JPS61109105A - Sequence controller - Google Patents

Abstract

PURPOSE:To simplify an editing means and to improve the operability of a sequence controller by writing the executing conditions of each minor process in the form of algebra according to the end conditions of the process of the preceding process. CONSTITUTION:A sequence controller contains an upper device 8 consisting of a computer and an executing device 9 which executes each minor process indicated by the device 8. The device 8 contains a writing means 801 for the start conditions of those minor processes. Those conditions are written to a table set in a memory via a CRT802, etc. While an editing means 804 receives the contents of the means 801 and sends a command signal to the device 9. When a start signal is given, the execution of a minor process A, for example, is indicated to the device 9. Thus the device 9 reads said indication and starts the process A. Then the device 9 answers back an end signal when the execution is through with the process A. The procedure proceeds to the 2nd step. Hereafter the processes are carried out successively. Thus all processes re over with said answer-back of the end signal to complete a sequence.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a sequence control device that is realized by combining a plurality of small steps whose execution contents are defined in advance.

<Prior Art> It is assumed that a plant for manufacturing an existing product is composed of a plurality of small processes A, B, . . . N, and the execution content of each small process is specified. For example, as shown in Fig. 4, when a plurality of products are introduced and mixed in the K A -N process in the evening/drink 1, in the manual process, the products 3 in the weighing hopper 2 are
is injected into the tank 1 by operating the control valve 4, and in step (2), the fluid 5 is injected into the patch controller 6 by a constant set value SV by operating the control valve 7.

When executing multiple small steps with predetermined execution contents in an arbitrary order, the execution contents must be set in a translated form so that the equipment that executes each step can operate in the predetermined order. .

One of the conventional methods for realizing such water sprinkling is to first provide an execution device and create a sequence for executing each of the seven steps in this execution device. Then, the content that the execution device can operate (hereinafter referred to as a scheduler) is edited and set in an operable format by the higher-level device that manages and commands the process order.

In this method, in the execution device example, it is necessary to imagine all the schedulers corresponding to the product type and perform all operations and checks on them, and on the host device side, the execution device needs to be edited into a scheduler in a format that can be operated. This makes the process complicated.

<Problems to be Solved by the Invention> The object of the present invention is to realize a scheduler in a host device and a sequence control device that can be extremely simple and easy to edit.

Means for Solving Problems〉 The structural feature of the present invention is that the activation conditions of a plurality of small processes whose execution contents are specified in advance are entered in a table using pool algebraic expressions of the termination conditions of the preceding process. The present invention is characterized in that it includes an entry means for editing the start conditions based on the entry contents of this means, an editing means for editing the activation conditions based on the entry contents of this means, and an execution means for executing the contents of the above-mentioned sub-processes based on the output of this means.

Effect> Since the start condition of each process is expressed in the form of a pool algebra representation of the end condition of the previous process, the editing work can be realized by executing simple logical operations.

<Embodiment> An embodiment of the apparatus of the present invention will be described based on Broom 1 to FIG. 6. In the block diagram of FIG. 1, numeral 8 denotes a higher-level device constituted by a computer, and 9 denotes an execution device for executing each small process instructed by the higher-level device.

In the host device 8, 801 is an entry means for entering the starting conditions of the small process to be used, and CRT 802. The contents as shown in FIG. 2 are entered in a table provided in the memory via an interface means such as a keyboard 803.

There are 6 small steps A, B...F used in the example.
The starting conditions for each process A to F are as follows: A: Starts unconditionally according to an operator's command.

B: Starts when process A is completed.

C: Starts when the human process is completed.

D...Starts when step B or C is completed.

E...Start when the second layer of people is finished.

F...Starts when steps D and E are completed.

If the activation condition of each process is expressed by the termination condition of the preceding process, then if the activation condition of each process is expressed in pool algebra by adding a dash to the symbol of that process, the result will be as shown in Figure 2. This is the table contents. Since the engineer starts the process based on the operator's command, it is expressed as Jl.

Reference numeral 804 denotes an editing means, which receives the contents of the entry means 801 and sends a (b command signal) to the execution device 9 for executing each small step. FIG. 3 is an explanatory diagram of the operation of this editing means. First, in the first step (1), when there is a start signal from the operator's command, the start condition of A becomes 1, and the execution device #9 is instructed to execute the small process A.The execution device 9 reads this command and Start A, and when the execution is finished, answer back the end signal. With this answer back, the end condition A' of A is satisfied, proceed to the second step (2), and proceed to sub-process B.
.

The execution device 9 is instructed to execute C and E. The execution device reads this command, activates non-steps B, C, and E, and answers back an end signal when the execution of each step is completed. If there is an answer back indicating the end of the small step B or C, the end condition B' or C' is satisfied, so the process proceeds to the third step (3) and instructs the execution device 9 to execute the small step. The execution device reads this command, starts a small process, and when the execution is finished, answers back an end signal. With this answerback, the termination condition D' of D is satisfied, and if the termination condition E' of E is satisfied at this time, the process proceeds to the fourth step (4), and the execution device 9 is instructed to execute the small process F. The execution device accepts this command, starts the small process j'f:, and when the execution is finished, answers back the end signal. This answer back covers the whole process! This completes one sequence.

The interpretation of the logical formula format % entered in the table shown in Figure 2 is to, (In formula 21, when the left side is 1, the small process on the left side is started, and the termination condition on the right side is that the seventh step is completed. If we specify that it becomes 1 when (I
The expression ) can be logically operated by the OR gate IO, and the expression +2) can be very easily logically operated by the anchor 11, and the output of the anchor can be used to start the next process.

As explained above, according to the present invention, an extremely simple logic circuit can be created by writing the execution conditions of each sub-process into the table of the entry means using the pool algebra expression according to the termination condition of the preceding step. The execution device can be instructed to start each process through the means, the editing means can be greatly simplified, and the conventional complicated scheduler creation work can be eliminated. Therefore, the schedule history of the sequence controller is 1! !
It is possible to improve the operability of the device by allowing the operator on the user side to perform complex changing operations without specialized knowledge.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a table structure diagram showing an example of the contents of the entry means, FIG. 3 is a block diagram explaining the operation of the editing means, and FIG. FIG. 2 is an explanatory diagram of a sequence control device including a plurality of small steps. 8... Upper device, 801... Entry means, 804...
・Edition Figure 1 Figure 2

Claims (1)

[Claims] An entry means for entering the starting conditions of multiple small processes whose execution contents are specified in advance in a Boolean algebraic expression of the ending conditions of the previous step, and editing for editing the starting conditions based on the contents entered in this means. A sequence control device comprising a means and an execution means for executing the contents of the above-mentioned small steps based on the output of the means.