JPS6112564B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a programmable sequence controller, and more particularly to a control system based on a step-by-step command system that can also perform scanning-type processing. The command systems and architectures of programmable sequence controllers are broadly classified into scanning type (also called random logic type) and process step type (also called time chart type). There are scanning types in which programs are created based on contact or non-contact sequence circuit diagrams, and programs are created based on flowcharts, but the basic architecture is that each output terminal is The on/off conditions for each output are expressed in a predetermined command format and stored in the program storage unit, such as turning on the output when the condition is met and turning it off when the condition is not met. When executing,
Instructions related to each output terminal are sequentially and repeatedly read out and executed at high speed. In the step-by-step method, instead of considering output state transitions for each individual output terminal, a certain output state as a whole resulting from a combination of outputs from each output terminal is considered as one process, and output state transitions are considered as one process. Think of it as a sequential change in the process. Then, the output state in each process, the conditions for proceeding from that process to the next process, and process changes such as jumps are expressed in a predetermined command format and stored in the program storage unit. When executing this process, the command for one process is read out, the output status set in that process is output from all output terminals, and the set conditions for proceeding to the next process are constantly checked, and the conditions are checked. As long as the condition is not satisfied, the output state of the process is maintained, and when the condition is satisfied, the process proceeds to the next process. By the way, as mentioned above, the step-by-step type handles the states of all output terminals as one process, so it is suitable for small-scale equipment with a relatively small number of output terminals. The feature is that even people without conventional control knowledge such as sequence circuits can create programs. On the other hand, in the case of the above-mentioned scanning type, experts in conventional sequence circuits based on wiring logic can utilize their expertise to perform complex and sophisticated control. As described above, the stepwise type and the scanning type have different characteristics, and one type of controller is selected depending on the control specifications to be applied and the user. This invention enables a single controller to perform both process step-type and scanning-type processing. Specifically, under the process step-type command system, scanning can be performed by arbitrarily specified commands. The present invention provides a control method that is executed by processing shapes. According to this, the control function of the step-by-step controller is expanded, and it becomes possible to use it in various ways according to the needs of the user. Hereinafter, one embodiment of the present invention will be described in detail based on the drawings. FIG. 1 is a block diagram showing the electrical configuration of a sequence controller according to the present invention, and FIG. 2 shows its external appearance. This sequence controller includes a central processing unit 2 composed of a so-called microcomputer made into firmware,
An input circuit 3 is an input interface between an external contact connected to the input terminal IN and the central processing unit 2.
, an output circuit 4 that controls an external device connected to the output terminal OUT according to an output signal from the central processing unit 2, a program storage section 5 that stores a sequence program arbitrarily set by the user, and a program storage section 5 that stores a sequence program arbitrarily set by the user; A key input device 6 used for
Display 7 that displays the command being set when setting a program, and the command being executed when executing the program.
etc. User commands for each process unit in this sequence controller are configured in the format shown in the table below.

[Table] The instruction code "OP" has 4 bits and represents the type of processing operation. The modification data "DATA-1" and "DATA-2" are each 8 bits (2-digit binary coded decimal code, the modification data as a whole is a 4-digit binary coded decimal code), and the instruction Specify specifically the type of processing operation represented by the code. The output control command ``OUT'' is data having the same number of bits as the number of output terminals in one-to-one correspondence with each output terminal, and in normal step-by-step processing, it indicates whether each output terminal is on or off. Corresponding to this command format, the display 7
As shown in Fig. 2, there is a two-digit numerical display ₇₁ that displays the process number (step number), and a one-digit numerical display ₇₂ that displays the decimal converted instruction code "OP". , a total of 4 digit numerical displays 7 ₃ and 7 ₄ that convert and display the modified data "DATA-1" and "DATA-2" in decimal, and each output terminal.
It is composed of a group of LED lamps ₇₅ , etc., each displaying the output signal status of OUT. Next, general instruction codes and their execution contents in this programmable controller will be briefly explained. (a) "NOP"; Non-operation command Proceeds to the next process number without doing anything. (b) “END”; End command Indicates that one cycle of processing has ended. (c) "JMP"; Jump command Jumps to the process number specified in "DATA-1" and continues execution from there. Also, if the input terminal number is programmed in "DATA-2", the input specified in "DATA-2" will be received, the process will jump to the process number specified in "DATA-1", and the execution will continue from there. . (d) "AND"; AND instruction When the input signals of the two input terminal numbers specified as "DATA-1" and "DATA-2" are aligned, proceed to the next step number. (e) "OR"; OR instruction Receive the input signal that comes first from either of the two input terminal numbers specified as "DATA-1" and "DATA-2" and proceed to the next process number. (f) "CNT"; Count instruction "DATA-1"
The input signal from the input terminal number designated as "-2" is counted, and when the count is up, the process advances to the next process number. (g) "CJP"; Conditional jump command If the input signal of the input terminal number specified in "DATA-2" is on, jumps to the process number specified in "DATA-1", and the above input signal If it is off, proceed to the next process number. (h) “RAT”; Repeat command Repeats the process from the process number specified in “DATA-2” to the current process number up to the number of times specified in “DATA-1”. (i) "TIM"; Timer command When the time specified in "DATA-1" and "DATA-2" has elapsed, proceed to the next process number. The above is a very well-known instruction code,
The signal processing procedures used in this implementation are also well known and will not be described in detail. The controller according to the present invention is based on the well-known command system and processing method as described above,
To this end, a new control method, which will be explained below, has been introduced. In order to embody the control method of the present invention, a scanning start command "SCA" is newly defined as the command code "OP" in addition to the above (correspondingly, the key input device 6 is set to "SCA"). ” key is provided). This scanning start command indicates that the following command is to be scanned, and no modification data is set for this command. In this embodiment, scanning processing can also be performed for the above-mentioned AND instruction and OR instruction, and the above-mentioned conditional jump instruction is used as an instruction for returning from scanning processing to normal process step processing. A specific program will be explained below. In the program in the table below, the number of output terminals is 8 to simplify the explanation.
represents an output control command.

[Table] The instruction with process number 21 is a timer instruction, which turns on the output of terminal numbers 1, 2, 3, and 4, and turns on the output of terminal numbers 5 and 4.
Turn off outputs 6, 7, and 8 Set output status to 10 minutes 30
It continues for a second and then goes to the next step number 22. The instruction with step number 22 is an AND instruction, which turns on the outputs of terminal numbers 2, 3, 4, and 5, and turns off the other outputs. This indicates that the process continues until the AND condition is satisfied, and when the AND condition is satisfied, the process proceeds to the next step number 23. The instruction with process number 23 is an OR instruction, and terminal number 1,
The output state of turning on outputs 3, 5, and 7 and turning off the other outputs continues until the OR condition of the input signals of input terminal numbers 03 and 04 is satisfied, and when the OR condition is satisfied, the next step number 24 It means to proceed to. The instruction with step number 24 is a counter instruction that turns on the outputs of terminal numbers 5, 6, 7, and 8 and turns off the other outputs until the input signal from input terminal number 05 is counted 12 times. Continue for a while, and when the count is completed 12 times (counting conditions are met), proceed to the next step number 25. The command with process number 25 is the above-mentioned scanning start command, and the following process number 26 is an AND command, and the process number is
An OR instruction is set in 27, and a conditional jump instruction is set in step number 28. The contents of this conditional jump instruction are the input terminal number
This indicates that if there is no input signal from terminal number 15, the process jumps to process number 25, and if there is an input signal from terminal number 15, the process proceeds to the next process number 29. The instructions in step numbers 25, 26, 27, and 28 represent scanning of the AND instruction in step number 26 and the OR instruction in step number 27. The AND instruction in process number 26 changes the output state of turning on only the output of terminal number 1 and turning off the other outputs in normal process step processing, using the input terminal number.
This means continuing until the AND condition of input signals 11 and 12 is satisfied, and this is executed in the scanning process as follows. If the AND condition of the input signals of input terminal numbers 11 and 12 is satisfied at the time of execution of the instruction of step number 26, the output of terminal number 1 is turned on (other outputs are not operated, so ), if the AND condition is not satisfied, turn off the output of terminal number 1 (other outputs are not operated), and immediately proceed to the next step number 27 regardless of whether the AND condition is satisfied or not. The OR instruction of process number 27 is the OR condition of the input signals of input terminal numbers 13 and 14, which would turn on terminal numbers 2 and 3 and turn off the other outputs in normal process step processing. This means to continue until the following is established, and this is executed in the scanning process as follows. If the OR condition of the input signals of input terminal numbers 13 and 14 is satisfied at the time of execution of the instruction in step number 26, the outputs of terminal numbers 2 and 3 are turned on (other outputs are not operated), and the OR condition is satisfied. If the OR condition is not satisfied, the outputs of terminal numbers 2 and 3 are turned off (other outputs are not operated), and the process immediately proceeds to the next step number 28 regardless of whether the OR condition is satisfied or not. Therefore, while there is no input signal from input terminal number 15, which is the condition for the conditional jump command of step number 28, the commands of step numbers 25, 26, 27, and 28 are repeated at high speed due to scanning processing. executed. As a result, the output of terminal number 1 is turned on when the AND condition of input terminal numbers 11 and 12 is satisfied, and is turned off when it is not satisfied, and the output of terminal number 2 and 3 is turned on when the OR condition of input terminal numbers 13 and 14 is satisfied. When the count instruction is not established, it is turned on, and when it is not satisfied, it is turned off, and the other outputs remain as they were when the count instruction of process number 24 was executed (the output of terminal number 4 is off, and the output of terminal numbers 5, 6, 7, and 8 is on). There is. This output state continues until the input signal of input terminal number 15 is detected, and when that input signal is detected, step number 29
Let's move on to. The instruction with process number 29 is an AND instruction, and the process step is processed as described above, and the next instruction with process number 30 is a timer instruction, and the process is processed as described above. Next, the signal processing procedure by which the central processing unit 2 implements the above-mentioned instruction execution control will be explained with reference to the flowchart shown in FIG. This flowchart shows the configuration of an operating program stored in the ROM in the output control command 2 formed by a microcomputer. In routine 1, the program storage unit 5 is addressed with the contents of the process counter PC (i.e., the process number) set in the RAM in the central processing unit 2, and the user command (process update command and output control command) for that process number is executed. Read and store in the instruction register set in the RAM. In the next routine 2, the instruction code "OP" in the instruction stored in the instruction register is decoded, and control is distributed according to each instruction code. If the decoded instruction code is a scanning start instruction, proceed to routine 3, set the scanning SF set in the RAM above to "1", and increment the process counter PC (add 1) in the next routine 4.
and return to the first routine 1. If the instruction code is a conditional jump instruction, proceed to routine 5 and set the above scan flag.
Reset SF to "0" and check in the next routine 6 whether or not there is an input signal with the input terminal number specified by the modifier data "DATA-2". If there is that input signal, proceed to routine 4. process counter
The PC is incremented and the process returns to routine 1. If there is no input signal, the process proceeds to routine 7, where the process number designated by the modification data "DATA-1" is preset in the process counter PC, and the process returns to routine 1. If the instruction code is an AND instruction, the process advances to routine 8 and the modification data “DATA-1” and “DATA-
The input signals of the two input terminal numbers specified in "2" are checked, and it is determined whether the AND condition is satisfied or not. If the condition is satisfied, the process goes to routine 9, and if the condition is not satisfied, the process goes to routine 10. move on.
The determination contents of routines 9 and 10 are the same, and it is determined whether the scan flag SF is "1" or not. Depending on the result of this determination, the processing is divided into the above-mentioned process step process or scanning process. The above AND condition is not satisfied, so NO in routine 8.
If it is determined that the scan flag SF is "0" at this time and the determination in routine 10 is NO, the process advances to routine 11 and step-by-step processing is performed. That is, in routine 11, the output of the terminal number set to "1" by the output control command "OUT" is turned on, and the output of the terminal number set to "0" is turned off. After that, the routine returns to routine 2. Therefore, for the AND instruction previously read into the instruction register, routine 2 → 8 is executed again, and if the AND condition is not satisfied, routine 1 is executed again.
The sequence is executed from 0 to 11, and the process returns to routine 2. In other words, while the AND condition is not satisfied, routine 2 → 8 →
Steps 10→11 are repeated, and the output state set in the output control command is maintained. When the above AND condition is satisfied, the routine 8 makes a NO judgment and proceeds to the routine 9, but here, the same as above, it makes a NO judgment and proceeds to the routine 12, where the process counter PC
and returns to routine 1. In other words, the process moves on to execution of the instruction with the next process number. The above is the normal step-by-step processing of the AND instruction. When the OR instruction is decoded in Routine 2, the process proceeds to Routine 18, where the input signals of the two input terminal numbers specified by the qualifying data "DATA-1" and "DATA-2" are checked, and the OR condition is met. If the condition is satisfied, the process goes to routine 9, and if the condition is not satisfied, the process goes to routine 10. As with the AND instruction above, the process progresses depending on the state of the scan flag SF. or scanning processing. The step progression process when SF="0" is the same as that for the AND instruction, so it will not be described in detail. Routine 13 is collectively shown as an execution routine for instructions other than the above-mentioned four types of instructions. This routine 13 includes a timer instruction, a count instruction,
In addition to determining the success or failure of the jump command and repeat command conditions, similarly to routine 11, it turns on the output of the terminal number set to "1" by the output control command, and turns the output of the terminal number set to "0" by the output control command. Perform step-by-step output control to turn off, and as long as the above conditions are not met, return to routine 2 and repeat routines 2→13. When the above conditions are met, proceed to routine 14 to control the process counter. Update the PC and return to Routine 1. This process counter PC
An update is an step that adds 1 to the contents of the PC,
This includes both presetting a specific step number into the PC, such as Routine 7. Next, scanning type processing of AND instructions and OR instructions will be explained. If the scanning flag SF is set to "1" by the scanning start command and the following process number command is an AND command, routine 8
The success or failure of the AND condition is checked, and depending on the success or failure, the state of the scan flag SF is checked in routine 9 or 10. First, if the AND condition is not satisfied, proceed to routine 10.
The determination is YES, and the routine proceeds to routine 15. In this routine 15, the output of the terminal number set to "1" by the output control command is turned off. Thereafter, in routine 12, the process counter PC is incremented and the process returns to routine 1. Further, if the above AND condition is satisfied, the routine proceeds to routine 9, where a YES determination is made, and the routine proceeds to routine 16. In this routine 16, the output of the terminal number set to "1" by the output control command is turned on. After that, in routine 12, the process counter
Step through the PC and return to Routine 1. in this way,
The output of the terminal number set to "1" by the output control command is turned on or off depending on the success or failure of the AND condition, and the process counter PC is incremented regardless of the success or failure of the AND condition and the next command is executed. We proceed to The scanning type processing of the OR instruction is also the same as described above, so it will not be described in detail. This scanning type processing continues until the scan flag SF is returned to "0" by the conditional jump command, YES is determined in routine 6, and the process counter PC is incremented in routine 4. . In the embodiments described above, scanning-type processing can be performed for AND instructions and OR instructions, but the present invention is not limited thereto, and scanning processing can also be performed for other instructions. As described in detail above, the present invention provides a process update instruction in which a user command for each process unit stored in a program storage unit in association with a process number includes a process update command representing conditions for transitioning from the own process to another process, etc. Consists of output control instructions that indicate whether to turn on or turn off the output of each output terminal during the execution period of the own process, in a one-to-one correspondence with each output terminal number and expressed as "1" and "0". The central processing unit reads the user instructions for each process from the program storage unit, maintains the output state expressed by the output control instruction until the condition expressed by the process update instruction is satisfied, and maintains the output state expressed by the output control instruction until the condition expressed by the process update instruction is satisfied. In a step-by-step programmable sequence controller that updates the process when the process is met, in response to a specific scanning start command set as a user command, and determining whether the conditions for returning from scanning to step-by-step processing are met. The series of user commands set up to the conditional return command that instructs the output terminal number set to "1" by the output control command depending on the success or failure of the condition expressed in the process update command. The system is characterized by a scanning process that turns the output on or off and updates the process immediately regardless of the success or failure of the above conditions.This makes the command system extremely easy to understand. Process progressive type controllers can execute part of the program as needed in the same way as scanning type controllers, and can easily accommodate various control specifications required by users, offering a wide range of use and versatility. Expanded.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the electrical configuration of a sequence controller according to the present invention, FIG. 2 is an external view thereof, and FIG. 3 is a flow chart showing the basic operation of the same controller. 2...Central processing unit, 3...Input circuit, 4...
Output circuit, 5...program storage section, 6...key input device, 7...display device.

Claims (1)

[Claims] 1. User commands for each process stored in the program storage unit in association with process numbers include process update commands representing conditions for transitioning from the current process to another process, and the execution period of the current process. The central processing unit reads the user commands for each process from the program storage section, maintains the output state represented by the output control command until the condition represented by the process update command is satisfied, and when the condition is satisfied, the process is started. In a step-by-step programmable sequence controller that updates the step-by-step programmable sequence controller, a conditional function that responds to a specific scanning start command set as a user command and instructs to determine whether a condition for returning from scanning to step-by-step processing is met is established. A series of user commands set up to the return command are set to "1" by the output control command depending on the success or failure of the condition expressed by the process update command.
A step-by-step programmable sequence that is characterized in that it turns on or off the output of the output terminal number to which it is set, and executes scanning processing that immediately updates the process regardless of whether the above conditions are met or not. Controller control method.