JPH1195819A - Programming device for programmable controller, connection method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the programming device of a programmable controller for automatically performing inter-terminal connection correct in terms of a circuit by a straight line (horizontal line or vertical line) or an oblique line just by specifying both terminals to be connected by an operator or the like. SOLUTION: By reading and executing an application program stored in a storage part 4 or a portable storage medium 7, when the positions of the start point and end point of the connection are specified through an input part 2 by the operator or the like, the central processing unit CPU 1 for controlling the entire system of this programming device 10 refers to data inside a terminal information storage part 3-2 inside a RAM 3, confirms that the specified start point and end point of the connection are present on the terminal of first and second graphic symbols and both terminals provided on the start point and the end point are turned to the combination of input/output and then, performs a processing for connecting the start point and the end point by the straight line or the oblique line corresponding to specification.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a programming device which is a program creation support tool for a programmable controller.

[0002]

2. Description of the Related Art Programmable controllers (hereinafter referred to as P
In general, a programming device, which is a program creation support tool, is used to create the program C). This programming device is usually separate from the PC, and is used by connecting to the PC when a program is changed, modified, or newly created.

[0003] As a PC programming language, there is known an illustration expression program such as a ladder diagram using graphic symbols such as relay symbols and logic symbols. The creation of an illustration expression program using a programming device is performed by displaying graphic symbols on a display screen, connecting them, and creating a so-called circuit diagram.

By the way, as an illustration expression program used for a PC, there is an expression format called a function block diagram (hereinafter, referred to as an FB diagram) in addition to the ladder diagram and the like. The FB diagram is a logical operation,
A terminal of a "function" graphic symbol (hereinafter referred to as a "function cell") indicating a processing unit such as addition, subtraction, multiplication or division, and an operand graphic symbol (hereinafter referred to as an "operand cell") serving as input data or output data of the function. A program is expressed by connecting a line between a terminal of the function or a terminal of a cell of another function.

FIG. 6 is a diagram showing an example of program creation / display using an FB diagram. In the figure, the sum of the value of the operand “A” and the value of the operand “B” is calculated using the function of addition (+), and the operand “D” is calculated from the calculated sum using the function of subtraction (−). "Is subtracted, and the result of the subtraction is stored in the operand" C "(C = A + B-
D) is an example, and shows a creation procedure and a display method.

First, an operator or the like selects a function of addition (+) and a function of subtraction (-) from a group of instructions displayed on a display screen such as a display by using a keyboard or the like (not shown). Is arranged at a desired position on the display screen. As a result, FIG.
As shown in (a), the graphic symbols (cells) 60 and 70 of the addition (+) function and the subtraction (-) function are displayed at predetermined positions on the display screen, respectively. As shown in the figure, the cell 60 of the function of addition (+) and the cell 70 of the function of subtraction (-) both have a terminal の (input terminal a,
b, output terminal c), (input terminals d and e, output terminal f)}
have.

Next, the operator or the like selects an operand description section (indicated by []) from the instruction group, as in the case of FIG. Perform an operation to place it in the neighborhood of.

By the way, at present, as many F
In order to display B (function block) once (one screen) and to easily understand the contents of a program, cells are being arranged densely. For this reason, there may be no space for arranging the cell 110 of the operand “D” between the cell 60 of the addition (+) function and the cell 70 of the subtraction (−) function shown in FIG. In this case, the operator or the like places the cell 110 of the operand “D” below the cell 60 of the addition (+) function, for example, as shown in FIG.

Subsequently, the operator or the like selects a "straight line (horizontal line or vertical line)" from the instruction group, and as shown in FIG. Perform the operation to connect to the terminal.

At this time, the cell 110 of the operand "D"
(D), as shown in FIG. 3D, a line is connected in a polygonal line to connect the cell “ge” of the operand “D” and the terminal “ge” of the cell 70 of the addition (+) function. I was

[0011]

In the above-described conventional programming device, the operator or the like has to select the "straight line" from the instruction group and perform the work of connecting the terminals of the cells. . In particular, in the case of the connection of the terminal g of the cell 110 of the operand "D", the connection work is complicated, and the work efficiency is reduced. Further, in a dense state in which cells of other functions, operands, etc. are arranged between terminals to be connected, a complicated connection that bypasses these cells is performed, or the cells are moved. It has to be performed, and there is a problem that the working efficiency is reduced.

The connection between the terminals must be performed by a combination of the input terminal and the output terminal. Particularly, when the terminals are densely displayed on the display screen as described above,
Wrong connection was sometimes made due to misunderstanding of the operator or the like. In addition, there is a problem that the work efficiency is reduced if the work of confirming the connection is performed one by one without mistake.

An object of the present invention is to provide a programming device for a programmable controller in which an operator or the like simply specifies both terminals to be connected and automatically connects the terminals with a straight line (horizontal line or vertical line) or diagonal line. It is to provide.

[0014]

According to the present invention, there is provided a programming apparatus for creating a program for operating a programmable controller in a graphical representation on a display screen by connecting graphic symbols and terminals of the graphic symbols. To connect the terminals of the displayed first and second graphic symbols, the starting point of the connection,
Designation means for designating the position of the end point, detection means for detecting the terminals of the first and second graphic symbols present at the start and end points of the connection designated by the designation means, and detection by the detection means Determining means for determining whether or not each terminal is an input / output combination based on the terminal information of each of the terminals, and determining that each terminal is an input / output combination by the determining means. In this case, there is provided a connecting means for connecting the terminals.

The connection means connects the terminals with a horizontal line, a vertical line, or an oblique line, for example, in accordance with a designation from an operator or the like. According to the programming device having the above configuration, the operator or the like can determine the type of connection (horizontal line, vertical line,
Or, simply select the diagonal line and specify the start and end points of the connection.
And that it is on the second terminal, and the combination of each terminal to be further connected is correct (input / output combination)
Then, the terminals are automatically connected.
This eliminates the need for the operator or the like to always check whether the combination between the terminals to be connected is correct or not, and to perform a simple operation of designating the start point and the end point of the connection without causing a connection error. Since the connection work between the terminals can be reliably performed, the work efficiency of creating a program based on the FB diagram is significantly improved as compared with the conventional case.

Furthermore, even if it is conventionally necessary to perform a complicated connection combining horizontal and vertical lines, the connection can be made by diagonal lines, so that the work of connecting the terminals is simplified, and a program is created based on the FB diagram. Work efficiency is significantly improved than before.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the programming device according to the present embodiment.

In FIG. 1, a CPU 1 is a central processing unit for controlling the entire system of the programming device 10. The input unit 2 is, for example, a keyboard, a mouse, or the like, or a touch panel.

The RAM 3 is a storage area for storing information storage units such as a cell information storage unit 3-1, a terminal information storage unit 3-2, a connection information storage unit 3-3, and a connection management information storage unit 3-4. Is a memory having Each of these information storage units 3-1
3-4 will be described in detail later, but this information corresponds to program data created based on cells and the like input and shown by an operator or the like. RA
M3 is backed up by battery and power off
Even when the data is not erased. Or, instead of RAM, re-
An ad / write-capable nonvolatile memory element may be used.

The storage unit 4 is, for example, an HDD (hard disk drive) and stores an OS (operating system), various application programs, and the like.
Furthermore, an application program that provides the function of the programming device according to the present embodiment may be stored.

The display unit 5 is, for example, a display.
For example, the cell information storage unit 3-1 and the terminal information storage unit 3-
2. Connection information storage unit 3-3 and connection management information storage unit 3
-4 is displayed on the screen on the basis of the data stored in -4.

The medium driving device 6 is a device for controlling the CPU 1 to read or write application programs and data stored in a portable storage medium 7 to be described later, for example, an FDD or a CD-ROM.
Such as a drive.

The portable storage medium 7 stores at least an application program for providing the functions of the programming device according to the present embodiment in a format that can be read by the medium drive device 6 and executable by the CPU 1. Is an independently portable storage medium (recording medium). The portable storage medium 17 is, for example, an FD (floppy disk). Alternatively, it may be an MO (magneto-optical disk), CD-ROM, PC card, or the like. In the portable storage medium 17, an application program for providing at least the function of the programming device of the present embodiment can be read by the medium drive device 6 magnetically, magneto-optically, or electrically, and the CPU 1
It is stored in an executable format.

The communication unit 8 transfers the program data stored in the RAM 3 or the like after the completion of the program creation operation to a PC.
11 to a program memory (not shown). Alternatively, when partially modifying the program data stored in the program memory in the PC 11, the PC 1
1 to receive program data transferred from
This is stored in AM3.

The PC 11 is a programmable controller. The programming device according to the present embodiment has a storage area (information storage unit) for storing cell (function cell or operand cell) information, terminal information, connection information, and the like based on the FB diagram input / created in the illustrated representation. , For example, R
It has it in AM3.

FIG. 2 is a diagram showing the data structure of each information storage unit. FIG. 2A shows the cell information storage unit 20 (3-
It is a figure showing the data composition of 1). As shown in FIG. 2A, the cell information storage unit 20 stores a cell type 2 for each cell.
1, a cell name 22, an input number 23, a head position 24 of an input terminal information storage unit, an output number 25, a head position 26 of an output terminal information storage unit, a cell XY coordinate 27, a cell width 28, and a cell height 29 Stores cell information consisting of data.

The cell type 21 is data indicating whether the cell is a function cell or an operand cell. For example, "1" is stored for a function cell, and "2" is stored for an operand cell.

The cell name 22 is, for example, the cell type 21
In the case where the cell is a function cell, data indicating an operation processing unit such as addition / subtraction (+,-) and multiplication / division (×, ÷) is stored. If the cell is an operand cell, Is, for example, "A" shown in FIG.
Data such as "B" and "C" are stored. Here, data such as “A”, “B”, and “C” in the operand are:
For example, this is information indicating the name of a register or the like that stores a value to be input to a function or an operation result of the function.

The number of inputs 23 is data on the number of inputs (number of input terminals) to the cell. The data with 23 inputs is usually '2' if the cell is a function cell,
It is '0' or '1' if the cell is an operand cell.

The head position 24 of the input terminal information storage unit is stored in a terminal information storage unit 30 (FIG. 2) for storing information on each terminal.
(B); this will be described later) is data indicating the head position (head address) of the storage area for storing the information of the input terminal.

The output number 25 is data of the number of outputs (number of output terminals) from the cell. The data with 25 outputs is normally '1' if the cell is a function cell,
It is '0' or '1' if the cell is an operand cell.

The head position 26 of the output terminal information storage unit is data indicating the head position (head address) of the storage area in the terminal information storage unit 30 for storing the information of the output terminal.

The cell XY coordinates 27 correspond to the display section 5 of the cell.
Is the data indicating the arrangement position on the display screen, for example, the (X, Y) coordinate value of the upper left corner of the cell. Then, the cell is displayed on the display screen of the display unit 5 based on the data of the (X, Y) coordinate value, the data of the cell width 28, and the data of the cell height 29.

FIG. 2B shows the terminal information storage unit 30 (3-
It is a figure which shows the data structure of 2). As shown in FIG. 3B, the terminal information storage unit 30 stores an input / output division 31, a corresponding cell information storage position 32, a previous terminal information storage position 33, a next terminal position information storage position 34, Terminal XY coordinate 3
5 and the terminal information composed of each data of the connection management information position 36 are stored.

The input / output division 31 is data indicating whether the terminal is an input terminal or an output terminal. For example, "1" for an input terminal, "2" for an output terminal
Is stored.

The corresponding cell information storage position 32 is data indicating the position where the information of the cell corresponding to the terminal in the cell information storage unit 20 is stored, in other words, the cell of the function or the cell of the operand having the terminal. This is data indicating a head position of a storage area in the cell information storage unit 20 in which cell information is stored.

The previous terminal information storage position 33 is data indicating the head position of a storage area in the terminal information storage section 30 in which terminal information before the terminal concerned is stored. The next terminal information storage position 34 is data indicating a head position of a storage area in the terminal information storage unit 30 in which terminal information next to the terminal is stored.

Note that the previous or next terminal information in the previous terminal information storage location 33 and the next terminal information storage location 34 is for input terminals or output terminals in the same cell. Therefore, even if terminal information of an output terminal is stored next to terminal information of a certain input terminal, data is not stored in the next terminal information storage position 34 of the input terminal ("0").

The terminal XY coordinates 35 are (X, Y) coordinate data indicating the display position of the terminal on the display screen.
The connection management information location 36 stores a connection management information storage unit 50 (FIG. 2) in which connection management information corresponding to the terminal is stored.
(D); this is data indicating the start position of the storage area in (described later).

FIG. 2C shows the connection information storage unit 40 (3-
It is a figure which shows the data structure of 3). As shown in FIG. 3C, the connection information storage unit 40 stores a connection start X for each connection.
The connection information including the data of the Y position 41, the connection end XY position 42, and the connection management information position 43 is stored.

The connection start XY position 41 and the connection end XY position 42 are data of (X, Y) coordinates of a start point and (X, Y) coordinates of an end point of the connection, respectively. The connection management information position 43 is data indicating a head position of a storage area in the connection management information storage unit 50 in which connection management information corresponding to the connection is stored. .

FIG. 2D shows the connection management information storage unit 50.
It is a figure showing the data composition of (3-4). As shown in FIG. 3D, the connection information storage unit 50 stores, for each connection, a connection information storage position 51, start point connection destination information 52 (information indicating whether the connection destination of the connection start point is a terminal or a connection), A start point connection destination terminal information storage position 53, a start point connection destination connection information storage position 54, an end point connection destination information 55 (information indicating whether a connection destination of a connection end point is a terminal or a connection), an end point connection destination terminal information storage position 56, and The connection management information including the data of the destination connection information storage location 57 is stored.

The connection information storage position 51 is data indicating the head position of a storage area in the connection information storage section 40 where connection information of the connection is stored. Start point connection destination information 52
Is data indicating whether the start point of the connection is connected to a terminal of a cell such as a function or an operand, or is connected to another connection. This is shown in FIG.
The start point or the end point of a connection, or both the start point and the end point, such as a polygonal connection between the terminal g of the cell 110 of the operand "D" and the terminal e of the cell 70 of the subtraction (-) function shown in FIG. Corresponds to the case where it is connected to another connection.

In the start point connection destination terminal information storage position 53 and the start point connection destination connection information storage position 54, the start point connection destination information 52 is stored.
The data is stored in one of them according to the data.
That is, when the connection destination of the connection start point is a terminal, the storage area where the terminal information of the connection destination terminal in the terminal information storage unit 30 is stored in the start point connection destination terminal information storage position 53. Is stored. On the other hand, when the connection destination of the start point of the connection is another connection, the connection information of the connection destination in the connection information storage unit 40 is stored in the start connection destination connection information storage position 54. Data indicating the head position of the storage area is stored.

In the same manner as in the case of the above-mentioned start point, data is stored in one of the end point connection destination information storage position 53 and the end point connection connection information storage position 54 in accordance with the data of the end point connection destination information 52. You.

That is, when the connection destination of the end point of the connection is a terminal, the terminal connection destination terminal information storage position 53
In the terminal information storage unit 30, data indicating the head position of the storage area in which the information of the connection destination terminal is stored is stored. On the other hand, if the connection destination of the connection destination is another connection, the connection information of the connection of the connection destination is stored in the connection information storage unit 40 in the connection information storage location 54 of the connection destination. Data indicating the head position of the area is stored.

FIG. 3 is a flowchart for explaining the operation of the program input support process of the programming device 10. Here, it is assumed that a program having the same content as the program created in FIG. 6 is created, and a display example of the illustrated representation is shown in FIG.

Hereinafter, description will be made with reference to FIGS.
In FIG. 3, first, when an operation of selecting / arranging an addition (+) function and a subtraction (−) function from an instruction group is performed by an operator or the like, cell and terminal information (cell information, cell information, Storage areas for storing the terminal information) are secured in the cell information storage unit 20 and the terminal information storage unit 30, respectively, and the information shown in FIGS. 2A and 2B is stored in the secured storage areas. (Step S1). That is, the addition (+) is added to the storage area secured in the cell information storage unit 20.
Cell information (cell type 21 to cell height 2)
9) and cell information (cell type 21 to cell height 29) of the cell of the subtraction (-) function is stored. Further, in the storage area secured in the terminal information storage unit 30, each terminal information (input / output division 31 to connection management information position 36) of the three terminals of the cell of the addition (+) function and the subtraction (-) The terminal information of each of the three terminals (input / output division 31 to connection management information position 36) of the function cell is stored.

Then, the addition (+) and the subtraction (-) stored in the cell information storage section 20 and the terminal information storage section 30 are performed.
On the display screen, for example, as shown in FIG. 4A, addition (+),
The cells 60 and 70 and the terminals a to f of the respective functions of the subtraction (-) are displayed (step S2).

Next, an operand description part (operand "A", "B", "C") is obtained from an instruction group by an operator or the like.
Is performed and an operation of arranging the cells of the selected operand near the terminals of the cells of the corresponding (to be connected) functions is performed, the storage area for storing the information of the cells and terminals of each operand To the cell information storage unit 2
0, the information is secured in the terminal information storage unit 30, and the information shown in FIGS. 2A and 2B is stored in the secured storage areas (step S3).

Each of the operands “A”, “B”, and “C” stored in the cell information storage unit 20 and the terminal information storage unit 30, respectively.
Based on the cell information and the terminal information of the cell "C", for example, as shown in FIG. 4B, the cells 80, 90, 100 of the operands "A", "B", "C" are displayed on the display screen. Is displayed (step S4).

Next, when an operator or the like selects "straight line (horizontal line or vertical line)" or "diagonal line" from the command group and designates a start point and an end point, the start point and the end point are designated. (Step S)
5). Then, the terminal information storage unit 30 is searched to determine whether the specified positions of the start point and the end point are on the terminal (step S6). This determination is based on the start point and end point (X,
Y) The coordinates are compared with the data of the terminal XY coordinates 35 of each terminal stored in the terminal information storage unit 30, and it is determined whether there is matching data.

If it is determined that the start point and end point of the “straight line” or “diagonal line” are on the terminal (step S
Then, it is determined whether or not the terminal at the start point and the terminal at the end point form a combination of input / output (step S7). This is because, in the terminal information storage unit 30, one of the input / output sections 31 of the terminal located at the start point and the data of the input / output section 31 of the terminal located at the end point is referred to. To determine whether the other is output.

If it is determined that the terminal at the position where the starting point and the ending point of the "straight line" or "diagonal line" are designated is a combination of input / output (step S7, YES),
Assuming that the correct connection has been specified, the data relating to the specified connection is stored in the connection information storage unit 40 and the connection management information storage unit 50. In addition, the connection management information position 36 of each terminal at the start point and end point positions in the terminal information storage unit 30.
Then, data indicating the head position of the storage area in which the current data is stored in the connection management information storage unit 50 is written (step S8).

Then, based on the data stored in the connection information storage section 40, a "straight line" or "diagonal line" connection is displayed on the display screen (step S9). Finally, it is determined whether the connection work has been completed or another connection is to be performed (step S10). If another connection work is to be performed (step S10, NO), the steps S5 to S9 are performed. Repeat the process.

Cells 80 and 9 of operands "A" and "B"
Connections 201 and 202 between the output terminals h and i of 0 and the respective input terminals a and b of the cell 60 of the addition (+) function, the output terminals c of the cell 60 of the addition (+) function and the subtraction (−) function. Connection 301 between input terminal d of function cell 70, output terminal f of subtraction (-) function cell 70 and cell 1 of operand "C"
The connection 401 with the input terminal j of “00” is displayed as shown in FIG. 4C as a result of selecting “straight line (horizontal line)” from the instruction group by the operator or the like and performing the above processing.

The connection 501 between the output terminal g of the cell 110 of the operand "D" and the input terminal e of the cell 70 of the subtraction (-) function cannot be made by a single straight line (horizontal line). ) Multiple straight lines (horizontal and vertical)
It is necessary to perform a complicated operation of connecting and connecting in a broken line. In such a case, the operator or the like selects the “diagonal line” from the instruction group and performs the above processing, thereby connecting the terminals “ge” with the diagonal line 501 as shown in FIG. Is displayed.

The present invention is not limited to the above embodiment. Even if a straight line or an oblique line is not selected, the two terminals may be automatically connected by a straight line or an oblique line according to the positional relationship between the designated two terminals.

By the way, the programming device of the PC is as follows.
In addition to a specially developed device, there is a device that uses application software (software stored in a storage medium such as a floppy disk) that realizes a PC programming function using a general personal computer as a tool body. Further, even in the device developed exclusively for the above, the application software may be exchanged using a floppy disk or the like. Therefore, the present invention is not limited to the main body of the programming device and the method of supporting program creation in the programming device, but also has a computer-readable record for causing a computer to perform the functions of the above-described embodiments of the present invention when used by the computer. It can also be configured as a medium (storage medium).

In this case, the “recording medium” includes, for example, FIG.
As shown in FIG.
0, floppy disk 720 (or MO, DV
D, a removable hard disk, etc.), a storage means (not shown) in an external device 600 (such as a server), or an information processing device 8
00 storage device 830 (RAM / ROM
Or a hard disk).

In FIG. 5, a program (data) 600a stored in a storage means (not shown) in an external device 600 on the program (data) provider side is a line such as a public line, a dedicated line, an interface, or the like. The application program of the present invention is loaded into the storage device 830 in the main body 810 of the information processing device 800 on the side of the recipient via the application program 900 and executed.

The CD-ROM 710, the floppy disk 720 and the like are stored in the main body 810 of the information processing apparatus 800.
Drive 82 provided (or connected) to the
0, the program (program (data) 710) stored in these portable storage media 700
a, the program (data) 720a) is read (loaded into the storage device 830) by the medium drive device 820 and executed.

The device and the like developed exclusively for the above are ROM
Since the program may be changed by replacement, the portable storage medium includes a ROM.

[0064]

As described above in detail, according to the programming device of the present invention, the input / output combination of both terminals can be determined by simply designating the positions of both terminals to be connected (as the start point and the end point). Is automatically checked, and if the combination is correct, the two terminals are automatically connected, and furthermore, the two terminals can be connected diagonally according to the arrangement of the two terminals. Therefore, the processing load of the operation of the operator or the like is reduced, and the program creation based on the FB diagram can be efficiently performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a programming device according to an embodiment.

FIG. 2 is a diagram illustrating a data configuration of each information storage unit.

FIG. 3 is a flowchart illustrating an operation of a program input support process.

FIG. 4 is a diagram showing an example of program creation / display using an FB diagram.

FIG. 5 is a diagram illustrating an example of a recording medium (storage medium).

FIG. 6 is a diagram showing an example of a conventional FB diagram for creating / displaying a program.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CPU 2 Input part 3 RAM 3-1 Cell information storage part 3-2 Terminal information storage part 3-3 Connection information storage part 3-4 Connection management information storage part 4 Storage part 5 Display part 6 Medium drive device 7 Portable storage Medium 8 Communication unit 10 Programming device 11 PC 20 Cell information storage unit 21 Cell type 22 Cell name 23 Number of inputs 24 Input terminal information storage start position 25 Output number 26 Output terminal information storage start position 27 Cell XY coordinates 28 Cell width 29 Cell height S 30 Terminal information storage unit 31 Input / output classification 32 Applicable cell information storage position 33 Previous terminal information storage position 34 Next terminal information storage position 35 Terminal XY coordinate 36 Applicable connection management information storage position 40 Connection information storage unit 41 Connection start XY position 42 Wiring end XY position 43 Wiring management information position 50 Wiring management information storage unit 51 Wiring information storage position 52 Point connection destination information 53 Start point connection destination terminal information storage position 54 Start point connection destination connection information storage position 55 End point connection destination information 56 End point connection destination terminal information storage position 57 End point connection destination connection information storage position 60 Addition (+) function cell 70 Cell of subtraction (-) function 80 Cell of operand "A" 90 Cell of operand "B" 100 Cell of operand "C" 201, 202, 301, 401 Connection (straight line) 501 Connection (diagonal line) 600 External Device 600a Program (data) 700 Portable storage medium 710 CD-ROM 710a Program (data) 720 Floppy disk 720a Program (data) 800 Information processing device 810 Main body 820 Medium drive 830 Storage device 830a Program (data) 900 Line

Claims (4)

[Claims] 1. A programming device for creating a program for operating a programmable controller in a graphical representation on a display screen by connecting graphic symbols and terminals of the graphic symbols, the first and second displayed programs being displayed. Designating means for designating the start and end points of the connection in order to connect the terminals of the graphic symbol; and the first and second positions existing at the start and end positions of the connection designated by the designating means Detecting means for detecting a terminal of a graphic symbol; determining means for determining whether each terminal is a combination of input / output based on terminal information of each terminal detected by the detecting means; A connection means for connecting between the terminals when the means determines that each terminal is a combination of input / output. 2. The programming device according to claim 1, wherein said connection means connects the terminals with a horizontal line, a vertical line, or an oblique line as specified. 3. A connection method for connecting terminals of first and second graphic symbols displayed on a screen in a programming device for creating a program for operating a programmable controller on a display screen in a graphical representation, the method comprising: Detecting the terminals of the first and second graphic symbols present at the start point and the end point of the connection, and determining whether or not each terminal is a combination of input / output based on the detected terminal information of each terminal. Determining whether each of the terminals is a combination of input / output, and connecting the terminals. 4. A function for designating a start point position and an end point position of a connection when the program for operating a programmable controller is executed in an information processing device for creating a graphical representation, and a program which exists at the designated start point position and end point position. A function of detecting terminals of the first and second graphic symbols to be performed, a function of determining whether or not each terminal is a combination of input / output based on the detected terminal information of each terminal; When the terminal is a combination of input / output, a function of connecting the start point and the end point, and a program for realizing the following are recorded in a format readable by the information processing apparatus.