JPH0764469A - Programmable controller - Google Patents

Abstract

PURPOSE:To cause a PLC to run a sequence program at high speed that includes contact input commands such as LD commands. CONSTITUTION:In the case of a contact input command of 'LD 000000', '0' is set in the command as save information, and since this indicates that a PF value need not be saved, when the command is executed 'X' stored in the PF value by the previous command is not saved in a stack S1. In the case of a contact input command of 'LD 000002', '1' is set as save information in the command, and since this indicates that the PF value need be saved, when the command is executed 'A+B' stored in the PF value by the previous command of 'OR 000001' is saved in the stack S1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller that executes a sequence program including instructions such as contact input instructions.

[0002]

2. Description of the Related Art As a programmable controller (hereinafter referred to as PLC) for executing a sequence program with a general-purpose microprocessor, an interpreter system for sequentially decoding and executing the sequence program, and a sequence program which is expanded into MPU instructions in advance and executed. Some are compiled.

In such a PLC, normally, as shown in FIG. 12, a bit operation register PF (also referred to as a power flow) and a stack Sn for saving a value of the bit operation register PF (hereinafter referred to as a PF value). (N = 1,2, ...)
And are composed of general-purpose registers. When processing a contact input instruction such as a load instruction (hereinafter referred to as an LD instruction) in a sequence program, the PF value is always saved in the stack first as shown in FIG.
0), and then the contact information read from the I / O memory is set in the bit operation register PF (step 20).

[0004]

However, in such a conventional programmable controller, when executing the contact input instruction in the sequence program, the intermediate result of the bit logical operation which has been executed every time is always stacked. Since the data is saved in S1, even intermediate results that are not used later may be saved, which causes a problem of reducing the processing speed in sequence control that requires high speed.

More specifically, for example, referring to FIG.
When executing the sequence program SP represented by the ladder chart as shown in FIG.
When the input contact information A to D in the memory is set, the bit operation operation by the bit operation register PF is as shown in FIG.

That is, in FIG. 16, the sequence program SP shown in FIG. 14 is shown in mnemonic form, and the bit operation operation by the bit operation register PF when executing this sequence program SP is shown.
"A + B" saved in the stack by the execution of the contact input instruction of "000002" is used when the "AND LD" instruction is executed. On the other hand, "LD 0000"
The execution result "X" of the instruction before being saved in the stack by the execution of the contact input instruction "00" remains in the stack S1.

Therefore, in the case of a contact input command such as "LD 000000", it is not necessary to save the PF value in the stack, and wasteful processing is performed. When we actually analyzed the sample sequence program, about 8
The result is that the saving of the PF value is not necessary for about 0% of the contact input commands, and this useless processing is one of the causes that hinder the high-speed processing of the sequence program.

Therefore, the present invention has been made in view of such a problem, and an object thereof is to provide a programmable controller capable of executing a sequence program including a contact input instruction such as an LD instruction at high speed.

[0009]

In order to achieve the above object, in the invention according to claim 1, a programmable controller for executing a sequence program including an instruction such as a contact input instruction is executed by executing each instruction in the sequence program. Regarding the operation register that holds the operation result, the stack that saves the operation result of the instruction executed before the contact input instruction is executed, and the contact input instruction in the sequence program Save information adding means for determining whether or not it is necessary to save the operation result held in the operation register to the stack and adding save information to each contact input instruction indicating whether or not to perform the save; In the case of a contact input instruction that does not need to save the calculation result, refer to the save information added to the contact input instruction by the save information adding means. In is characterized by comprising an instruction execution means for setting the contact input information to the calculation register operation result held in the arithmetic register without retracting into the stack.

According to a second aspect of the present invention, in the programmable controller according to the first aspect, when the instruction executing means sequentially executes each instruction in the sequence program by an interpreter method and executes the contact input instruction, the save is executed. By referring to the save information added to the contact input instruction by the information adding means, only in the case of the contact input instruction that does not need to save the operation result, the operation result held in the operation register is not saved in the stack and the operation register is saved. The contact input information is set to.

According to a third aspect of the present invention, in the programmable controller according to the first aspect, when the instruction executing means expands the sequence program into instructions by a compile method and then executes the instruction to execute the contact input instruction, By referring to the save information added to the contact input instruction by the save information adding means, only in the case of the contact input instruction that does not need to save the operation result, the operation result held in the operation register is not saved in the stack and the operation is performed. It is characterized in that it is executed after being expanded into an instruction for setting contact input information in a register.

According to a fourth aspect of the present invention, in the programmable controller according to the first aspect, the save information adding means analyzes the sequence program from the end to the beginning and refers to the operation result saved in the stack. In the case of a reference instruction, the counter value is incremented, while in the case of a contact input instruction, it is further judged whether or not the counter value has increased from its initial value. While saving information indicating the saving of the operation result is added to the contact input instruction and decrementing the value of the counter, when not increasing, save information indicating that the operation result is not saved is added to the contact input instruction. , Is characterized.

[0013]

According to the present invention, for each contact input instruction in the sequence program, it is judged whether or not it is necessary to save the operation result held in the operation register to the stack when the instruction is executed, Save the operation result held in the operation register to the stack only when executing the contact input instruction that does not need to save the operation result by adding save information indicating whether or not to perform the save to each contact input instruction By setting contact input information in the operation register, the sequence program can be processed at high speed.

[0014]

Embodiments of the PLC according to the present invention will be described below.

FIG. 1 shows the configuration of a first embodiment of a PLC according to the present invention.

This PLC is of an interpreter type in which the instructions in the sequence program are sequentially decoded and executed by an interpreter program, and includes an MPU 11, a save information addition program memory 12, an interpreter program memory 13, an I / O memory 14. It has a sequence program memory 15, a work memory 16, and a programming tool I / F 17.

The save information addition program memory 12 has M
A save information addition program for the PU 11 to operate as a save information addition means is stored, and an interpreter program memory 13 stores an interpreter program for the MPU 11 to execute a sequence program in an interpreter system as an instruction execution means. . The I / O memory 14 stores contact input information to be calculated, the sequence program memory 15 stores a sequence program, and the work memory 16 is provided with a stack counter described later.

FIG. 2 shows an example of the instruction code format of the LD instruction.

This LD instruction indicates the LD instruction with 4 bits of Nos. 9 to 12 of the first (1st) word, and N
A PUSH field is provided in 1 bit of o4, and save information is set. Then, the channel number and contact number of the data to be loaded are set in the second (2nd) word. In the LD instruction immediately after being read via the programming tool I / F 17, the value of this PUSH field is indefinite, and it is judged whether or not the PF value needs to be saved by the save information addition process described later, and the save information is saved. Is set.

FIG. 3 shows P in the MPU 11 according to the present invention.
The F value and the stack configuration are shown. In the present invention, the MPU 11
In the other general-purpose registers R1 and R2, an arithmetic register PF and a stack Sn are provided.

Next, the operation of this embodiment will be described with reference to the drawings.

FIG. 4 shows instruction execution processing by the PLC according to this embodiment.

In this PLC, after the power is turned on, first, a predetermined initialization process is performed (step 100), then a sequence program is read by a programming tool or the like via the programming tool I / F 17 (step 110), and then, Saving information addition program Based on the saving information addition program stored in the memory 12, the saving information addition processing of the instruction, that is, the instruction code of each instruction constituting the sequence program is analyzed, and the PF value is saved only for each contact input instruction. It is determined whether or not it is necessary to add the save information to each contact input command (step 120). This save information addition processing will be described later.

When the save information adding process is completed, the MPU 11 executes an instruction by the interpreter program stored in the interpreter program memory 13 (step 130). At the time of this execution, in the case of a contact input instruction such as an LD instruction, the value of the PUSH field is "1" by referring to the value of the PUSH field of the instruction code format of the contact input instruction as shown in FIG. In this case, the PF value is saved, while when the value of the PUSH field is "0", the PF value is not saved.

Then, the execution processing of such an instruction is repeated until the end (END) instruction is executed, and when the end instruction is executed (step 140 "Yes"), the input / output refresh processing is executed (step 150). When the sequence program is further executed, the interpreter executes the instruction execution process (step 130) again.

Next, the save information adding process for the instructions in the above sequence program will be described.

FIG. 5 shows the procedure of this save information addition processing.

This save information addition processing is performed by "AND L
Paying attention to the fact that stack reference instructions such as "D" and "OR LD" instructions always appear after contact input instructions such as "LD" and "LD NOT" instructions, the stack counter provided in the work memory 16 is It is performed by tracing back from the end of the sequence program in the direction of the beginning of the sequence program to find the difference between the PF value save count and the stack reference count.

That is, first, "0" is set as the initial value of the stack counter, and the instructions in the sequence program are viewed from the end toward the beginning (step 21).
0), and a stack reference instruction such as an "AND LD" instruction (step 220 "Yes"), the value of the stack counter is incremented by 1 (step 230),
Not a stack reference instruction (step 220 “No”),
In the case of contact input command such as "LD" command (step 2
40 "Yes"), then the stack counter value is "0"
It is determined whether or not it is larger (step 250).

Here, if the value of the stack counter is larger than "0" (step 250 "Yes"), it means that the PF value save count is smaller than the stack reference count. Therefore, the PUSH field ( 2 (see FIG. 2) is set to "1" indicating that the PF value is saved (step 26).
0), the value of the stack counter is decremented by 1 (step 270).

On the other hand, when the value of the stack counter is "0" (step 250 "No"), the PF value save count is the same as the stack reference count and the PF value is executed when this contact input instruction is executed. Since it indicates that the saving of the PF value is unnecessary, "0" indicating that the PF value is not saved is set in the PUSH field of the instruction (step 280).

Then, such steps 220 to 280
The above process is repeated until the beginning of the sequence program (step 290 “No”), and when the beginning of the sequence program is reached (step 290 “Yes”),
The evacuation information addition processing of this instruction is ended. By such processing, it is possible to set whether or not to save the PF value for all contact input instructions in the sequence program.

Therefore, for example, when the sequence program SP of the mnemonic expression shown in FIG. 16 described in the conventional example is analyzed by the save information adding process shown in FIG. 5, the contact input command of "LD 000002" appears. In this case, since the “AND LD” instruction appears before that instruction and the stack counter value “1” is set in step 230, it is determined in step 250 that the value is greater than “0”. Step 260
Then, the PUSH field is set to "1", that is, the PF value needs to be saved.

On the other hand, in the case of the contact input command of "LD 000000", the value of the stack counter is decremented by 1 and set to "0" at step 270 when "LD 000002" is analyzed. The value of the stack counter is determined to be "0" in the determination processing of 250, and "1" is set as the save information in the PUSH field in step 260, that is, the PF value need not be saved.

Next, in the instruction execution processing by the interpreter in step 130 of FIG. 4, the contact input instruction execution processing will be described.

FIG. 6 shows the processing procedure of the contact input command.

In this embodiment, the instruction for saving the PF value and the instruction for not saving the PF value are executed in different routines.
In the case of executing the contact input instruction for saving the PF value, as shown in FIG. 7A, the stack saving process of the PF value shown in FIG. 7 is performed (step 310), and then the arithmetic register PF shown in FIG. A contact information setting process is performed (step 320).

On the other hand, in the case of executing a contact input command which does not save the PF value, as shown in FIG.
The stack saving process of the value of the PF value shown in is not performed, but the process of setting the contact information in the arithmetic register PF shown in FIG. 8 is performed (step 330).

FIG. 7 shows the procedure of the above-mentioned PF value saving processing.

In this saving process, as shown in FIG. 3, first, the register R2 provided with the stack Sn is shifted to the left by one bit (step 410), and then the arithmetic register P is set.
In the register R1 provided with F, all but the PF bit are masked to 0 (step 420), and the arithmetic register PF
Side register R1 and the stack Sn side register R2 are ORed to set the PF value in the stack S1 (step 430). It should be noted that each one step substantially corresponds to one step of the MPU instruction.

FIG. 8 shows the procedure of the process of setting the contact input information to the arithmetic register PF described above.

In this process, first, the channel data is read from the I / O memory and set in the temporary register (step 510), and then the temporary register is shifted until the contact input information to be taken out is at the PF value position. , PF value register (step 52)
The process is completed in two steps of 0). Even in this process, each step corresponds to one step of the MPU instruction.

Here, FIG. 9 shows an arithmetic operation in the arithmetic register PF when the same sequence program SP as in the case of the conventional technique shown in FIG. 16 is executed.

As shown in FIG. 9, "LD 00000
In the case of a 0 "contact input command, PUSH is used as described above.
Since "0" is set in the field, indicating that it is not necessary to save the PF value, "X" stored in the PF value by the previous instruction is not saved to the stack S1 when the relevant instruction is executed. .

Further, in the case of the contact input command of "LD 000002", "1" is set in the PUSH field as described above, indicating that it is necessary to save the PF value, so the command is executed. When the previous instruction "O
"A +" stored in the PF value by R000001 "
B "is saved to the stack S1.

Therefore, in the case of a contact input instruction for saving the PF value, as shown in FIG. 6A, the PF value saving process shown in FIG. 7 and the contact information to the operation register PF shown in FIG. In the case of a contact input command that performs both of the set processing but does not save the PF value, as shown in FIG. 6B, the PF value saving processing shown in FIG. Only the setting process of the contact information to the operation register PF shown is performed.

Therefore, when the contact input command that does not save the PF value is executed, useless save processing of the PF value is not executed, and the processing time is reduced by 60% corresponding to 3 steps. become.

When the sample sequence program was actually analyzed, it was found that about 80% of the contact input commands did not require saving of the PF value.

Therefore, in the actual sample sequence program, the processing time is reduced by 60% in step ratio for about 80% of the contact input commands. Therefore, according to the present embodiment, the sequence program can be processed at high speed. I understand.

Next, a second embodiment of the present invention will be described.

Unlike the first embodiment in which the sequence program is executed in the interpreter system, this PLC executes the sequence program in the compiler system.

FIG. 10 shows the configuration of the PLC of the second embodiment.

In the second embodiment, the MPU 21, save information addition program memory 22, compiler program memory 23, I / O memory 24, sequence program memory 25, MPU instruction memory 26, work memory 27, and programming tool I / F 28 are used. The difference from the first embodiment is that the compiler program memory 2 is used instead of the interpreter program memory.
3 is provided and an MPU instruction memory 26 for compiling the sequence program is provided.

Next, the operation of the second embodiment will be described.

FIG. 11 shows the operation of the PLC of the second embodiment.

In the PLC of the second embodiment, after the power is turned on, first, a predetermined initialization process is performed (step 600), and then the sequence program is read from the programming tool via the programming tool I / F 28 (step 600). 610), and subsequently, based on the save information adding program stored in the save information adding program memory 12, the save information adding process of the instruction is performed as shown in FIG. Save information is added to the instruction (step 620).

When the save information adding process is completed, the MPU 21 expands the instruction code to which the save information is added by the compiler program stored in the compiler program memory 23 into an MPU instruction and stores it in the MPU instruction memory 26. (Step 630), the instruction is MPU
21 executes (step 640), and after the execution, I / O refresh processing is performed (step 650).

When a contact input instruction such as an LD instruction is expanded into an instruction by the compiler program in step 630, it is expanded based on the save information set in the PUSH field of the contact input instruction as shown in FIG. To do so.

That is, when "1" is set as the save information, it indicates that the PF value is saved. Therefore, the instruction is expanded to save the PF value, that is, the first embodiment. The instruction is expanded to the instruction that performs both the PF value saving process shown in FIG. 7 and the contact information setting process to the PF value shown in FIG.

On the other hand, when "0" is set as the save information, it indicates that the PF value is not saved, so that the PF value save process shown in FIG. 7 is not executed. The instruction shown in FIG. 8 is developed so that only the contact information is set to the PF value.

Therefore, step 640 in FIG.
Therefore, when the instruction of the contact input instruction which does not save the PF value is executed, the processing time is reduced by 60% corresponding to three steps as in the case of the first embodiment.

Therefore, according to the second embodiment of the compiling method, similarly to the first embodiment, the wasteful PF value saving processing is not executed and the sequence program can be processed at high speed.

[0063]

As described above, according to the present invention, for each contact input instruction in the sequence program, it is determined whether the operation result held in the operation register at the time of executing the instruction needs to be saved in the stack. Only when a judgment is made and a contact input instruction that does not require saving the operation result is executed, the contact input information is set in that operation register without saving the operation result held in the operation register to the stack. It is possible to process the sequence program at high speed without executing the saving process of the PF value.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a first embodiment of a PLC according to the present invention.

FIG. 2 is an explanatory diagram showing an example of an instruction code format of a load instruction.

FIG. 3 is an explanatory diagram showing a PF value and a stack configuration according to the present invention.

FIG. 4 is a flowchart showing the operation of the first embodiment.

FIG. 5 is a flowchart showing a save information addition process for each contact input command.

FIG. 6 is a flowchart showing a processing procedure of a contact input command.

FIG. 7 is a flowchart showing a procedure of PF value saving processing.

FIG. 8 is a flowchart showing a procedure of a process of setting contact information to a PF value.

9 is an explanatory diagram showing a calculation operation for a PF value when the same sequence program as that of the conventional case shown in FIG. 16 is executed.

FIG. 10 is a block diagram showing the configuration of a second embodiment of the PLC according to the present invention.

FIG. 11 is a flowchart showing the operation of the second embodiment.

FIG. 12 is an explanatory diagram showing a configuration of a PF value and a stack in a conventional PLC.

FIG. 13 is a flowchart showing a processing procedure of a contact input command in a conventional PLC.

FIG. 14 is an explanatory diagram showing an example of a sequence program represented by a ladder chart.

FIG. 15 is an explanatory diagram showing a state in the I / O memory.

FIG. 16 is a flowchart showing a bit calculation operation of a PF value in a conventional PLC.

[Explanation of symbols]

 11 MPU (save information adding means, instruction executing means) 12 save information adding program memory 13 interpreter program memory 14 I / O memory 15 sequence program memory 16 work memory 17 programming tool I / F SP sequence program PF operation register Sn (n = 1,2, ...) Stack

Claims (4)

[Claims] 1. In a programmable controller that executes a sequence program including instructions such as contact input instructions, an operation register that holds an operation result obtained by executing each instruction in the sequence program, and before executing the contact input instruction. The stack in which the operation result of the executed instruction is saved and whether or not it is necessary to save the operation result held in the above operation register to the stack for each contact input instruction in the sequence program when the instruction is executed By referring to the evacuation information adding means for adding evacuation information indicating whether or not to perform evacuation to each contact input instruction, and the evacuation information added to the contact input instruction by the evacuation information adding means, In the case of contact input instructions that do not need to save the calculation result, the calculation result held in the above calculation register is transferred to the above stack. Programmable controller characterized by comprising an instruction execution means for setting the contact input information to the calculation register without avoid the. 2. When the instruction executing means sequentially executes each instruction in the sequence program by an interpreter method and executes the contact input instruction, the save information adding means refers to the save information added to the contact input instruction. The contact input information is set in the operation register without saving the operation result held in the operation register to the stack only when the contact input instruction does not require saving the operation result. 1. The programmable controller according to 1. 3. When the instruction executing means expands the sequence program into instructions by a compiling method and then executes the instruction to execute the contact input instruction, the save information added means saves the save information added to the contact input instruction. Refer only to the case of contact input instruction that does not need to save the operation result, expand the operation result held in the operation register to the instruction that sets the contact input information in the operation register without saving to the stack, and execute it The programmable controller according to claim 1, wherein: 4. The save information adding means analyzes the sequence program from the end to the beginning and increments the value of the counter in the case of a stack reference instruction that refers to the operation result saved in the stack, while making a contact. In the case of an input command, it is further determined whether or not the value of the counter has increased from its initial value, and if it has increased, save information indicating save of the operation result is added to the contact input command. At the same time, while decrementing the value of the counter, save information indicating that the operation result is not saved is added to the contact input command when the value has not increased, and the programmable controller according to claim 1.