JPS58225403A - Programmable controller - Google Patents

Abstract

PURPOSE:To ensure the simple programming without having any redundant programming, by connecting the function of a drum type sequencer directly to the substance of the control contents of the sequencer by means of a programmable controller and therefore excluding an intermediate logic process. CONSTITUTION:In order to attain the function of a drum type sequencer, a start signal S, a signal U/D which designates the up/down counting of a counter, an advance signal CK and a reset signal R are used respectively in a drum counter instruction. The signals S, U/D, CK and then R are set successively as a load instruction LD, and then a drum counter instruction DRUM is set. Then a certain bit of a state memory 61 corresponding to an output number is set at ''1'' and ''0'' if the counter value is within and outside the range of upper/ lower limit value respectively corresponding to each drum output number of a set table when the instruction DRUM is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of the Invention The present invention relates to a scanning-type programmable controller represented by a relay ladder diagram, and particularly to one that can easily realize the same functions as a drum-type sequencer. .

(2) Conventional technology and its problems Conventional relay ladder diagrams and other general programmable
In the controller, a drum-type sequencer (a cam that operates or does not operate around a rotatable drum is installed), and this cam operates a microswitch, and a step signal causes the drum to rotate by a certain rotation angle. To achieve the same control function (new operation signals can be extracted one after another as the process progresses), shift register instructions and stepping switch instructions are known.

Programming can be done using a combination of counter instructions and data comparison instructions.

What is essentially required to realize the control function of a drum-type sequencer is information on the conditions of the stepping signal that controls the rotation of the drum and the position of the cam attached to the periphery of the drum. Nevertheless, when trying to implement the functions of a drum-type sequencer using the above-mentioned instructions with a conventional programmable controller, it is necessary to create a very redundant program, which makes programming cumbersome and error-prone. The problem is that it is easy. In other words, although the final control function is not so complicated, the lack of dedicated instructions necessitates the creation of redundant programs that include complex intermediate logic processes. In addition, because it includes such intermediate logical processes, when revising the program to partially change the control contents, the program contents are very difficult to read and therefore difficult to change, and errors may occur. It was easy.

(3) Purpose of the Invention The purpose of the present invention is to provide a programmable controller in which the functions of a drum-type sequencer can be programmed extremely easily in a manner that is directly connected to the essence of its control content, eliminating unnecessary intermediate logic processes. Our goal is to provide the following.

(4) Structure and Effects of the Invention In order to achieve the above object, the present invention includes a counter means that can be arbitrarily controlled by a user program, a state memory that can be arbitrarily read out bit by bit by the user program, a setting value table in which data indicating a numerical range is stored in areas associated with each bit of the state memory; and input means for writing arbitrary numerical range data into the setting value table; When an instruction related to the counter means in the user program is executed, the count value of the counter means and the number 1a of the set value table are calculated.
Comparing means for sequentially comparing the counted value with the range data to determine whether or not the counted value is within a set numerical range; and logic of each bit of the state memory corresponding to each numerical range data according to the determination result of the comparing means. The invention is characterized by a state update means for determining the state.

5.) A. 5.A7. ．． Tsua. -5,, yo□1,
By setting the control conditions for the counter means (referred to as drum counter) in one user program and writing arbitrary numerical range data in the setting value table, each bit of the state memory can be set to n of the drum counter.
It changes to 1'' or 0'' according to the digit operation, and each bit can be used arbitrarily in the user program.

In other words, the step condition of the drum of the drum type sequencer corresponds to the step condition of the drum counter mentioned above, and the position of the cam provided around the drum corresponds to the numerical range data mentioned above. Programming can be done using almost the same simple logic, and there is no need to program some of the troublesome intermediate logic processes required in the past.

In addition, the numerical range data stored in the setting value table is separated from the series of steps in the knee IF program.
(This prevents you from accidentally rewriting the numerical range data mentioned above when changing a part of the user program, or accidentally destroying the user program when rewriting the numerical range data, and this also makes programming easier.) It becomes very easy.

(5) Description of Embodiments FIG. 1 is a block diagram showing the general structure of a one-gram pull controller to which the present invention is applied. This programmable controller number is CPU1 (Central Processing Unit), which is the center of overall control, and CPU1.
A system program memory 2 that stores system programs executed by CPtJl, a working memo memory 3 used by CPtJl as a temporary storage area for various variable data, and a sequence lli arbitrarily set by the user.
User program memory 4 in which control programs are stored
, an input/output device 5 including an input interface to which an external input signal is given and an output interface to send an external output signal, and an area serving as a buffer memory 1 for input/output data corresponding to one core for the input/output device 5. There is also an input/output memory 6 for storing other circuit data such as internal relays and auxiliary circuits, and an input/output memory 6 for giving various operation commands to the CPU 1, inputting user program creation, and inputting commands to the monitor 4u. The program console 7 is also provided with a program console 7 on which information is input, displayed on a monitor, etc.

Note that in a relatively small-scale programmable controller, the CPU 1, system program memory 2. Working memory 3 and input/output memory 6 are constructed of a so-called one-chip microcomputer.

As is well known, the execution operation of a user program in this type of programmable roller is to sequentially read out user commands from the user program memory 4 and transfer input/output data stored in the input/output memory 6 according to each user command. , and update designated input/output data based on the results of the calculation, and in synchronization with the execution of this user program, the input data given to the input/output device 5 is transferred to a predetermined area of the input/output memory 6. (input update), and transfers the output data of a predetermined area of the input/output memory 6 to the input/output device 5 (output update). In relation to the external output signal output from the device 5, a sequence state specified by the user program is created.

The arithmetic processing results of this user program include not only the input/output data of the input/output device 5, but also the data stored in the input/output memory 6 or linking memory 3, which are so-called internal relays and auxiliary relays. As is well known. It is also well known that the memory 3 or the memory 6 can be used to perform processing that handles numerical data, such as so-called timer instructions and counter instructions. In some cases, it is also possible to process shift register instructions and stepping switch instructions.

Next, a description will be given of the drum counter command, which is the main part of the present invention for realizing the same control function as the drum type sequencer 1. FIG. 2A shows a symbolic representation of a drum counter command on a relay ladder circuit diagram. FIG. 2B is a table in which the drum counter commands are expressed in 21 monic words, one word at a time. The drum counter command of this embodiment uses four types of input signals @S, U/D, OK,
R is required. S is a start signal for operating the drum counter. U/D is a signal specifying whether the drum counter is to be operated up or down. G
K is a drum counter step signal. R is a drum counter reset signal. When setting the drum counter command as shown in (B), each of the above input condition signals S,
Set Ll/D, GK, and R in this order as a load instruction (LD), then display the drum counter instruction -nDR
Set up UM.

In the programmable controller of the present invention, a setting table 41 shown in FIG. 3 is allocated in the user program memory 4 and a state memory 61 is allocated in the input/output saw memory 6 in order to execute the above-mentioned drum counter command. The drum counter instruction of this embodiment has 10 drum outputs from "1" to "10", and the setting table 41 has an arbitrary numerical range corresponding to each drum output number. An upper limit area and a lower limit area are allocated for setting data.

Arbitrary numerical values can be written in the upper limit area and lower limit area of the setting table 41 by operating the program console 7. Also state memory 6
1 corresponds to each drum output number, each with 1 pit 1~
Data areas 81 to BIO are allocated.

Then, when the drum counter command is executed, the following processing is performed. First, the count value of the drum counter is controlled according to the above four types of input signals. Next, it is compared with 1 to determine whether the counted value is outside the range of the numerical range data set corresponding to each drum output number. If the count value of the counter is within the set numerical data range,
Set one bit of the state memory 61 of the corresponding output number to 1.
If the count value is outside the range of the set numerical data, a certain bit of the corresponding state memory 61 is set to “
0''. Each bit 81 to B1 of this state memory 61
0 can be read arbitrarily by the user program,
This can be used as an output signal as is, or it can be used as a signal to be subjected to some logical operation.

The above processing contents are shown in the flowcharts of FIGS. 4 and 5. FIG. 4 is a schematic flowchart 1 of the user program execution routine. First, the program counter PC for addressing the user program memory 4 is cleared, and the instructions in the user program memory 4 indicated by the program counter PC are read out (steps 100 and 101). Next, check whether the read instruction is an END instruction inserted at the end of the user program (step 102), and check whether the next read instruction is a drum counter instruction (step 103).
), if it is a drum counter command, it is executed in step 104, and if it is another command, it is executed in step 105. After executing the instruction, the program counter PC is incremented in step 106, and the process returns to step 101 to execute the next instruction. When the last END command of the user program is read, the process proceeds from step 102 to step 107, where the input/output update operation described above is performed, and the process returns to the first step 100.
Return to

FIG. 5 is a flowchart 1 to 1 showing details of the drum counter command execution routine in step 104. This is executed when the DRUM instruction is read from user program memory 4. The states of the signals S, U/D, CK, and R are read into the stack in the four instructions before the DRLJ M instruction, but first, in steps 200 to 206,
The drum counter is controlled according to these signals S, ・U/D, CK, and R. That is, if the reset signal R is supplied, the counter is reset to 1-. Also, when the start signal S and the clock signal GK are supplied, the counter is incremented according to the signal state of U/D.
- or decrement. Next, 1 is set in register C for designating the drum output number, and the first output number "1" is designated (step 207). Next, the numerical range data corresponding to the designated number of the register t is read from the setting table 41, and the data is compared with the data of the counter to determine whether it is within the set range (step 208).

If C is within the range, set bit Bt of the state memory 61 to 1'' in step 209; if C is outside the range, step 21
0, the bit Bt of the state memory 61 is set to 1101+.

Next, in step 211, register C is set to the last output number 11.
If it is not rloJ, in step 212, the contents of the register are set to +1.
Then, the process returns to step 208. The above processing is performed up to the output horn number [10J, and the processing for the drum counter command is thus completed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an outline of the hardware configuration of a programmable controller according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of a drum counter command, and FIG. 3 is an explanatory diagram of a setting table 41 and a state memory 61. , FIG. 4, and FIG. 5 are flowcharts showing an outline of the software configuration of the programmable controller. 1... CPU 2... System program memory 3...
・Working memory 4...User program memory 5...
...Input/output horn 1 Input/output memory 7...Program console 41...Setting table 61...Status memory Patent applicant Tateishi Electric Co., Ltd.

Claims (1)

[Claims] (1) Counter means that can be controlled arbitrarily by the user program, a state memory that can be read out in bits by the user program, and numerical ranges shown in areas associated with each bit of this state memory. A set value table in which data is stored, an input means for writing arbitrary numerical range data into this set value table, and a counter means when an instruction related to the counter means in the user program is executed. Dew! Comparison means for sequentially comparing the numerical value and each numerical range data of the set value table to determine whether or not the counted value is within the set numerical range;
and a state updating means for determining the logic of each bit of the state memory corresponding to each numerical range data according to the determination result of the comparison means.
controller.