JPH0330164B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a computer system suitable for performing sequence control and servo control.

(Technical background of the invention and its problems) Conventionally, sequences and servo systems were controlled using a PC.
(Programmable Controller) and CNC
(Computerized Numerical Control), these systems have several drawbacks in programming. In the case of a PC, programming is done using a ladder circuit, so a major drawback is that it cannot be programmed in the way that is done with a general computer. That is, when programming is performed using a ladder circuit, it becomes difficult to program a circuit such as a sequential circuit whose result varies depending on the past state of the circuit. Further, even if such programming can be performed, programming of complex and advanced contents such as computer programming will be even more difficult. In addition, general computers are far more advanced in terms of program development support means and programming techniques, and the inability to utilize these is also a problem.

Furthermore, the speed of control by the PC is limited by the cycle time of the PC, and a quick response of several milliseconds or less cannot be expected. Furthermore, because the number of input/output points on a PC is limited, it is often impossible to input/output numerical data. Furthermore, the PC
In many cases, it was difficult to control sequences and servo systems directly with a PC, as it was difficult to determine conditions that included arithmetic operations.

On the other hand, in the case of CNC, since a computer is used, not only the hardware but also the software of the device is complicated. Therefore, it is difficult for mechanical engineers or on-site personnel with little knowledge of software to create programs or change sequences. To avoid the difficulties of using such system languages,
Although there are systems that have macro languages dedicated to sequences, conventional macro languages are interpreted, resulting in slow execution speed and limited functionality.

(Object of the Invention) The present invention has been made in consideration of the above points, and an object thereof is to provide a program language for sequence control and servo control, and a computer system for executing the program language.

(Summary of the Invention) This invention relates to a computer system suitable for performing sequence control and servo control, and includes a programming language that has three types of parallel processing instructions: an open instruction, a close instruction, and a pause instruction. By providing a computer that does this, it is possible to perform sequence control and servo control easily and efficiently.

(Embodiment of the Invention) In the present invention, a system language is not used as a programming language for sequence control or servo control, but a language such as Basic or Fortran, which can be used even with little knowledge of device software, is used. Of course, the system language can also be used if necessary.

When such a language is used, there is a problem in programming because the operation of the machine sequence is slow compared to the operation speed of the computer. That is, the program will have a lot of waiting time, and during the waiting time the computer will run a loop, and the system will be idle during that time. Also. In order to accurately generate wait times, many flags and timers are required, making the program unnecessarily complex.

Programming using parallel processing to solve these problems can be done in system languages, but not in languages such as Basic and Fortran. The present invention makes this possible by introducing three types of parallel processing instructions: an open instruction, a close instruction, and a pause instruction.

The operation of the open command OPENβ is shown in a flowchart in FIG. The open command OPENβ starts execution of a different program β from the currently executed program α. After this instruction is executed, programs α and β are simultaneously processed in parallel. In sequence control, several sequences are executed in parallel at the same time, and in such cases this instruction is used to perform parallel processing.

The operation of the close command CLOSEβ is shown in Figures 2 and 3.
As shown in the figure. The close instruction CLOSEβ is an instruction for forcibly terminating the program β currently being executed in parallel with the programming α currently being executed. When this instruction is executed, the execution of the program β is forcibly terminated with the instruction being executed. Here, if there are multiple tasks executing the same program, for example, if several programs β are being processed in parallel, the execution of all programs β will be forcibly terminated. By using this close command CLOSEβ, monitoring of processing completion conditions and the like and termination of processing can be performed by a separate dedicated program. You can also use this close command to terminate your own program.

FIG. 4 shows the operation of the pause command PAUSE t.
When this instruction is executed, the execution of the program is interrupted for the time (in milliseconds) given by the parameter t, and then the next process is resumed. For example, if the parameter t is “35”, the processing γ
is executed, the service of the program α is interrupted for 35 milliseconds, and then the service of the program α is restarted and the process δ is executed. While the pause command is being executed, the processing of other programs continues to be executed without being interrupted. This pause instruction PAUSE
t creates timing for waiting for the completion of machine operations and input/outputs without the need for special timers. Also, unlike the case where a loop is used to wait for timing, processing of other sequences is not made to wait during the interruption.

Using the three types of parallel processing instructions, the open instruction, the close instruction, and the pause instruction, as described above,
The fifth method explains how to perform sequence control and servo control.
This will be explained with reference to the example shown in the figure.

The subprogram ALARM shown in the flowchart of FIG. 5 is a program that constantly monitors the error flag in the program SERVO and outputs a message when an error occurs in the program. When an error occurs in the main program SERVO, the value of the element in the array ERROR is set to "1" depending on the type of error. The error message that should be displayed for each element in the array ERROR is
Store it in the corresponding element in the array TABLE in advance. This program ALARM is started using the open command OPEN ALARM in the main program and is executed in parallel with the program SERVO. When started, variable R1 is first set to “0”
(step S1), and set the elements of the array ERROR to
Check whether ERROR (R1) is set to "1" (step S2). If it is not set to "1", the variable R1 is incremented by R1=R1+1 in order to check the next element of the array ERROR (step S3), and the same operation is repeated. In this way, when all the elements of the 65 array ERROR are not "1", it means that no error has been found, so the pause command PAUSE50
After waiting 50 milliseconds (step S5), repeat the same program again.

On the other hand, when it is detected that ERROR (R1) is set to "1" in the conditional branch instruction ERROR (R1) = 1, MESSAGE = TABLE
(R1), the message in the array TABLE corresponding to the element that is "1" in the array ERROR is assigned to the variable MESSAGE (step S2,
S6). Then, the display program is started by the open command OPEN DISPLAY (step
S7), the message stored in the variable MESSAGE is displayed. Also, the program that caused the error
SERVO is forcibly terminated by the close command CLOGE SERVO (step S8). Parallel processing programs using such open, close, and pause commands can check for errors every 50 milliseconds, display errors, and forcibly terminate the program that caused the error, independently of the program SERVO. Can be done.

Next, an example of a program for controlling the servo system and sequence will be described with reference to FIG.

The program always checks the start signal at 30 millisecond intervals (steps S10 and S11).
If a start signal is detected by this check, the speed of the servo system is commanded to 200 rpm (step S12), and the servo program is executed every 5 milliseconds.
OPEN (steps S13, S14). Then input the stop signal and turn on the limit switch.
Check OFF (steps S15 and S16), and if there is no stop signal and the limit switch is off, repeat the above operation, and if a stop signal is detected or the limit switch is on, set the servo system speed to Orpm. command (step S20).
After that, run the servo program every 5 milliseconds.
OPEN (steps S21, S22) and wait for the power to turn off (step S23).

As mentioned above, sequence control and servo control can be easily performed by adding open commands, close commands, and pause commands to languages such as Basic and Fortran.
Next, a computer system for introducing these parallel processing instructions will be explained with reference to FIG.

A program counter 3 and a program memory 4 are connected to the central processing unit (CPU) 2, and the instruction at the address stored in the program counter 3 in the program memory 4 is retrieved and sent to the central processing unit 2. It is loaded and the process is executed. The timer 1 is a counter that counts the current time, and is connected to the central processing unit 2 so that the current time can be read from the central processing unit 2. The central processing unit 2 also includes an address table 5, a time table 7, and a pointer 6.
is connected, and the time data in the time table 7 and the address data in the address table 5 that correspond to the address stored in the pointer 6 can be read from the central processing unit 2. There is.

A method of executing general instructions and an open instruction, a close instruction, and a pause instruction according to the present invention using a computer system having such a configuration will be described.

In the initial state, the program memory 4 contains:
Programs such as sequence control or servo control to be executed are stored, and the program counter 3
It holds the execution start address of the program. Further, the timer 1 has been reset to "0", the address table 5 and the time table 7 are empty, and the pointer 6 points to the beginning of the address table 5 and the time table 7. The central processing unit 2 repeatedly reads and executes the instruction at the address held by the program counter 3. If the read instruction is a general instruction other than an open instruction, a close instruction, or a pause instruction, the instruction is executed and the program counter 3 is updated in the same way as a normal computer. If the read instruction is an open instruction, first the time table 7 is scanned by the pointer 6 and an empty portion of the table is found. Next, the value of the timer 1 is read by the central processing unit 2 and written to the position in the time table 7 where an empty space is found, and the same position in the address table 5 is used to start the program to be opened. The address is written. Thereafter, the value of the program counter is updated to the address of the instruction following the open instruction, and execution of the next instruction begins.

If the read instruction is a close instruction that terminates the program itself that includes the close instruction, the central processing unit 2 first reads the value of timer 1 and scans the time table 7 using the pointer 6. A value smaller than the value of timer 1 is searched for. If there is no such value, timer 1 is read again and the same operation is repeated. If a value smaller than the value of timer 1 is registered, the contents of address table 5 indicated by pointer 6 at that time are stored in program counter 3.
The contents of the time table 7 and address table 5 indicated by the pointer 6 are deleted,
Execution starts from the instruction indicated by program counter 3. In this way, the original program is terminated and execution is transferred to another program.

If the read instruction is a close instruction other than the above, the address table 5 is scanned by the pointer 6, the program to be closed is deleted, and the contents of the time table 7 at the same position are also deleted. In this way, the program is forcibly terminated by the close instruction.

If the read command is a pause command, first the time table 7 is scanned by the pointer 6 and an empty part of the table is found. Next, the value of the timer 1 is read by the central processing unit 2, added to the pause time, and written in the time table 7 at the position where an empty space is found. Further, the address of the instruction following the pause instruction is also written at the same position in the address table 5. Now that the program has been suspended, look for other programs that can be executed while the program is suspended. First, the value of the timer 1 is read by the central processing unit 2, and the time table 7 is scanned by the pointer 6 to search for a value smaller than the other values of the timer 1. If there is no such value, read timer 1 again,
The same action is repeated. If a value smaller than the value of timer 1 is registered, the contents of address table 5 indicated by pointer 6 at that time are transferred to program counter 3, and the contents of time table 7 and address table 5 indicated by pointer 6 are transferred to program counter 3. The instruction is deleted and execution starts from the instruction indicated by the program counter 3. Even in this case, the original program is suspended and execution is transferred to another program.

In this way, general commands, open commands, close commands and pause commands can be executed by the computer system.

As described above, the open command, close command, and pause command can be executed based on the value of timer 1, but similar operations can be performed by providing a service circuit 9 for each pause command as shown in FIG. It can be executed more efficiently.

A program counter 3 and a program memory 4 are connected to the central processing unit (CPU) 2, and the instruction at the address stored in the program counter 3 in the program memory 4 is retrieved and read into the central processing unit 2. It is now being executed. The interrupt clock 11 is connected to the central processing unit 2.
The central processing unit 2 is connected to the central processing unit 2 and is configured to interrupt the central processing unit 2 at regular intervals. Further, a plurality of service circuits 9 and a pause pointer 71 are connected to the central processing unit 2, and the service circuit 9 indicated by the pause pointer 71 is selected. Each service circuit 9 is composed of an address table 5, a service pointer 61 for referring to its contents, a top pointer 62, and a catalog pointer 63. An argument for selecting the service circuit 9 is added to the open command, close command, and pause command.

A method for executing general commands and the open command, close command, and pause command according to the present invention using the computer system shown in FIG. 8 having such a configuration is as follows.

First, after the central processing unit 2 starts operating, the pause pointer 71 selects the service circuit 9 corresponding to the pause time. The pose pointer 71 is set by the central processing unit 2 so that each service circuit 9 is selected corresponding to a predetermined pose pointer. At this time, the pause time is interrupt clock 11.
It is measured by. At this time, the top pointer 62
The contents of the catalog pointer 63 are moved to the service pointer 61, and the contents of the catalog pointer 63 are moved to the top pointer 62. Then, the address on the address table indicated by the service pointer 61 is moved to the program counter 3, and the instruction on the program memory 4 indicated by the program counter 3 is executed. Thereafter, the contents of the program counter 3 are updated in accordance with the executed instructions, and the service is continued, as in a normal computer.

Next, the operation when the open instruction is executed is as follows.
First, with the added argument of the service circuit 9 shown, the start address of the program to be opened is registered in the address table 5 indicated by the catalog pointer 63. The contents of the catalog pointer 63 are then updated to indicate the next position in the address table 5. When the contents of the service pointer 61 and the catalog pointer 63 reach the end of the address table 5, they are updated to indicate the beginning of the address table 5.

Also, the operation when the close instruction is executed is as follows.
The address table 5 is scanned with the added argument of the service circuit 9 shown, and the program to be closed is deleted.

Finally, the behavior when the pause command is executed is
First, with the added argument of the service circuit 9 shown, the next address of the pause command is registered in the address table 5 indicated by the catalog pointer 63. Then, the contents of the service pointer 61 of the service circuit 9 indicated by the pause pointer 71 are updated to indicate the next position in the next address table 5, and the contents of the service pointer 61 and the top pointer 62 are compared, If they do not match, the process branches to the operation after the operation of the CPU 2 is started. Furthermore, if the two match, the process branches to the start operation described above and waits for the pause pointer 71 to be updated by the central processing unit 2.

As described above, the computer system shown in FIG. 8 can execute general commands, open commands, close commands, and pause commands.

In addition, in the above, the system is realized by dedicated hardware having an address table 5, a pointer 6, a time table 7, etc., but this system is implemented only by a general-purpose computer with a timer 1 and software. It is still possible.

(Effects of the Invention) As described above, according to the present invention, sequence control, servo control, etc. can be easily performed using a language other than a system language such as Basic or Fortran. Furthermore, the flags and timers are greatly reduced, making the program simpler and clearer. If high speed or special calculations are required, a system language such as an assembler can also be used. Further, by implementing the present invention using hardware having a time table and an address table, efficient control can be performed.

[Brief explanation of drawings]

Figure 1 is a flowchart showing the operation of the open command, Figures 2 and 3 are flowcharts showing the operation of the close command, Figure 4 is a flowchart showing the operation of the pause command, and Figures 5 and 6. 7 is a flowchart showing an example of a servo control program using an open command, a close command, and a pause command, respectively, and FIGS. 7 and 8 are block diagrams showing an example of the copier system of the present invention, respectively. 1...Timer, 2...Central processing unit, 3...
...Program counter, 4...Program memory, 5...Address table, 6...Pointer,
7... Time table, 11... Interrupt clock, 61... Service pointer, 62... Top pointer, 63... Catalog pointer, 71...
pause pointer.

Claims (1)

[Claims] 1. A computer system for sequence control or servo control, comprising a program storage means in which a plurality of programs are stored, a timekeeping means, an address storage means in which a start address of the program is stored, and a time value measured by the timekeeping means is stored. an open instruction for registering a program to be executed; a close instruction for forcibly terminating a running program or deregistering the registered program; and a clock value storage means for registering a program to be executed; When executing a pause command for stopping for a certain period of time and the open command, the time value of the time measurement means at the time of execution is stored in the empty area of the time value storage means, and the corresponding value of the address storage means is stored. The start address of the program related to the open instruction is stored in the empty area, and when the close instruction is executed, the start address and clock value of the program related to it are stored at the address if the close instruction is for deregistering the registration. and the clock value storage means, and in the case of a close command for forcibly terminating the program, the start address and clock value of the program being executed are deleted from the address storage means and the clock value storage means, and the relevant clock value storage means is deleted. Searching the time value storage means for a time value smaller than the time value of the time measurement means at the time of execution of the close command, starting execution of a program related to a corresponding start address in the address storage means, and executing the pause command. In this case, the value obtained by adding the pause time related to the pause command to the time value of the clock when the pause command is executed and the address of the command following the pause command are stored in the empty area of the clock value storage means and the address of the command following the pause command, respectively. Store the program in the corresponding empty area of the address storage means, search the time value storage means for a timed value smaller than the timed value at the time of execution, and start executing the program related to the corresponding start address in the address storage means. 1. A computer system suitable for sequence control and servo control, characterized in that it has a control means for performing control so as to perform control so as to perform control.