JPH0643913A - Interlock adding device for ladder diagram - Google Patents

Abstract

(57) [Abstract] [Purpose] Interlock information can be automatically added to the ladder diagram, facilitating the development of the sequence program by the ladder diagram and improving the reliability of the program. An interlock addition device is provided. [Structure] A ladder diagram from a ladder diagram file 11 is analyzed by a ladder diagram analysis unit 12 to extract an output, and then the contents of an interlock file 13 storing formal interlock information are compared with a determination unit 14. By doing so, it is determined whether or not the output to which the interlock information is to be added, and the interlock information corresponding to the output is output to the output for which the interlock information is determined to be added by the interlock adding unit 15. It is added according to the interlock addition rule 16, and this is stored in the ladder diagram file 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ladder diagram interlock addition device used in a system for automatically generating and correcting a program by a ladder diagram.

[0002]

2. Description of the Related Art Recently, automatic sequence control by a computer has been widely adopted in production lines of various industrial products. A sequence program using a ladder diagram is mainly used for such sequence control by a computer. As is well known, the ladder diagram is a diagram in which input conditions and outputs corresponding thereto are arranged in a ladder shape, and represents the specifications of sequence control.

In sequence control, interlock is essential. The interlock is a constraint condition that prevents a transition to another operation or state until the completion of a certain operation or state. When using a ladder diagram for a sequence program, it is necessary to add interlock information to the ladder diagram as well. Therefore, conventionally, the programmer has interpreted the sequence control specifications and directly created a ladder diagram including interlocks based on the interpretation.

However, in such a method of manually adding a ladder diagram including an interlock, it takes time to develop a program, not only increases the development cost, but also causes an error because it is an artificial work. It is easy and the reliability of the program is reduced.

[0005]

As described above, in the conventional technique, when a ladder diagram is used in a sequence program, a method of manually creating a ladder diagram including an interlock is used, and therefore the time required for developing the program is increased. Therefore, there is a problem that the cost is increased and the program is apt to make an error and the reliability is poor.

The present invention can automatically add interlock information to a ladder diagram, reduce the time and cost required to develop a sequence program based on a ladder diagram, and improve the reliability of the program. It is an object of the present invention to provide an interlock addition device for a ladder diagram capable of performing the above.

[0007]

In order to solve the above problems, the present invention is a ladder diagram in which interlock information is added to a ladder diagram in which the relationship between the input condition and the output corresponding to the input condition is arranged in a ladder shape. In the interlock addition device of
The output in the ladder diagram before adding the interlock information is compared with the interlock information to determine the output to which the interlock information should be added, and the corresponding interlock information is automatically output for that output. Is added to.

That is, an apparatus for adding an interlock to a ladder diagram according to one aspect of the present invention includes an analyzing unit that analyzes the ladder diagram and extracts an output, an interlock storing unit that stores interlock information, Judgment means for comparing the contents of the interlock storage means with the output extracted by the analysis means to judge whether the output is an output to which interlock information should be added, and the interlock information is added by this judgment means. An interlock adding unit that reads the information of the interlock corresponding to the output from the interlock storage unit and adds the output to the output that is determined to be appropriate is provided.

According to another aspect of the present invention, there is provided a ladder diagram interlock adding device, which is a ladder diagram storing means for storing information of the ladder diagram before the interlock is added, and an interlock memory for storing information of the interlock. Means, a determination means for searching the output corresponding to the interlock information read from the interlock storage means from the ladder diagram storage means, and determining the output to which the interlock information should be added, and the determination means. And an interlock addition means for adding the interlock information read from the interlock storage means to the output.

[0010]

As described above, in the present invention, the interlock information is automatically added to the ladder diagram based on the formally described interlock information. Therefore, the time required for developing / correcting the sequence program using the ladder diagram can be shortened, the development cost can be reduced, and the reliability of the sequence program can be improved by reducing the errors in the program.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an interlock addition device for a ladder diagram according to an embodiment of the present invention. This interlock addition device is a ladder diagram file 11 which is a ladder diagram storage unit before adding interlock information, a ladder diagram analysis unit 12, an interlock file 13, which is an interlock storage unit, a determination unit 14, and an interlock addition unit 15. ,
It comprises an interlock addition rule 16 and a ladder diagram file 17 which is a ladder diagram storage means before adding interlock information. The ladder diagram file 11 stores the data of the ladder diagram before adding the interlock information.

The ladder diagram analysis unit 12 reads the data of the ladder diagram from the ladder diagram file 11 and analyzes it to extract the output in the ladder diagram, that is, the information about the coil. The interlock file 13 stores interlock information to be added to each coil in the ladder diagram, which is formally described in association with the coil name.

The determination unit 14 compares the coil information extracted by the ladder diagram analysis unit 12 with the interlock information from the interlock file 13, and determines whether the coil is a coil to which the interlock information should be added. Determine whether

According to the interlock addition rule 16, the interlock addition unit 15 selects the interlock for the coil which is judged by the judgment unit 14 to add the interlock information in the ladder diagram read from the ladder diagram file 11. Add information. The interlock addition rule 16 is
It stores rules that indicate how to add interlock information to a ladder diagram depending on the type of interlock. The ladder diagram file 17 stores the data of the ladder diagram after the interlock information is added by the interlock adding unit 15.

Next, the operation of the interlock addition device shown in FIG. 1 will be described with reference to the flowchart shown in FIG. First, it is assumed that the ladder diagram file 11 stores the data of the ladder diagram as shown in FIG. In this ladder diagram, the input conditions are the a contacts of multiple relays X000, X001,
, And outputs are represented by coils Y000, Y001, ..., and these are arranged in a ladder shape. Since the contact a is normally off, the coil Y000 is energized under the condition that X000 is turned on, for example.

The ladder diagram analysis unit 12 reads the ladder diagram shown in FIG. 3 from the ladder diagram file 11 and extracts information on the coils Y000, Y001, ... One by one from this ladder diagram (S11 to S14). That is, in S12, it is checked whether or not the ladder diagram read in S11 is finished, and if it is finished, the interlock addition process for the ladder diagram ends. In S13, it is checked whether or not the ladder diagram read in S11 includes a coil. If not, the process returns to S12. If it is determined that the coil is included in S13, it is extracted (S14).

When the coil is extracted in S14, the determination unit 14 determines the information of the coil and the interlock file 13
Compare the interlock information stored in (S1
5), further, the interlock information to be added to the coil extracted by the ladder diagram analysis unit 12 is the interlock file 1
3 is determined (S16), and the determination result is sent to the interlock addition unit 15.

FIG. 4 shows an example of the interlock information stored in the interlock file 13, in which coil names corresponding to the targets 1 and 2 related to the interlock,
This is a table in which the types of interlocks and the conditions (input conditions) for each interlock are associated with each other. The type of interlock is related to the interlock addition rule described later.

For example, in the starting interlock, when the a contact X000 in FIG. 4 is turned on, the coil Y000 in FIG. 4 which is the target 1 is energized on condition that the a contact X006 is turned on. It represents. The driving interlock is almost the same. The mutual exclusion interlock and the order interlock both define coil names corresponding to the two targets 1 and 2.

The interlock adding unit 15 receives the judgment result from the judging unit 14, and stores (that is, extracts) the interlock to be added to the coil extracted by the ladder diagram analyzing unit 12 in the interlock file 13. (If the coil name of the coil is used for one of the targets 1 and 2 in the interlock information of FIG. 4), the interlock information is read from the interlock file 13 and the interlock addition rule 16 is set. Ladder diagram file 11 according to the stored interlock addition rule
Add to the corresponding coil in the ladder diagram from (S1
7) and then returns to S12.

FIG. 5 shows an example of the interlock addition rule. (A) Start interlock, (b) Operation interlock, (c) Mutual exclusion interlock and (d).
The rules for each case of sequence interlock are shown.
The starting interlock is a condition that must be satisfied at the time of starting, and does not have to be satisfied when the vehicle is in an operating state. The driving interlock is a condition that must be satisfied during driving as well as during starting. "Conditions" in the starting interlock and the driving interlock are, for example, as shown on the right side of FIG.

The mutual exclusion interlock is a condition for preventing a specific state from occurring simultaneously among a plurality of devices. If one target (1 or 2) is a coil, the other target (2 or 1) is used. ) Is the b contact (normally on) of the relay with the coil.

The order interlock is a condition that limits the order of operations among a plurality of related devices. In this example, the coil of the target 1 is turned on earlier than the coil of the target 2.

FIG. 6 shows a ladder diagram after the interlock addition section 15 adds interlock information to the ladder diagram shown in FIG. 6, A is an interlock added by the starting interlock rule shown in FIG. 5A, B is an interlock added by the driving interlock rule shown in FIG. 5B, and C is FIG. 5C. ) Indicates an interlock added by the mutual exclusion interlock rule, and D indicates an interlock added by the order interlock rule shown in FIG. 5D. The ladder diagram data to which the interlock information is added in this way is stored in the ladder diagram file 17.

Next, the operation according to another embodiment of the present invention will be described with reference to FIG. The basic configuration of the interlock addition device itself is the same as that shown in FIG. In this embodiment, first, the determination unit 14 reads one target from the interlock file 13, and the coil that matches this target is passed through the ladder diagram analysis unit 12 to the ladder diagram file 1
The search is performed from 1 (S21 to S23).

That is, in S22, it is checked whether or not the interlock read from the interlock file 13 is finished. If it is finished, the interlock addition process for the ladder diagram stored in the ladder diagram file 11 is finished.
In step S23, the ladder diagram file 11 is searched for a coil that matches the target read in step S21. Then, it is checked whether or not there is a coil matching the target, and if not, the process returns to S21.

If there is a coil that matches the target in S24, the determination unit 14 notifies the interlock addition unit 15 of that fact. Upon receiving this notification, the interlock adding unit 15 adds the interlock information read from the interlock file 13 to the coil read from the ladder diagram file 11 in accordance with the interlock addition rule stored in the interlock addition rule 16. (S25), and then returns to S22.

Also in this embodiment, the same result as the previous embodiment can be obtained. Further, according to this embodiment, since only the coil that matches the interlock information (target) is searched, there is an advantage that the processing time required to add the interlock information is shortened.

[0029]

As described above, according to the present invention, the interlock information can be automatically added to the ladder diagram before the interlock information is added.
The time and cost required to develop a sequence program using a ladder diagram can be reduced, and unlike the case where a ladder diagram containing interlock information is created by conventional human-made work, errors are unlikely to occur in the program. The reliability of is significantly improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an interlock addition device for a ladder diagram according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of operations of the embodiment.

3 is a diagram showing an example of a ladder diagram stored in a ladder diagram file (before adding an interlock) in FIG. 1. FIG.

FIG. 4 is a diagram showing an example of the contents of an interlock file in FIG.

5 is a diagram showing an example of contents of an interlock addition rule in FIG.

6 is a diagram showing an example of a ladder diagram stored in a ladder diagram file (after interlock is added) in FIG. 1. FIG.

FIG. 7 is a flowchart showing a flow of operations according to another embodiment of the present invention.

[Explanation of symbols]

11 ... Ladder diagram file 12 ... Ladder diagram analysis unit 13 ... Interlock file 14 ... Judgment unit 15 ... Interlock addition unit 16 ... Interlock addition rule 17 ... Ladder diagram file

Claims (2)

[Claims] 1. A ladder diagram interlock adding device for adding interlock information to a ladder diagram in which a relationship between an input condition and an output corresponding to the input condition is arranged in a ladder.
Analyzing means for analyzing the ladder diagram to extract the output, interlock storing means for storing the interlock information, and comparing the contents of the interlock storing means with the output extracted by the analyzing means. Determination means for determining whether the output is an output to which interlock information should be added, and interlock information corresponding to the output with respect to the output determined by the determination means to add the interlock information And an interlock adding means for reading and adding from the interlock storage means. 2. A ladder diagram interlock adding apparatus for adding interlock information to a ladder diagram in which a relationship between an input condition and an output corresponding to the input condition is arranged in a ladder shape,
Corresponding to the ladder diagram storing means storing the information of the ladder diagram before the interlock is added, the interlock storing means storing the information of the interlock, and the interlock information read from the interlock storing means. Determining means for determining the output to be added with the interlock information by searching the output from the ladder diagram storing means, and the interlock read from the interlock storing means for the output determined by the determining means. An interlock adding device for a ladder diagram, comprising: an interlock adding means for adding information.