JP3512989B2 - Programmable controller - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is incorporated in various blunts such as manufacturing plants for steel, paper and the like, chemical plants, electric power plants, water and sewage plants, etc., and controls the operations and states of various controlled objects to optimum states. The present invention relates to a programmable controller, and more particularly to a programmable controller that can easily change and add a program to be executed.

[0002]

2. Description of the Related Art A programmable controller incorporated in each of the above-mentioned plants executes various control processes for a controlled object. The control program that executes each control process is usually composed of a plurality of sequence instructions. Further, the control program is usually configured to execute the program by hardware or a microprogram written with a plurality of microinstructions.

However, if the execution control portion of the control program is entirely composed of hardware, it is impossible to change or add the sequence instruction. Therefore, in recent years, the execution contents of sequence instructions are often stored in a rewritable microprogram memory.

[0004]

When the control operation of the programmable controller is controlled by a microprogram, a microprogram memory in which a microinstruction indicating the actual contents of each sequence instruction in each control program is written is, for example, If it is composed of independent rewritable storage elements such as HDD and RAM,
By rewriting each microinstruction that constitutes each sequence instruction, the specific execution contents of the control program can be freely changed.

However, when this microprogram memory is built in an LSI (Large Scale Integrated Circuit) together with other circuit elements, the contents of the sequence instructions are the same as when the execution of this program is realized from the beginning. Cannot be changed.

In order to reduce the number of parts of the programmable controller as a whole, it is desirable to implement the LSI including the above-mentioned micro program memory. However, if there is a possibility that the specific contents of the sequence command may change, the LSI is implemented. Is impossible.

The present invention has been made in view of the above circumstances, and means for switching between a microinstruction read from a microprogram memory and a microinstruction read from a user program memory before the instruction execution unit of the microinstruction. By providing the above, it is possible to provide a programmable controller that can easily change and add the substantial contents of the program executed by this controller even if the microprogram memory is composed of substantial hardware such as LSI. To aim.

[0008]

In order to solve the above-mentioned object, a programmable controller according to claim 1 stores a micro instruction of a program to be executed.
Ikuro program memory and the input micro instruction
The instruction execution means to be executed and the execution mode of the program are specified.
The execution mode instructing means shown and the execution mode instructed
The microprogram memory or user based on
The micro instruction read from the program memory
Instruction selecting means to be given to the instruction executing means, and a user program
In memory microprogram memory stored program
Write microinstruction of another program different from ram
Execution mode instructing means provided with another program writing means
Is forcibly based on the electric signal input from the outside,
The micro instruction read from the user program memory
It is characterized by instructing an execution mode to be selected.

In the programmable controller configured as described above, when different microinstructions from the respective microinstructions of the program stored in the microprogram memory are executed, the different microinstructions are set in the user program memory and executed. The mode instructing means may give the instruction selecting means an instruction to select the microinstruction read from the user program memory.

As a result, the instruction executing means is provided with, instead of the microinstruction read from the microprogram memory,
The micro instruction read from the user program memory is input. Therefore, instead of the microinstruction stored in the microprogram memory, the microinstruction designated by the operator or the user is executed.

That is, even with other potential members, LS
Even if the microprogram memory is incorporated in I, the microinstruction stored in this microprogram memory can be replaced with a different external microinstruction and executed, and the versatility of this programmable controller can be greatly improved.

[0012]

[0013]

[0014]

With this configuration, when a completely different control program different from the control program preset in the programmable controller is executed, the microinstruction of the completely different control program is written in the user program memory. The operation mode may be forced to be set to a mode in which the microinstruction read from the user program memory is selected by using an electric signal from the outside.

In this case, the program stored in the microprogram memory is not used at all, and another program written in the user program memory is exclusively executed.

Further, in this case, the microprogram memory can be removed if necessary .

[0018]

[0019]

[0020]

[0021]

Further, the programmable controller according to claim 2
In Laura, the micro life of the program to be executed
Micro program memory to store the instructions
Instruction execution means for executing microinstructions and program
Execution mode instructing means for instructing the execution mode and this instruction
Based on the executed execution mode.
Microphone read from memory or user program memory
Instruction selecting means for giving an instruction to the instruction executing means,
User program memory to micro program memory
Additional program micro to remembered program
An additional program writing means for writing instructions
The command indicating means is stored in the user program memory.
Depending on the start of reading the additional program, the user program
The execution module that selects the microinstruction read from the memory.
Command, and add the additional data stored in the user program memory.
Upon completion of reading the additional program,
The execution module that selects the microinstruction read from the memory.
The user program, and the additional program writing means
Writes additional program microinstructions to gram memory
In order to do this, the multiple programs that make up this additional program
The black instruction is already stored in the micro program memory.
The corresponding microinstruction,
Read from micro program memory by subroutine
It is characterized by writing in a formula.

By thus writing the additional program in the user program memory by using the subroutine, the microinstructions already stored in the microprogram memory can be used, so that the resources of the entire programmable controller can be made more effective. Can be utilized.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of the programmable controller of the embodiment. In this programmable controller, with respect to the external bus 1, the sequence operation CPU 2 which is the central part of this programmable controller, the user program memory 3 in which the user's unique control program of the programmable controller is stored, and the built-in plant. Input / output port 4 that takes in process data from various controlled objects such as equipment and sends operation data to various controlled objects
And the operator makes various operation commands and user program memory 3
An operation unit 5 for inputting program data of a sequence command and a micro command that constitutes a control program to be set to is connected.

As shown in FIG. 2, the user program memory 3 stores a plurality of sequence instructions 6 constituting a control program set by a user who is the installer of the plant in which the programmable controller is installed, in the order of execution. ing.

In the user program memory 3, if necessary, as shown in FIG. 3, an extended mode instruction command 7 as microinstruction start information and a normal mode instruction command as microinstruction end information. 8 and a plurality of microinstructions 9 sandwiched between the extended mode instruction command 7 and the normal mode instruction command 89 may be written by the write operation via the operation unit 5 by the operator.

In addition, as shown in FIG. 4, only a plurality of micro-instructions 9 forming one control program may be written in the user program memory 3 as needed.

Further, in the user program memory 3, if necessary, as shown in FIG. 5, in addition to the predetermined number of sequence instructions 6 shown in FIG. In some cases, an additional program including the mode instruction instruction 7, the plurality of micro instructions 9 and the normal mode instruction instruction 8 is written.

In the sequence operation CPU 2 forming the central part of this programmable controller shown in FIG. 1, an address counter 11 for designating addresses of the user program memory 3 and the input / output port 4 to the internal bus 10 and a user program memory. 3, a data input / output circuit 12 for performing input / output processing of various kinds of information with respect to the input / output hoat 4 and the operation unit 5, an internal data buffer 13 for temporarily storing data input / output to / from the input / output port 4, Also, an instruction register 14 for temporarily storing various instructions such as the sequence instruction 6, the extended mode instruction instruction 7, the micro instruction 9, and the normal mode instruction instruction 8 read from the user program memory 3 is connected.

When the micro instruction 9 is input from the user program memory 3, the instruction register 14 sends the input micro instruction 9 to the instruction selecting circuit 17. Further, with respect to the internal bus 10, the instruction register 14
An operation as an instruction executing means for executing the micro instruction selected by the instruction decoder 16 which decodes the extended mode instruction instruction 7 and the normal mode instruction instruction 8 fetched into The circuit 18 is connected.

Further, the instruction decoder 16 sends the address contained in the sequence instruction 6 fetched in the instruction register 14 to the microprogram address counter 21 as an initial address value.

When the microinstruction is input, the arithmetic operation circuit 18 executes the control operation instructed by the microinstruction on the process data input from the control target taken in the internal data register 13 and outputs the operation result. And write the operation data to the internal data register 13.

When the normal mode instruction command 8 decoded from the instruction decoder 16 is input, the execution control circuit 15 sets the operation mode of the operation mode register 19 to the "normal operation mode", and the instruction decoder 16 decodes the operation mode. When the extension mode instruction command 7 is input, the operation mode of the operation mode register 19 is set to the "extension operation mode".

Further, when the operation mode set in the operation mode register 19 is the "normal operation mode", the execution control circuit 15 sends a selection command for the micro program memory 20 to the instruction selection circuit 17 to set the operation mode. When the operation mode set in the register 19 is the "extended operation mode", the instruction register 1 is sent to the instruction selection circuit 17.
The selection command of 4 is transmitted.

Further, when the operation mode set in the operation mode register 19 is the "normal operation mode", the execution control circuit 15 outputs one operation result for the micro instruction from the operation circuit 18, that is, one operation result. A count-up signal is sent to the micro program address counter 21 every time one micro instruction is executed.

When the operation mode set in the operation mode register 19 is the "extended operation mode", the execution control circuit 15 outputs each operation result for the micro instruction 9 from the operation circuit 18, that is, Each time one microinstruction 9 is executed, a count-up signal is sent to the address counter 21.

Micro program address counter 21
Each time the count-up signal is input from the execution control circuit 15, the microprogram memory 20 stores the address value counted up from the previously input initial address value.
Apply to.

In the microprogram memory 20, a plurality of microinstructions for executing each sequence instruction 6 stored in the user program memory 3 are stored. Then, the address in which the leading microinstruction in each sequence instruction 6 is stored, that is, the leading address is designated by each sequence instruction 6.

As a result, the microprogram memory 20
From the sequence instruction 6 stored in the instruction register 14
Each macroinstruction that composes the above is sequentially read and sent to the instruction selection circuit 17.

The instruction selection circuit 17 selects the micro instructions sequentially read from the micro program memory 20 during the period when the execution control circuit 15 applies the selection instruction of the micro program memory 20, and the arithmetic circuit 1
8 is sent.

Further, the instruction selection circuit 17 selects the macro instructions 9 sequentially read from the instruction register 14 to the arithmetic circuit 18 during the period when the selection command of the instruction register 14 is applied from the execution control circuit 15. Send out.

Next, the operation of the programmable controller thus configured will be described. 1) During normal operation In this case, as shown in FIG. 2, the sequence instructions 6 of the control program indicating the control executed by the programmable controller are sequentially stored in the user program memory 3.

In this case, the "normal operation mode" is set in the execution mode register 19. When the operator inputs a start command via the operation unit 5, the start command is taken into the command register 14 via the data input / output circuit 12. Then, the address counter 11 is activated, and the user program memory 3 designated by the address counter 11
The first sequence instruction 6 in the above is read and taken into the instruction register 14.

When the head sequence instruction 6 is fetched into the instruction register 14, this sequence instruction 6 is decoded by the instruction decoder 16 and the operation of the execution control circuit 15 is determined according to the result to constitute the sequence instruction 6. The micro instruction is read from the micro program memory 20 and sent to the arithmetic circuit 18 via the instruction selection circuit 17.

The arithmetic circuit 18 executes predetermined control arithmetic processing on the process data to be controlled, which is read by the internal data register 13, and once writes the arithmetic processing result to the internal data register 13. Internal data register 1
The operation processing result once written in 3 is the data input / output circuit 1
2 via the input / output port 4 as operation data to the control target.

Every time one micro instruction is executed by the arithmetic circuit 18, the execution control circuit 15 sends a count-up signal to the micro program address counter 21 to update the address output to the micro program memory 20.

Therefore, each microinstruction that composes the corresponding sequence instruction 6 stored in the microprogram memory 20 is sequentially read and executed by the arithmetic circuit 18. When the control process for one sequence instruction 6 is completed, the next sequence instruction 6 is read from the user program memory 3, and each microinstruction forming the corresponding sequence instruction 6 is read from the microprogram memory 20 and sequentially executed. .

As described above, during the normal operation, the control program is sequentially executed only by each microinstruction stored in the microprogram memory 20 of the sequence operation CPU 2.

2) When a microinstruction is defective or when a microinstruction is changed Next, a failure occurs in each microinstruction that constitutes each sequence instruction stored in the microprogram memory 20, or a specific microinstruction is changed. In this case, the operator operates the operation unit 5 to replace the sequence instruction to which the corresponding microinstruction in the user program memory 3 belongs, as shown in FIG. The micro instruction 9 and the normal mode instruction instruction 8 are written.

In this case, the "normal operation mode" is set in the execution mode register 19 when the programmable controller is activated. Therefore, since the first sequence instruction 6 to the fourth sequence instruction 6 in the user program memory 3 of FIG. 3 are in the normal operation mode setting, as described above, each stored in the micro program memory 20. Microinstructions are executed in sequence.

When the extended mode instruction instruction 7 is taken into the instruction register 14 instead of the fifth sequence instruction 6, the operation mode of the operation mode register 19 is changed to the "extended operation mode", and the execution control is executed. A selection command from the circuit 15 to the instruction register 14 is applied to the instruction selection circuit 17.

When the address counter 11 designates the microinstruction 9 at the address next to the extended mode instruction instruction 7 in the user program memory 3, the microinstruction 9 passes through the instruction register 14 and the instruction selection circuit 17 and the arithmetic circuit. 18 is input. Therefore, the arithmetic circuit 18 executes the microinstruction 9 read from the user program memory 3.

When the execution of one microinstruction 9 is completed, the execution control circuit 15 sends a count-up signal to the address counter 11, so that the address counter 11 specifies the next microinstruction 9. In this way, each microinstruction 9 in the user program memory 3 is sequentially executed.

When the address counter 11 designates the normal mode instruction command 8, the normal mode instruction command 8 is issued.
Are taken into the instruction register 14. As a result, the operation mode of the operation mode register 19 is changed from the "extended operation mode" to the "normal operation mode". Then, a selection command for the microprogram memory 20 is applied from the execution control circuit 15 to the instruction selection circuit 17.

Therefore, thereafter, each microinstruction read from the microprogram memory 20 is input to the arithmetic circuit 18 via the instruction selection circuit 17. That is, the sixth and subsequent sequence instructions 6 in the user program memory 3 are executed by the respective micro instructions stored in the micro program memory 20.

As described above, the microprogram memory 20 formed by virtual hardware such as an LSI is used.
If a problem occurs in the microinstruction stored in the microinstruction or it is necessary to change a part of the microinstruction, the modified or changed microinstruction 9 is stored in the external user program memory 3 and the extended mode instruction is issued. By inserting and setting between the instruction 7 and the normal mode instruction instruction 8, it is possible to automatically execute the modified or changed microinstruction 9.

3) When executing a completely different control program, a completely different control program is used without using a control program composed of a plurality of microinstructions stored in the microprogram memory 20 in the sequence operation CPU 2. Therefore, it may be necessary to operate this programmable controller.

In this case, the operator, as shown in FIG.
A plurality of microinstructions 9 constituting another control program to be executed are written in the user program memory 3 via the operation unit 5.

Further, an external setting signal which is an electric signal is applied to the execution mode register 19 to forcibly set the operation mode to the "extended operation mode". Therefore, the operation mode of the execution mode register 19 maintains the "extended operation mode" no matter what mode specifying instruction is taken in the instruction register 14. Therefore, the instruction selection circuit 17 always selects each microinstruction 9 fetched from the user program memory 3 into the instruction register 14 and sends it to the arithmetic circuit 18.

When the programmable controller set in this way is activated, an activation instruction is fetched from the operation unit 5 into the instruction register 14 and the address counter 11 is activated and stored in the user program memory 3 shown in FIG. The respective micro-instructions 9 are designated in order. Each microinstruction 9 sequentially designated by the address counter 11 is sequentially input to the arithmetic circuit 18 via the instruction register 14 and the instruction selection circuit 17.

The arithmetic circuit 18 sequentially executes each micro instruction 9 read from the input user program memory 3. Thus, for example, in a small programmable controller, the microprogram memory 2
If you want to omit 0 itself, execute mode register 19
It is possible to forcibly set the operation mode to the "expansion operation mode" by an external setting signal consisting of a fixed electric signal, instead of the software instruction for the expansion mode instruction.

Therefore, it is possible to read each microinstruction 9 from the user program memory 3 from the time when the program controller is started up. Therefore, when there are few kinds of sequence instructions 6 and the circuit of the sequence operation CPU 2 is used. This is effective for applications where you do not want to increase the scale.

4) When an additional program is executed (No. 1) Even if each microinstruction constituting the control program stored in the microprogram memory 20 incorporated in the sequence operation CPU 2 is normal , You may want to run another control program with this programmable controller.

In such a case, as shown in FIG. 5, after the sequence instructions 6 of the control programs 1 to 9 of the control program already written in the user program memory 3, the control program to be added this time is added. The extended mode instruction instruction 7 and the normal mode instruction instruction 8 are arranged before and after each micro instruction 9.
Write with a pinch in between.

As described above, when the programmable controller is started in a state in which each microinstruction 9 of the additional control program is written in the user program memory 3,
After the sequence instructions 6 from the 1st to the 9th are executed, the microinstructions 9 of the control program added this time are executed in the same procedure as when the microinstruction fails or the microinstruction is changed. .

When each microinstruction 9 of this additional control program is written in the head portion of the user program memory 3, after this additional control program is executed,
The control program that has already been set is executed.

As described above, by adjusting the writing position of the additional control program in the user program memory 3, the additional control program can be executed at an arbitrary timing.

In the conventional programmable controller, if there is no problem in the contents of the control program and a new control program is added or the sequence instruction is to be expanded, the sequence operation CPU 2 should be redesigned or the sequence instruction 6 It was necessary to realize the new function by combining.

However, in the programmable controller of this embodiment, the necessary control program and the microinstruction 9 of the necessary sequence instruction 6 are newly written in the user program memory 3 at the timing position to be executed, so that the programmable operation is facilitated. It is possible to extend the functionality of the controller.

5) When executing an additional program (No. 2) In this case, the maker of this programmable controller publishes each micro instruction of the micro program memory 20 and each sequence instruction of the user program memory 3 to the user in advance. Keep it.

When the user of this programmable controller executes an additional control program, the user can freely create a new control program on the user program 3 in the same manner as the above-mentioned new program execution method. At the same time, if there is a sequence command 6 created by the manufacturer and set in the user program memory 3 among the plurality of sequence commands constituting this new control program, each of the sequence commands 6 It is also possible to describe that the micro instruction is called from the micro program memory 20 in a subroutine format.

Since each microinstruction already stored in the microprogram memory 20 in the subroutine format can be used in this manner, it is not necessary to write the microinstruction in the user program memory 3 in duplicate, and the resources of the programmable controller can be saved. It can be used more effectively.

[0073]

As described above, according to the programmable controller of the present invention, the microinstruction read from the microprogram memory and the microinstruction read from the user program memory are provided before the instruction execution unit of the microinstruction. Means for selecting are provided.

Therefore, even if the microprogram memory is composed of substantial hardware such as an LSI, the substantial contents of the program executed by this programmable controller can be easily changed and added.

When the microinstruction stored in the microprogram memory has a defect or when it is desired to change the content of the microinstruction, the execution content of the microinstruction can be easily changed.

Further, by changing the operation mode by an electric signal from the outside, the micro program memory can be deleted by always reading the micro instruction from the external user program memory.

Further, when an additional program is required for the program stored in the microprogram memory, each microinstruction of this additional program is written in the user program memory.

Therefore, the number of programs executed by this programmable controller can be easily increased. Further, by writing the program in the user program memory in the subroutine format, it becomes unnecessary to duplicately write the micro instruction in the user program memory 3, and the resources of the programmable controller can be utilized more effectively.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a programmable controller according to an embodiment of the present invention.

FIG. 2 is a diagram showing stored contents of a user program memory of the programmable controller.

FIG. 3 is a diagram showing the contents stored in a user program memory of the same programmable controller.

FIG. 4 is a diagram showing stored contents of a user program memory of the programmable controller of the same.

FIG. 5 is a diagram showing stored contents of a user program memory of the same programmable controller.

[Explanation of symbols]

1 ... External bus 2 ... Sequence operation CPU 3 ... User program memory 4 ... I / O port 5 ... Operation part 6 ... Sequence command 7 ... Extended mode instruction command 8 ... Normal mode instruction command 9 ... Micro instruction 10 ... Internal bus 11 ... Address counter 12 ... Data input / output circuit 13 ... Internal data register 14 ... Instruction register 15 ... Execution control circuit 16 ... Instruction decoder 17 ... Instruction selection circuit 18 ... Arithmetic circuit 19 ... Execution mode register 20 ... Micro program memory 21 ... Micro program address counter

Claims (2)

(57) [Claims] 1. A microprogram memory for storing microinstructions of a program to be executed, an instruction executing means for executing an input microinstruction, and an execution mode instructing means for instructing an execution mode of the program, which are instructed. and instruction selection means for providing a microinstruction read from the microprogram memory or a user program memory based on the execution mode to said instruction execution unit, said microprogram to said user program memory
Another program different from the program stored in memory
Another program writing means for writing the micro instruction of the
The execution mode instructing means is provided with an electric signal input from the outside.
Read from the user program memory
Indicates the execution mode that selects the issued microinstruction
A programmable controller characterized in that 2. A microinstruction of a program to be executed
Micro program memory for storing, instruction executing means for executing input micro instruction, and execution mode instructing means for instructing execution mode of program
Based on this execution mode specified ,
Read from gram memory or user program memory
Instruction selecting means for giving the micro instruction to the instruction executing means
And the microprogram in the user program memory
Additional program to the program stored in memory
With additional program writing means to write the micro instruction of
The execution mode instructing means is stored in the user program memory.
In response to the start of reading the stored additional program, the user
Selects microinstructions read from the program memory
The execution mode to be executed and write it in the user program memory.
Upon completion of reading the stored additional program, the microphone
(2) Select micro instruction read from program memory
An execution mode to be executed, and the additional program writing means sets the user program
Write micro-instructions for the additional program in memory
The multiple microphones that make up this additional program
B instructions already stored in microprogram memory
The corresponding microinstruction, the corresponding microinstruction is supported.
Format to read from microprogram memory with Bruchin
Programmable controller characterized by writing in
La.