 24, and an input/output section. be.

Claims (3)

[Claims] (1) In a stored program type programmable controller that stores a program in a memory and performs control according to the program stored in the memory, the memory has a first, a second, and a second controller having different priority levels. a first setting means for storing a third program and setting an execution time of processing by the first program within a unit time; and setting an execution ratio of processing by the second and third programs; a second setting means for managing the first, second and third programs; and a management means for managing the first, second and third programs; A programmable controller characterized in that the programmable controller executes the processing according to the first program, and also executes the processing according to the second or third program based on the execution ratio set by the second setting means for the remaining time. control method. (2) The second setting means sets the total of the processing by the second program and the processing by the third program to 1.
2. The control method for a programmable controller according to claim 1, wherein a numerical value indicating an execution ratio of the third program is set when the execution ratio is set to 00%. (3) The management means has a register in which the numerical value set by the second setting means is cumulatively added each time the processing by the second program is executed, and the numerical value stored in the register is If the value was less than 100, the process by the second program was executed, and if the value stored in the register was 100 or more, the value obtained by subtracting 100 from the value stored in the register was stored in the register. 3. A control system for a programmable controller according to claim 1, wherein the programmable controller control method further comprises executing processing by said third program.