JP2846760B2 - Programmable controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller used for controlling a plant and the like, and more particularly to a technique for changing the contents of a program executed by the programmable controller.

[0002]

2. Description of the Related Art Conventionally, a change of a control program executed by a programmable controller to control a plant or the like is performed by temporarily stopping the execution of the control program.
In the meantime, it has been common to rewrite the control program stored in the memory of the programmable controller.

FIG. 25 shows a procedure for changing a control program of a conventional programmable controller.

That is, first, the state is monitored (step 251), and when there is an abnormality in the operation of the control program or when the control program needs to be corrected (step 25).
2) Stop the execution of the control program by stopping the address (step 253).

After that, an abnormal control program is detected (step 255), and the control program is read out and corrected by writing, inserting, changing, deleting or the like (step 256). After the correction is completed, the grammar and the like of the control program are checked using a program check function or the like (Step 257), and the control program is started (Step 258). According to FIG. 26, while the operator stops the execution of the control program and rewrites the contents of the memory and starts the control program again as shown in FIG. 26, the execution of the control program is stopped for the rewriting time of the memory contents. I had to let it.

[0006]

By the way, in recent years, the control target of the programmable controller has been diversified, and the number of control objects per day has been increasing.
Some control objects need to be controlled continuously for four hours.

However, according to the prior art, as described above, when the control program of the programmable controller is changed, the execution of the control program must be temporarily stopped.

Accordingly, an object of the present invention is to provide a programmable controller capable of changing a control program for controlling a plant or the like without stopping execution of the program.

[0009]

To achieve the above object,
The present invention provides a method for storing a program in a program area on a memory,
A first step of executing a program to be executed and controlling a control object by copying a program to be changed on the program area to a work area on the same or different memory as the memory; In parallel with the execution of the program stored in the program area, the contents of the program copied in the work area are changed on the work area.
And a third step of switching a program to be executed from the program to be changed to the program stored in the work area.

The method further includes a fourth step of copying the program in the work area to the program area, and a step of executing the program copied from the work area to the program copied in the program area. Fifth program switching
It is desirable to include the following steps.

Further, the second and fourth steps are executed in parallel with the execution of a program stored in a work area to be executed or a program other than the program to be changed in the program area. It is desirable.

[0012]

According to the program changing method of the programmable controller according to the present invention, the program to be changed on the program area is copied to a work area on the same or different memory as the memory, and the program stored in the program area is executed. At the same time, the content of the program is changed on the work area, and after the change is completed, the program to be executed is switched from the change target program to the program stored in the work area.

Accordingly, the program execution means can continue control of the plant or the like using the program before the change in the program area, even while performing a change operation such as a correction or rewriting of the program.

The program in the work area is copied to a program area, and a program to be executed is switched from a program stored in the work area to a program copied to the program area, thereby initializing the programmable controller. You can return to the state.

If the second and fourth steps are executed in parallel with the execution of the program to be executed, the program can be copied during the second and fourth steps. Control of the plant can be continued.

[0016]

An embodiment of the programmable controller according to the present invention will be described below.

FIG. 1 shows the configuration of a programmable controller according to this embodiment.

As shown in the figure, the programmable controller 1 has a central processing unit (hereinafter, referred to as “CPU”).
2, a memory (hereinafter referred to as “MEM”) 3, a direct memory access controller (hereinafter referred to as “DMAC”) 4, a man-machine system base (hereinafter referred to as “MCSI”).
/ F) 5 and a process input / output interface (hereinafter, referred to as “PIOI / F”) 6, which is connected to a plant 8 via a process input / output (hereinafter, referred to as “PIO”) 7. I have. MEM3 is the program area A
And a program area B.

Next, FIG. 2 shows a configuration of software executed by the programmable controller according to the present embodiment.

In the figure, an operating system (hereinafter referred to as an operating system)
The “OS” 200 is a multitasking operating system that manages programs, selects the next program to be started, and starts and restarts the program after interruption.

Each of the programs 1 to m is a program for performing a specific process, and is activated by the OS 200 to perform the process. Among them, programs 1 to n are system programs, which are programs for performing processing such as activation of the DMAC 4 and communication with the MCSI / F 5. On the other hand, programs n + 1 to m are user programs, which are programs for controlling the plant 8. Each program 1-m,
Normally stored in the program area A of the MEM3,
U2 executes the program on the program area A.

A task control block (hereinafter "T
Reference numeral 201) is a table for recording the head addresses and capacities of the programs 1 to m. When starting the program, the OS 200 sets this T
The program is started with reference to the CB.

The last instruction of each of the programs 1 to m is E
If it is ND and END is issued, the OS 200 is started. Further, the OS 200 is also activated by another program activation request instruction, a timer interrupt, and a process interruption request instruction from the plant 8 in each program.

Here, FIG. 3 shows an example of how the user programs n + 1 to m are executed in the programmable controller 1.

FIG. 3 shows a program n + 2, a program n + 3, and a program n + 4 during the execution of the program n + 1.
Are activated, and after the END instruction, the program n +
Returning to 1 shows the processing.

In FIG. 3, a program n + 1 is a base program, which controls the plant 8 consistently from the beginning of the program n + 1 to the program n + 1END, and re-executes processing from the beginning after the end.

The program n + 2 is a program that is called by a program n + 2 start request in the program n + 1 and executes the processing. Program n + 2 is
The processing is terminated by the program n + 2 END instruction.

The program n + 3 is a program that is started by a timer interrupt using a timer pulse generated periodically or at a time as an interrupt. Program n + 3
Ends the processing with the program n + 3 END instruction.

The program n + 4 is a program activated by a process interrupt from the plant 8, and the processing is terminated by a program n + 4 END instruction.

The program n + 1 is a program n
After the +1 END instruction, execution is started again from the head address of the program n + 1.

The switching of the execution of the user program is performed by the OS 200.

FIG. 4 shows a time chart of the program switching by the OS 200.

As shown, the OS 200 starts first. The OS 200 reads the head address of the base program N + 1 from the TCB 201, and starts the program n + 1 from the head.

Thereafter, when a program n + 2 activation request is issued within the program n + 1, the OS is activated as described above. At this time, the address of the next instruction of the program n + 2 activation request is changed to M for restarting the program n + 1.
Record in EM3.

The started OS 200 reads the start address of the program n + 2 from the TCB in response to the request, and starts the program n + 2 from the start. The program n + 2 ends the program n + 2E
Issues an ND instruction and ends.

Accordingly, the OS 200 is started again, and
The restart address of the program n + 1 previously stored in the MEM3 is read from the MEM3, and the program n + 1 is started from the address.

Thereafter, when a timer interrupt occurs, the OS 200 is started again. At this time, the program n +
The address of the instruction to be executed next to 1 is recorded in MEM3. The started OS 200 reads the start address of the program n + 3, which is a timer interrupt processing program, from the TCB, and starts the program n + 3 from the start. After completing the processing, the program n + 3 sets the program n +
Issue 3END instruction and end.

Thus, the OS 200 is started, and the previously stored program n + interrupted by the timer interrupt is started.
1 is read from MEM3 and the program n +
1 is started from the address.

Thereafter, when a process interrupt from the plant 8 occurs, the OS 200 is started. Also at this time, the address of the instruction to be executed next to the program n + 1 is set to MEM.
Record in 3. The started OS 200 reads the start address of the program n + 4, which is the process interrupt processing program, from the TCB 201, and starts the program n + 4 from the start.

After ending the process, the program n + 4 issues a program n + 4 END instruction and ends. As a result, the OS 200 is started, the address stored before the program n + 1 interrupted by the process interrupt is read from the MEM 3, and the program n + 1 is started from the address.

Thereafter, the program n + 1 completes all the processing, and finally issues a program n + 1 END instruction. As a result, the OS 200 starts. OS200
Starts the program n + 1, which is the base program, when there is no other program to be started. At this time, the OS reads the start address of the program n + 1 from the TCB and starts again from the start of the program n + 1.

As described above, from the end or interruption of a program to the start of the next program, the OS 200 is started, and the started OS manages each program. The operating time of the OS is sufficiently shorter than the operating time of the plant control program.

Next, the operation of the DMAC 4 (see FIG. 1) will be described.

DMAC 4 is started by CPU 2 and
M3 data is transferred.

The CPU 2 passes the start address of the transfer source data, the number of data, and the start address of the transfer destination to the DMAC 4 and starts up. When the DMAC 4 starts, the CPU 2
Executes the transfer of the block irrespective of the program being executed, and generates an end interrupt to the CPU 2 after the end.

This transfer operation is performed in data units.
This transfer operation will be described with reference to FIGS.

FIG. 5 shows the CPU 2, DMAC 4, and MEM3.
FIG.

As shown, an STB signal 1 as a memory access timing signal is provided between the CPU 2 and the DMAC 4.
01, and the STB signal 101 includes MEM3
Are connected. Further, the bus request signal 102, the bus use permission signal 103, and the bus use signal 1
04, and a transfer processing end signal 105 and D
A DMAC start signal 110 which is a MAC activation request is connected.

FIG. 6 is a time chart showing the state of each signal after the transfer of the transfer source address, the number of data, and the transfer destination address from the CPU 2 to the DMAC 4. here,
Only one data transfer by the DMAC 4 is shown.

First, the CPU 2 sends the DMAC 4 a D
Issues a MAC start signal 110. This allows DM
AC4 starts and starts memory access, but CPU
When the access overlaps with the access of 2, the signals on the bus interfere with each other and normal operation cannot be performed. Therefore, it is necessary to use the bus alone.

The DMAC 4 issues a bus request signal 102 to the CPU 2 first. When its own memory access is completed, the CPU 2 stops issuing the STB signal 101 and issues the bus use permission signal 103. When the DMAC 4 receives the bus use permission signal 103, the DMAC 4
Issues a bus busy signal 104 other than the CPU. C
The PU2 does not use the bus while other than the own CPU receives the bus busy signal 104, and therefore does not access the memory. In this state, since the DMAC 4 can use the bus independently, the DMAC 4 stops issuing the bus request signal 102. As a result, the CPU stops issuing the bus use permission signal 103.

On the other hand, the DMAC 4 performs memory access and issues the STB signal 101. As a result, when the memory access of one data is completed, the DMAC 4
Stops issuing signal 101, and further issues bus request signal 102,
Other than the CPU stops issuing the bus busy signal 104. This state is received by the CPU 2, and the CPU 2 starts using the bus again. The above procedure is performed for each data access.

As a result, the DMAC 4 performs an operation of reading data from the transfer source data block and writing data to the transfer destination data block, and issues an end interrupt signal 105 to the CPU 2 upon completion of all data. In this way, the DMAC 4 transfers data one step at a time so as not to conflict with the memory access of the CPU 2. That is, in each processing and operation described in the present embodiment, the DMAC 4 executes the transfer in the cycle steal mode.

Next, the operation of the MCSI / F5 will be described.

FIG. 7 shows the configuration around the MCSI / F5.

As shown in the figure, there is an MCSI / F5 connected to the CPU 2 via a bus, and a man-machine system (MCS) 710 for communicating with the MCSI / F5. MCS 710 receives the input from the operator as MCS
The data is transmitted to the I / F 5 and the reception from the MCSI / F 5 is returned to the operator.

The reception register 702 is provided in the MCSI / F5.
And a transmission register 703. The CPU 1 reads and writes these registers via a bus. When receiving an input from the MCS 710, the MCSI / F 5 stores the input in the reception register 707 and outputs a reception interrupt signal 701 to the CPU 2. The content written by the CPU 1 into the transmission register 703 is represented by M
Output to CS710.

FIG. 8 shows the operation timing.

When the operator inputs to the MCS 710,
The MCS 710 sends the input to the MCSI / F5. The MCSI / F5 that has received the input sets the input in the reception register 702 and outputs the reception interrupt signal 701.

When receiving the reception interrupt signal 701, the CPU 2 interrupts the other processing and executes the reception interrupt processing. C
PU2 reads the input in the reception register 702 during the reception interrupt processing.

The CPU 2 sends the response to the MC if necessary.
Write to the transmission register 703 of SI / F5. MCSI
/ F5 converts the response written in the transmission register 703 into M
Send to CS710.

Upon receiving the response, MCS 710 displays the response to the operator.

It should be noted that the MCS 710, M
Inputs sent to CPU 2 via CSI / F5 include:
There are a program name, a program rewriting command, and a program switching command. The format of the program rewrite command is as shown in FIG. 9, and is composed of rewrite data relative step numbers, rewrite data, and a rewrite command.

The CPU 2 processes such an input from the operator by a system program.

The details of the system programs 1 to n (see FIG. 2) will be described below.

The system programs include a reception interrupt processing program, a copy program, a DMAC end interrupt processing program, and a TCB rewriting program.

FIGS. 10 and 11 show the processing procedure of the reception interrupt processing program.

This reception interrupt processing program is executed by MCSI
When a reception interrupt occurs from / F5, the OS 200 is started.

As shown in FIGS. 10 and 11, when this program is started, the input is read from the reception register 702 of the MCSI / F5 (step 1000) and analyzed (step 10019). Execute

(1) In the case of inputting the program name 1010 The program name is passed to the copy program, and the OS 20
Then, a request to start the copy program is issued to 0 (step 1011).

(2) In the case of inputting the number of steps for program rewriting 1030 The input step number data is recorded in the MEM 3 (step 1031).

(3) In case of inputting program rewriting data or rewriting command 1040 The input data is recorded in MEM3 (step 104).
1).

(4) Program rewrite command input 1020 As will be described later, the program transferred to the program area B by the copy program is set as the rewrite target program, and the start address of the program and the MEM3 are recorded first. The rewriting target address is calculated from the program rewriting step number (step 1021), the previously input rewriting data and instruction are read out from the MEM 3 and written to the address (step 1022), and the transmission register 703 Write the rewrite completion response (step 102
3).

(5) In case of program switching command input 1050 As will be described later, the program transferred to the program area B by the copy program is set as a switching target program, and the program name of the program is set to TCB20.
1 Rewriting program (step 1051), OS2
After the base program n + 1 is completed, a request is issued to start the TCB rewriting program (step 1052).

After the above processing, the reception interrupt processing program issues END and ends the processing.

FIG. 12 shows a processing procedure of the copy program.

The copy program is started when a program name is input.

When the copy program is started by the OS 200, the start address and the capacity of the copy target program are read from the TCB 201 from the copy target program name passed from the reception interrupt processing program from the TCB 201 (step 1201), and passed to the DMAC 4, The copy destination address of the program area B is passed (step 120).
2) Turn on the DMAC start signal 101, and
Is started (step 1203).

FIG. 13 shows a processing procedure of the DMAC end interrupt processing program.

This program is started by the OS 200 in response to a copy end interrupt issued from the DMAC 4. The program writes a copy completion response to the transmission register 703 and notifies the operator of the completion of the copy (step 1301).

Next, FIG. 14 shows the processing procedure of the TCB rewriting program.

This program is executed by the OS 200, which has received a start request by the program switching command input processing of the reception interrupt processing program, by the plant 8 control base program n.
It starts when +1 ends. This program determines the start address and the capacity in the TCB of the program which has been transferred to the program area A by the copy program and is the target program to be switched from the start address and the capacity in the program area A to the destination program transferred by the copy program. Rewriting to the start address and capacity of the destination transferred by the copy program in area B (step 140)
1).

The details of each system program have been described above. By the way, the operations performed by these system programs will be collectively described as follows for each input.

First, the operation when a program name is input will be described.

First, when the program name is input from the MCS 710 by the operator, the program name is
The program is transmitted to the SI / F5, the program name is set in the reception register 702, and the reception interrupt signal 701 is turned on.
As a result, in the CPU 2, the reception interrupt processing program is started, the program name is passed to the copy program, and the copy program is started.

Further, the copy program reads the start address and capacity of the program from the TCB, and
4 is passed as the copy source start address and the number of data, and the start address in the program area B, which is the copy destination, is passed.

The DMAC 4 includes a bus request signal 102, a bus use permission signal 103, and a bus busy signal
4 in communication with the CPU 2 and in the cycle steal mode, 1
Transfer step by step. FIG. 15 shows the flow of the program transfer process. When all data copying is completed, the end interrupt 105 is turned on.

As a result, the DMAC end interrupt program is started, and a copy completion response is written to the transmission register 703. The response is sent to MCS 710 and displayed by MCS 710 as a response to the operator.

During the above operation, the CPU 2 continues to execute the program in the program area A,
Do not stop control.

Next, the operation when a program rewrite command is input will be described.

As shown in FIG. 9, the program rewrite command is executed by the MCS 710 in the order of the relative number of steps of the data to be rewritten, the rewrite data or rewrite command, and the rewrite command.
Input from First, the relative step number is MCS710.
Is transmitted to the MCSI / F5, input data is set in the reception register 702, and a reception interrupt is issued. As a result, the reception interrupt processing program is started in the CPU 2, and the input data is recorded in the MEM 3. Next, the rewriting data is also transferred along the same route as MEM3.
Is recorded within.

Next, when a rewrite command is input, the rewrite command is analyzed by the reception interrupt program, and the rewrite target data and the instruction address of the rewrite target program in the program area B are calculated from the relative number of steps. Rewriting data and instructions are written to the rewriting target program, and
A rewrite completion response is output to S710. FIG. 18 shows the flow of this rewriting operation.

In the above operation, the reception of the reception interrupt to the CPU 2 is performed after the CPU 2 waits until the memory access of the CPU 2 is completed, and thereafter, the rewriting is executed for each step. In the above operation, the CPU 2 continues to execute the program in the program area A and does not stop the control of the plant 8.

Next, the operation when a program switching command is input will be described.

[0095] The program switching command is transmitted from the MCS 710.
And is read out to the reception interrupt processing program via the reception register 702 of the MCSI / F5 similarly to the command. As a result, the switching target program name is passed to the TCB rewriting program, and when the base program n + 1 ends, the start address of the switching target program is changed from the start address in the program area A by the TCB rewriting program in the program area B. Rewritten to the start address. FIG. 17 shows the flow of the TCB rewriting process.

During the above operation, the CPU 2
Continues the plant 8 control. Hereinafter, an operation when the program for controlling the plant is additionally modified will be described.

FIG. 18 shows this operation.

In the figure, (a) is the operation of the operator, (b)
Is the DMAC operation, (c) is the state of the CPU, (d) is the ME
(E) shows the contents of the program area B in the MEM.

As shown in the figure, the operator first inputs the name of the program to be rewritten,
As shown in FIG. 15, the AC 4 starts copying one step at a time from the program area A of the MEM 3 to the program area B while checking that the CPU 2 is not accessing the MEM, and responds to the operator after the completion of all copying. At this time, the CPU 2 sets the program area A in the MEM 3
It is operating with the program of.

When a response is returned, the operator checks the MEM3
Rewrite the contents of the memory of the program area B. The DMAC 4 is rewritten by the CPU as shown in FIG.
2 rewrites the memory contents of the MEM3 program area B step by step while checking that the MEM3 is not accessing the MEM3. At this time, the CPU 2
Is in operation by the program in the program area A in the MEM3. After rewriting is completed, the DMAC 4 returns a response to the operator.

After the rewriting is completed, when the operator issues a program switching command, it is determined whether or not the program is END as shown in FIG. 17, and if END, the head address of the task control block is set to the MEM3.
Is rewritten from the address in the program area A to the address in the program area B. As a result, the control program for controlling the plant is switched from the program in the program area A of the MEM 3 to the program in the program area B. As a result, the program can be modified or the program can be changed to the modified program without causing the CPU 2 to stop.

Further, the program rewritten in the program area B of the MEM 3 is copied by the DMAC 4 from the program area B to the program area A one step at a time in the cycle steal mode.
By rewriting the start address of the task control block from the start address in the program area B of the MEM 3 to the start address of the transferred destination program area A by 200, the program executed by the CPU 2 is rewritten from the program area B of the MEM 3 It is possible to return to the area A and return to the initial state.

As a result, the program can be additionally corrected online without affecting the plant control.

Hereinafter, the execution timing of the OS 200 and the program during the operation of FIG. 18 described above will be described.

First, FIG. 19 shows a time chart before and after switching from the program in the program area A to the program in the program area B.

This figure shows a configuration for processing the program m in the base program n + 1, and shows the operation of switching the program m from the program in the program area A to the program in the program area B. I have.

In the figure, the first half is in the middle of program n + 1,
The program m in the program area A is running.
This is because the start address of the program m in the TCB indicates the start address of the program m in the program area A. Then, after the program n + 1 is terminated by END, the TCB rewriting program starts, and
The start address of the program m in the CB is rewritten from the start address of the program m in the program area A to the start address of the program m in the program area B.

Thereafter, the base program n + 1 is started again, and the program m called thereafter is the program m in the program area B. This is TCB
The start address of program m in program area B
This is because the start address of the program m is indicated.

As described above, the program is switched from the program m in the program area A to the program m in the program area B. However, the execution time of the TCB rewriting program is sufficiently shorter than that of the plant control program. Not stopped.

Next, FIG.
4 shows a time chart of a program copy to a program area A.

As shown in FIG. 19, the start address of the program m in the TCB is switched to the program m in the program area B, and the program m in the rewritten program area B is operated. Thereafter, the base program n + 1 When the END instruction is issued, the OS 200
Determines whether the program is normal or abnormal using a normality determination program whose processing procedure is shown in FIG. 21 (FIG. 21, steps 2101 and 2102). If the program is normal and there is no other program to be started, the copy program is Activate (step 2103), and program area B from TCB
Read the start address and capacity of the program
C4, the copy destination address of the program area A is passed, and the DMAC start signal is turned on.
Start C4. Thereafter, the program n + 1 which is the base program is started.

If abnormal, the CPU 2 activates the TCB rewriting program so as to operate with the program before correction (step 2104), and changes the start address of the program m in the TCB to the program m in the program area A. To the start address of

When the transfer of the program in the program area B to the program area A is completed, the OS 2
00 starts the TCB rewriting program and switches the program executed by the CPU 2 from the program area B to the program area A transferred.

FIG. 22 shows a time chart before and after the switching.

In the figure, the first half is in the middle of program n + 1,
The program m in the program area B is operating. This is because the start address of the program m in the TCB indicates the start address of the program m in the program area B. Here, the program n + 1 is EN
After the termination by D, the TCB rewriting program is started, and the head address of the program m in the TCB is rewritten from the head address in the program area B to the head address of the program m in the program area A. After this,
The base program n + 1 is started again, and the program m called thereafter is the program m in the program area A. This is because the start address of the program m in the TCB indicates the start address of the program m in the program area A.

As described above, the program is switched from the program m in the program area B to the program m in the program area A. However, the execution time of the TCB rewriting program is sufficiently shorter than that of the plant control program. Does not stop.

As shown in FIG. 23, the programmable controller 1 according to the present embodiment may be configured by combining the online / offline control circuit 9 and the offline memory 10 with the configuration shown in FIG. .

Thus, the programmable controller 1
With this configuration, a rewritten or changed program can be taken offline and an input / output test can be performed using dummy data in the offline memory 10. That is, the program can be debugged without affecting the plant. As a result, adding programs online,
The reliability at the time of change can be improved.

In the present embodiment, as described above, when the program name is input, the DMAC 4 changes from the program area A in the MEM 3 to the program area B.
Make a program copy to.

This is because, if a procedure as shown in FIG. 24B is used in which a command is first input at the beginning and a program name is input as an operand after that, the rewriting time is long. As shown,
First, enter the program name, and then enter the command (copy, read, write) after that. When the program name is entered regardless of the type of command,
The DMAC 4 copies the program from the program area A in the MEM 3 to the program area B.

In this manner, since the internal processing of the programmable controller 1 and the command input processing of the operator are executed in parallel, as shown in FIG. Can be planned.

On the other hand, a command that does not need to be copied, such as a read command, is also copied. However, as described above, even during the copying, the control of the plant is executed in parallel, so that no problem occurs.

As described above, according to this embodiment, a program can be additionally corrected online without affecting the plant control. Further, since the parallel processing is performed internally, the rewriting time can be reduced, and in particular, the waiting time of the operator can be reduced.

In this embodiment, the DMAC is operated in the cycle still mode. However, for example, in a system that does not require a very high-speed response in controlling the plant, the DMAC is operated in the burst mode. You may.

If the capacities of the program memory and the work memory are equal for each program, the program rewritten on the work memory cannot be returned to the work memory.

[0126]

As described above, according to the present invention, it is possible to provide a programmable controller capable of changing a control program for controlling a plant or the like without stopping execution of the program.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram showing a configuration of software executed by a central processing unit in one embodiment of the present invention.

FIG. 3 is an explanatory diagram showing an execution state of a user program in one embodiment of the present invention.

FIG. 4 is a time chart showing an execution operation of each software in one embodiment of the present invention.

FIG. 5 is a block diagram showing a detailed configuration around a direct memory access controller according to an embodiment of the present invention.

FIG. 6 is a time chart showing a transfer operation of the direct memory access controller according to one embodiment of the present invention.

FIG. 7 is a block diagram illustrating a configuration around a man-machine system interface according to an embodiment of the present invention.

FIG. 8 shows an operator input and C in one embodiment of the present invention.
6 is a time chart showing a relationship between PU operations.

FIG. 9 is an explanatory diagram showing an input format of a program rewriting command according to one embodiment of the present invention.

FIG. 10 is a first half of a flowchart showing a processing procedure of a reception interrupt processing program according to one embodiment of the present invention.

FIG. 11 is a latter half of a flowchart showing a processing procedure of a reception interrupt processing program according to one embodiment of the present invention.

FIG. 12 is a flowchart illustrating a processing procedure of a copy program according to an embodiment of the present invention.

FIG. 13 is a flowchart illustrating a processing procedure of a termination interrupt processing program according to an embodiment of the present invention.

FIG. 14 is a flowchart illustrating a processing procedure of a TCB rewriting program according to an embodiment of the present invention.

FIG. 15 is a flowchart showing a procedure of a program copy operation in one embodiment of the present invention.

FIG. 16 is a flowchart showing a procedure of a memory rewriting operation in one embodiment of the present invention.

FIG. 17 is a flowchart illustrating a procedure of a TCB rewriting operation according to an embodiment of the present invention.

FIG. 18 is a time chart showing a program change operation in one embodiment of the present invention.

FIG. 19 is a flowchart showing a program switching operation in one embodiment of the present invention.

FIG. 20 is a time chart showing a copy operation of a rewritten program in one embodiment of the present invention.

FIG. 21 is a flowchart illustrating a processing procedure of a normality determination program according to an embodiment of the present invention.

FIG. 22 is a time chart showing a program switching operation for returning to an initial state in one embodiment of the present invention.

FIG. 23 is a block diagram showing another configuration of the programmable controller according to one embodiment of the present invention.

FIG. 24 is an explanatory diagram showing an input format of a program copy command according to one embodiment of the present invention.

And FIG. 25 is a flowchart showing a program change processing procedure in a conventional programmable controller.

FIG. 26 is a time chart showing a program change operation in a conventional programmable controller.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Programmable controller 2 Central processing unit (CPU) 3 Memory (MEM) 4 Direct memory access controller (DMA
C) 5 Man-machine system interface (MCSI /
F) 6 Process input / output interface (PIOI / F) 7 Process input / output (PIO) 8 Plant 9 Online / offline control circuit 10 Offline memory

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiromitsu Kikuchi 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture Inside the Omika Plant, Hitachi, Ltd. (72) Ryuichi Watanabe 5-2-2 Omika-cho, Hitachi City, Ibaraki Prefecture 1 Hitachi Process Computer Engineering Co., Ltd. (72) Inventor Takashi Kitada 5-2-1 Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Process Computer Engineering Co., Ltd. (56) References JP-A-4-25904 (JP, A) JP-A-60-229106 (JP, A) JP-A-62-152002 (JP, A) JP-A-59-114602 (JP, A) JP-A-3-28905 (JP, A) JP-A-62-99804 (JP, A) JP-A-62-266604 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G05B 19/05

Claims (1)

(57) [Claims] 1. A program area for storing one or more programs, a work area, a management table for managing a program to be executed, and one or more programs in one or more programs managed as execution targets in the management table. Means for executing a program in accordance with processing, means for copying a program on the program area to a work area, means for changing the program copied on the work area on the work area, instead of the copy source program stored possess a switching means for changing the management contents of the management table to switch the execution target program stored in the work area, said means for copying, the program area Top blog
The program in the work area,
In parallel with the execution of the program, the cycle still mode die
Direct copy by direct memory access transfer
A programmable controller characterized by being a memory access controller.