JPH09244714A - Programming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the programming device which can perform efficient programming by improving the input efficiency of an I/O number when a sequence program is generated. SOLUTION: According to information supplied from a keyboard 22 or mouse 20, an I/O number list consisting of I/O numbers to be given to previously stored symbols is displayed on the screen of a CRT 18 at least partially together with a ladder diagram and once a specific I/O number to be given to one symbol is selected out of the display I/O number list with the mouse 20, the selected I/O number is given to the symbol. Specially, the I/O number which is given to the symbol and already used and unused I/O numbers are displayed on the screen of the CRT 18 distinctively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a programmable controller (PC) programming device, and more particularly,
The present invention relates to a programming device for inputting an I / O number and the like when creating a ladder diagram.

[0002]

2. Description of the Related Art Programmable controller (PC)
Stores a specific sequence program for controlling a machine or a process in a memory, and executes calculation, sequence control, etc. based on an instruction constituting the sequence program. When inputting a sequence program to be stored in the memory of such a PC, the CR
With reference to a ladder diagram displayed on a display device such as T, input symbols are input in a predetermined order using an input device, or a specific assembly language is used to specify a specific order in a predetermined order. You are entering an instruction.

For example, Japanese Patent Laid-Open No. 4-348404 discloses that
A programming device for creating a ladder diagram is disclosed. According to this technique, at the position of the input position cursor in the display device, the desired symbol, and
A parameter, that is, an I / O number is input using an input device, and a symbol and a parameter are stored in predetermined areas of the memory, respectively, and a program is created.

[0004]

However, the conventional program input device can be used when inputting an I / O number to be given corresponding to a symbol arranged at a certain position in a ladder diagram. Enter the intended I / O number on a piece of paper, etc., and from this you can use an I / O number that has not been assigned to the symbol, or an I / O number that has already been used but you want to use it again. It is necessary for the operator to select, and input it using the input device.

In addition, it may be preferable to describe, as a comment, the processing contents relating to the symbol arranged at a certain position in the ladder diagram. In such a case, in the conventional program input device,
Separate from the screen for creating the ladder diagram, I / O
The screen for entering a comment associated with a number is CR
Displayed on T, the operator has entered a predetermined comment so as to correspond to the desired I / O number. That is,
It was necessary to enter the comment completely separately from the creation of the ladder diagram.

The present invention is an I / O for creating a PC sequence program using a programming device.
An object of the present invention is to provide a programming device that can improve the efficiency of inputting numbers and efficiently execute programming.

[0007]

It is an object of the present invention to display means for displaying a predetermined image on the basis of the information inputted by the input means, and a screen position for designating a desired position on the screen of the display means. A programming device that includes a designating unit and obtains a sequence program for a programmable controller by creating a ladder diagram on the screen using the inputting unit and the screen position designating unit. I / O number storage means for storing an I / O number intended to be given to the symbol selected based on the information given by at least one of the screen position designating means, and another one given by the at least one. Based on the information, an I / O number list consisting of I / O numbers stored in the I / O number storage means is created. The symbol should be given to the symbol from the table creating means and the I / O number list created by the list creating means and displayed at least partially with the ladder diagram on the screen of the display means. An I / O number assigning unit that assigns the selected I / O number to the symbol in response to the predetermined I / O number being selected by the screen position designating unit. Is achieved by a programming device.

According to the present invention, the operator selects a desired I / O number from the I / O number list displayed at least partially along with the ladder diagram on the screen of the display means. Since it is possible to assign an I / O number to a symbol, it is possible to efficiently create a sequence program without a complicated procedure.

In a preferred embodiment of the present invention, the list forming means displays the I / O numbers which have been assigned to the symbols and which have already been used and unused I / O numbers in a distinguishable manner. , Is configured to create the I / O number list.

According to this embodiment, the operator can easily identify the already used I / O number and the unused I / O number by referring to the image obtained on the screen of the display means. Therefore, the sequence program can be created more efficiently.

In a preferred embodiment of the present invention, an I / O comment table for storing I / O comments corresponding to each of the I / O numbers is further provided, and the I / O comment table of the input means and the screen position designation means is further provided. In response to further information given from at least one, a predetermined I / O comment in the I / O comment table is displayed on the screen of the display means together with the I / O number list. The I / O comment control means is provided.

According to this embodiment, the I / O comment corresponding to the I / O number can be obtained together with the I / O number on the screen of the display means.

[0013] In a further preferred aspect of the present invention, the I / O comment control means creates an I / O comment correspondence table in which the I / O number and the I / O comment are associated with each other, and the display is performed. The I / O comment correspondence table is displayed on the screen of the means.

In a further preferred aspect of the present invention, the I / O comment control means further searches for an I / O number corresponding to the I / O comment designated by the screen position designation means, and The / O number assigning means is configured to assign the retrieved I / O number to the symbol. Thus, the I / O number is specified by referring to the I / O comment, and the specified I / O number is specified.
It is possible to give an O number to the symbol.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a programmable controller (PC) according to an embodiment of the present invention.
3 is a block diagram showing the programming device of FIG. 1 and a PC connected to the programming device. As shown in FIG. 1, the programming device 10 controls C for controlling program creation processing of the programming device.
The PU 12, the memory 14 for temporarily storing data and the like required during the processing of the creation processing program by the programming device 10, the creation processing program for creating the program for the PC, and the result obtained by executing the creation processing program. An external storage device 16 for storing the stored PC program, a CRT 18 for displaying a ladder diagram for creating the PC program, and a mouse 20.
A keyboard 22 and a serial interface (I / F) 24 for transmitting necessary data to the PC.

The PC 30 is the programming device 1
Serial I / F3 that accepts data sent from 0
2, a memory 34 for storing a PC program or the like given from the programming device 10, and a memory 3
4, a CPU 36 that executes a predetermined process according to the program stored in the memory 4, and an I / O 38 connected to an external process (not shown).

The program device 10 thus configured
In the following, the process of creating the program for PC will be described in detail below. FIG. 2 is a flowchart showing an outline of a creation processing program executed by the CPU 18 of the programming device 10 to create a PC program. As shown in FIG. 2, in this program creating process, first, when the operator operates the mouse 20 or the keyboard 22 to give predetermined information to the CPU 12 of the program device 10, the CPU 12 causes the external storage device 1 to operate.
The creation processing program stored in 6 is read out and stored in the memory 14. Next, the CPU 12 CRs the predetermined image according to the program in the memory 14.
It is displayed on the screen of T18 (step 201). Here, FIG. 3 is a diagram showing an example of an image displayed on the screen of the CRT 18.

As shown in FIG. 3, the screen 300 is provided with a ladder diagram creation window 301 and a contact / coil input window 302. The ladder diagram creation window 301 is an area for arranging symbols such as contacts selected from the contact / coil input window 302. Further, the coil / contact input window 302 is obtained by operating the mouse to specify the symbol display position 303, and symbols such as contacts and coils specified by operating the mouse 20 are displayed. In this embodiment, the a-contact symbol 310, the b-contact symbol 311 and the coil 3 are included.
Select the desired symbol from 12 and press the corresponding buttons 313, 3
A desired button of 14 and 315 can be selected by operating the mouse 20.

Further, as described later, by operating the mouse 20 in a predetermined manner,
An I / O number display window 320 for displaying an I / O number to be given to the symbol or already given to the symbol, and an I / O comment description window 321 for describing an I / O comment can be displayed.

The operator operates the mouse 20 or the keyboard 22.
When given information is given to the CPU 18 using
U18 performs contact selection processing 202 according to the program.
Is executed (step 202). FIG. 4 is a flowchart showing the contact selection processing. As shown in FIG. 4, in this process, it is first determined whether or not the button 313 corresponding to the a-contact is selected (step 401). If YES (Y) is determined in this step 401, the a contact is set to the selected state (step 402). On the other hand, if NO (N) is determined, the button 314 corresponding to the b contact is pressed. It is determined whether or not it has been selected (step 403). If it is determined to be yes (Y) in this step 403, the b contact is selected (step 404). On the other hand, if it is determined to be no (N), then the button 315 corresponding to the coil is selected. It is determined whether or not is selected (step 405). If YES (Y) in this step 405, the coil is selected. In this way, when the operator operates the mouse to select any of the buttons 313 to 315 in the coil / contact input window 302 of FIG. 3, either the a contact, the b contact, or the coil is selected. The selected symbol is placed at the symbol display position 303 in the screen 300 of the CRT 18.

Next, the CPU 18 executes an I / O number list selection process (step 203). In this process, as shown in FIG. 5, it is determined that the operator operates the mouse 20 or the keyboard 22 to select one of the R button 330, the X button 331, and the Y button 332 in FIG. . More specifically, the R button 33
If it is determined that 0 is selected, R (internal I / O)
Processing for displaying a list of I / O numbers related to X (external I / O) when it is determined that the X button 331 has been selected (steps 501 and 502) (Steps 503, 50
4) Alternatively, when it is determined that the Y button 332 is selected, a process of displaying a list of I / O numbers related to Y (external output) is executed (steps 505 and 506). These I / O numbers are stored in the external storage device 16. For example, when the creation process of the PC program is started, the I / O number is stored together with the creation process program in the external storage device 16.
Read out from and stored in a predetermined area of the memory 14.

In this list display process, as shown in the flowchart of FIG. 6, first, the display start I / O number which is the first number of the I / O numbers to be displayed is set (step 6).
01). This display start I / O number corresponds to the top number of the I / O numbers finally displayed on the screen in the list obtained by the previous process. Also, when this process is executed for the first time after the device is started up, R00
The smallest I / O number, such as 0 or X000,
The display start I / O number is used.

Next, it is judged whether or not the I / O number is in use (step 602), and if it is in use,
Decide to display the I / O number in reverse video (step 6
03), on the other hand, if it is unused, its I / O
Decide to display numbers normally (step 60)
4). Whether this I / O number is used or not
It means whether or not the O number is associated with at least one symbol.

After steps 605 and 606, the processes of steps 602 to 604 are executed for all I / O numbers to be displayed, and then the process ends. By this list display processing, the I / O associated with the contact by the operator is displayed on the screen of the CRT 18.
O number is displayed in reverse, while unused I / O
The numbers are printed normally. It will be understood that the example shown in FIG. 3 is an image obtained as a result of the operator operating the mouse 20 or the like and selecting the R button 330.

Further, I / O number list selection processing (see FIG. 2)
After step 203), the I / O number selection processing is executed (step 204). This process is shown in the flowchart of FIG. First, it is determined whether the selection state has been changed (step 701). This is CRT18
In the I / O number display window 320 of the screen 300 of
It is determined whether any of the / O numbers is designated by clicking the mouse 22. If it is determined to be no (N) in this step, the process ends, while if it is determined to be yes (Y), the designated I / O number is set to the selected state (step 702). ). In the present embodiment, the designated I / O number is displayed in a color different from the color normally displayed.

Next, it is judged whether or not there is an I / O comment corresponding to the designated I / O number (step 703). This I / O comment will be described in detail later. If it is determined to be no (N) in this step, the process ends, while if it is determined to be yes (Y), the I / O comment is displayed in the I / O comment display window 321 ( Step 704).

Further, the CPU 12 executes a comment input process (step 205). As shown in the flowchart of FIG. 8, in the comment input process, the operator operates the mouse 20 to move the cursor to the I / O comment display window 321, and the keyboard 22
It is determined whether or not any input such as letters or numbers has been made by using (step 801). If YES is determined in step 801, this input is temporarily stored in a predetermined area of the memory 14 (step 802).

After the comment input process (step 205), the CPU 12 executes a comment selection process (step 206). As shown in the flowchart of FIG. 9, in this process, it is first determined whether or not a selection input has been made (step 901).

This selection input is to move a mouse cursor (not shown) to a button provided on the side of the I / O comment display window 321, and in that state, the operator clicks the mouse 20. It means that. If YES is determined in step 901, the CPU 12 reads from the external storage device 16,
The I / O information storage table temporarily stored in the memory 14 is referred to. FIG. 10 is a memory map showing the configuration of the I / O information storage table. As shown in FIG. 10, in the I / O information storage table 100, I / O numbers corresponding to respective I / O numbers intended to be used are stored.
I / O comment storage area 110 for storing I / O comments
And a use count storage area 111 for storing the use count in the ladder diagram of the I / O number. As shown in FIG. 10, the I / O information storage table 10
Initially, only the I / O number is stored in 0, no data is stored in the corresponding I / O comment storage area, and 0 is stored in each of the use count storage areas 111. Is remembered.

If YES is determined in step 901 of FIG. 9, the CPU 12 refers to this I / O information storage table, and the CRT 1 is currently set.
8 I / O comment display window 32 on screen 300
The I / O comment corresponding to the I / O number next to the I / O number displayed in 1 is displayed (step 902).
Next, the CPU 12 brings the I / O number corresponding to the displayed I / O comment into the selected state (step 90).
3). As a result, the selected I / O number is displayed in a color different from the color normally displayed in the I / O number display window 320 of the screen 300 of FIG.

Next, the CPU 12 executes the input determination process (step 207 in FIG. 2). This process is shown in Figure 1.
It is shown in FIG. In the input determination process, the operator uses the mouse 2
By operating 0, it is determined whether or not the OK button in the screen 300 of FIG. 3 has been clicked (step 1
101). If it is determined to be no (N) in step 1101, the process is terminated, while if it is determined to be yes (Y), the contact selected by the contact selection process (step 202 of FIG. 2). And the finally selected I / O number as the program information in the memory 1
4 (step 1102). This program information corresponds to one step of the PC program. Next, with reference to the I / O information storage table 100, the number of times of use corresponding to the selected I / O number is incremented (step 1103).

The CPU 12 examines a predetermined area of the memory 14 and determines whether or not the comment is temporarily stored in the comment input process of step 205 (step 1104). The comment is temporarily stored. If so, it is stored in the I / O information storage table so as to correspond to the selected I / O number (step 11).
05). In this way, the I / O number corresponding to a certain contact is associated with the related I / O comment.

After the above processing is completed, the operator operates the mouse 20 or the keyboard 22 and selects the window close button 342 (see FIG. 3) to give the information indicating the end of input ( Step two
08), the contact / input window 302 is closed, and the process ends. On the other hand, when the information indicating the end of input is not given, the input of the symbol corresponding to the next step of the program for PC is executed.

As described above, the combination of the type of symbol such as a contact and the I / O number, which is selected by using the programming device 10 according to the present embodiment and stored in the memory 14 of the programming device 10, is used. Based on this, a program for PC is obtained. The obtained PC program and I
The / O information management table is stored in the external storage device 16, the PC program is read by the CPU 12 when necessary, and the PC 3 is read via the serial I / F 24.
0 is transmitted to the serial I / F 32.

The CPU 36 of the PC 30 is the given PC
Program for memory is stored in the memory 34, and the instructions of the program are sequentially read out from the memory 34 as needed, and
Control the process (not shown) via O38.

Next, when creating a program using the programming device 10 according to this embodiment, the CRT 1
The programming device 10 will be described more specifically on the basis of images displayed on the screen of FIG.

On the screen shown in FIG. 3, the operator operates the mouse 20, moves the mouse cursor (not shown) to the symbol display position 303, and clicks the mouse 20 to open the contact / coil input window 302. , Screen 3
Displayed above 00.

For example, the operator may move the display position 303 to
When inputting an a-contact, the a-contact button 313 in the contact / coil input window 302 is designated by using the mouse 20 (see FIG. 12A). By such an operation, the a contact is brought into the selected state in the contact selection processing of step 202 of FIG. 2 (see step 401 and step 402 of FIG. 4). Further, by selecting the R button 330, the I / O number list display process regarding R is executed in step 203 of FIG. 2 (see steps 501 and 502 of FIG. 5, and FIG. 6), and as a result,
I / O numbers related to R are displayed in a list. Then, the operator selects the desired I / O number in the I / O number display window 320.
If you select the O number (eg R000), you will see I in Figure 2.
A predetermined process is executed in the I / O number selection process (step 204), and the I / O number R000 is selected.

Further, the operator moves the mouse cursor to the comment display window 321, and inputs a desired comment using the keyboard 22. This input comment is temporarily stored in a predetermined area of the memory 14 in the comment input process of step 206 of FIG. 2 (see step 802 of FIG. 8). FIG. 13 is a memory map showing the I / O information storage table after the operator inputs a comment for the I / O number R000. As shown in FIG. 13, the I / O comment storage area 11
Area 110-1 corresponding to I / O number R000 in 0
The I / O comment "Conveyor 1 operating condition" input by the operator is stored in the field, the corresponding I / O number is incremented from 0 to 1, and the I / O number in the use count storage area 110 is increased. Area 111-1 corresponding to the number
The number of times of use is stored in.

After the operation by the operator and the operation by the programming device 10 as described above, the operator can accept the operation.
When the button 350 is selected, various information given to the contact / coil input window 302 is confirmed. That is, in the input determination process of step 207 of FIG. 2, the processes of steps 1102, 1103 and 1105 of FIG. 11 are executed. As a result, as shown in FIG. 12B, the contact a and the I / O number are displayed at the desired position 360. The I / O number and the I / O comment do not necessarily have to be selected or entered at the same time when the contact point or the coil is selected, but may be selected or entered when desired by the operator. If there is no need, I / O comment need not be entered. In addition, the operator
This contact / coil input window remains open unless 0 is operated to select the window close button 342.

Further, in FIG. 12A, the I / O number selected by the user in the I / O number display window 320, that is, R000, is displayed in a color different from other I / O numbers. It should also be noted that in FIG. 12B, this R000 is in use and is therefore displayed in reverse video.

Next, a process in which the operator operates the mouse 20 to give a predetermined symbol or the like to the new display position 361 will be described. As shown in FIG. 14A, when the operator operates the mouse 20 to specify the b-contact button 314 and selects the X button 331, the I / O number relating to X is displayed as the I / O number. A list is displayed in the window 320. Here, if X101 has already been used once for another contact b in the ladder diagram, the I / O number X101 is displayed in reverse, unlike the display of other I / O numbers. This is step 203 in FIG.
In the XI / O number list display process (step 504 in FIG. 5) during the I / O number list selection process of the above, a process for highlighting the I / O numbers already in use is executed. (Step 602 and Step 6 in FIG. 6)
03).

Next, the operator operates the mouse 20 to select this I / O number X101 and
"Stop button input" in the O comment entry window 341
After inputting the I / O comment, OK button 35
When 0 is selected, as shown in FIG. 14B, the symbol of the b contact and the I / O number X101 are displayed at the display position 361.

When the programming device 10 is operated by such an operator's operation, as shown in FIG. 15, the I / O comment storage area 110 of the I / O information storage table 100 in the memory 14 stores I / O. Information 11 associated with the character "stop button input" corresponding to the number X101
0-2 is stored. Also, the I / O information storage table 1
In the number-of-uses storage area 111 of 00, information 111-2 related to the number 2 is stored corresponding to the I / O number. In this information 111-2, the I / O number X101 is used once for the other contact b in the ladder diagram. As a result, the number of times of use is 1 to 1 in the input determination process of step 207 of FIG. This is because it is incremented to 2 (see step 1103 in FIG. 11).

According to the present embodiment, when the ladder diagram of the sequence program for PC is created, the necessary I / O number is displayed on the CRT screen.
It becomes possible to select from the number list. Therefore, it becomes possible to easily input a desired I / O number without the complicated procedure of the operator inputting each character one by one like the conventional input of the I / O number.

Further, according to the present embodiment, in the I / O number list displayed on the screen of the CRT, the already used I / O numbers and the unused I / O numbers are separated. Since they are displayed separately, it is possible to easily check the unused I / O number when selecting the I / O number.
As a result, programming efficiency can be improved.

Furthermore, according to the present embodiment, when selecting an I / O number, an I / O comment related to the I / O number can be input, so that the programming efficiency can be further improved. It will be possible. Also, I selected
When an I / O comment is already assigned to the I / O number, the I / O comment associated with the I / O comment in the I / O information storage table is displayed on the screen of the CRT. Therefore, the operator can input the I / O number while referring to this I / O comment and confirming the definition of the I / O number.
It is possible to reduce input mistakes of O number.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. It goes without saying that this is what is done.

For example, in the above-described embodiment, as shown in FIG. 2, the processes constituting the creation processing program are configured to be executed serially, but the present invention is not limited to this. Alternatively, the information provided from an input device such as a mouse or a keyboard may be discriminated and a predetermined process may be executed in response to the type of the provided information.

In the above embodiment, the I / O
Although it is configured to input an I / O comment when selecting a number, the number is not limited to this. For example, in addition to or instead of the configuration described above,
An image including the table shown in FIG. 16 is displayed on the screen of the CRT, and the keyboard is operated to correspond to the I / O number,
It may be configured to input a desired I / O comment. In this case, the CPU 12 stores an I / O comment associated with one or more I / O numbers in a predetermined area of the memory in response to the input of the I / O comment, and After the information indicating the end of the input of the O comment is given from the input device, the I / O comment temporarily stored in the memory is stored in the I / O information management table.
Further, the table shown in FIG. 16 is displayed on a part of the screen 300 of FIG. 3, and the operator operates the mouse to select the I / O comment in the displayed table. O
It may be configured to select a number.

Further, in the above-mentioned embodiment, the contact a, the contact b
Although a desired symbol is selected from the contacts and the coil to create the ladder program, it is obvious that a configuration other than the above-mentioned symbols may be selected.

Further, in the present specification, the term "means" does not necessarily mean physical means, but also includes the case where the function of each means is realized by software. Further, the function of one means may be realized by two or more physical means, or the functions of two or more means may be realized by one physical means.

[0053]

According to the present invention, when a PC sequence program is created using a programming device,
It is possible to improve the input efficiency of the I / O number and provide a programming device capable of efficiently executing programming.

[Brief description of drawings]

FIG. 1 is a programming device of a programmable controller according to an embodiment of the present invention, and
3 is a block diagram showing a PC connected to a programming device.

FIG. 2 is a flowchart showing an outline of a creation processing program executed by a CPU of a programming device to create a PC program.

FIG. 3 is a diagram showing an example of an image displayed on the screen of the CRT according to the present embodiment.

FIG. 4 is a flowchart showing contact selection processing executed by the CPU according to the present embodiment.

FIG. 5 is a flowchart showing an I / O number list selection process executed by the CPU according to the present embodiment.

FIG. 6 is a flowchart showing a list display process executed by the CPU according to the present embodiment.

FIG. 7 is a flowchart showing an I / O number selection process executed by the CPU according to the present embodiment.

FIG. 8 is a flowchart showing comment input processing executed by the CPU according to the present embodiment.

FIG. 9 is a flowchart showing a comment selection process executed by the CPU according to the present embodiment.

FIG. 10 is a memory map showing a configuration of an I / O information storage table according to the present embodiment.

FIG. 11 is a flowchart showing an input determination process executed by the CPU according to the present embodiment.

FIG. 12 is a diagram showing an example of an image displayed on the screen of a CRT.

FIG. 13 is a memory map showing an example of an I / O information storage table.

FIG. 14 is a diagram showing an example of an image displayed on the screen of a CRT.

FIG. 15 is a memory map showing an example of an I / O information storage table.

FIG. 16 is a diagram showing an example of a table that can be displayed on the screen of a CRT.

[Explanation of symbols]

 10 programming device 12 CPU 14 memory 16 external storage device 18 CRT 20 mouse 22 keyboard 24 serial I / F

Front page continuation (72) Inventor Norihiro Aida No. 46 Tomioka, Nakajo-cho, Kitakanbara-gun, Niigata Prefecture 1 Industrial Equipment Division, Hitachi, Ltd. (72) Mana Soga 46 No. 1 Tomioka, Nakajo-machi, Kitakanbara-gun, Niigata Prefecture Hitachi Industrial Equipment Division

Claims (5)

[Claims] 1. A display means for displaying a predetermined image on the basis of the information given by the input means, and a screen position designating means for designating a desired position on the screen of the display means. By using the screen position designating means to create a ladder diagram on the screen,
A programming device for obtaining a sequence program for a programmable controller, the I / O number being intended to be given to a symbol selected based on information given by at least one of the input means and the screen position designation means. I /
O number storage means, and a list creation means for creating an I / O number list consisting of I / O numbers stored in the I / O number storage means based on other information given by the at least one. , Created by the list creating means,
Further, a predetermined I / O to be given to the symbol is selected from the I / O number list displayed at least partially with the ladder diagram on the screen of the display means.
A programming device comprising: an I / O number assigning unit that assigns the selected I / O number to the symbol in response to a number being selected by the screen position designating unit. 2. The list creation means adds the I / O numbers that have been used to the symbols and have already been used, and the unused I / O numbers.
The programming device according to claim 1, wherein the I / O number list is created so as to be displayed separately from the O number. 3. An I / O comment table for storing I / O comments corresponding to each of the I / O numbers, further comprising: an I / O comment table provided from at least one of the input unit and the screen position designating unit. I / O comment control means for displaying a predetermined I / O comment in the I / O comment table together with the I / O number list on the screen of the display means in response to other information. The programming device according to claim 1 or 2, further comprising: a programming device. 4. The I / O comment control means sets the I / O comment control means.
An I / O comment correspondence table that associates the I / O number with the I / O comment is created, and the I / O comment correspondence table is displayed on the screen of the display means.
6. The programming device according to claim 4, wherein the programming device is configured to display an / O comment correspondence table. 5. The I / O comment control means retrieves the I / O number corresponding to the I / O comment designated by the screen position designating means, and the I / O number assigning means stores the I / O number. The programming device according to claim 3 or 4, wherein the programming device is configured to give a searched I / O number to the symbol.