CN115050243A

CN115050243A - Method for establishing PLC cloud experiment platform based on S7 protocol

Info

Publication number: CN115050243A
Application number: CN202111369734.3A
Authority: CN
Inventors: 孙万通; 许中林; 陈众
Original assignee: Changsha University of Science and Technology
Current assignee: Changsha University of Science and Technology
Priority date: 2021-11-16
Filing date: 2021-11-16
Publication date: 2022-09-13

Abstract

The invention discloses a method for combining teaching models, experimental models, internet + education, big data and other emerging technologies, constructing a virtual control object scene on a cloud server, and simultaneously implementing data exchange between the virtual scene and PLC development software by using a soft PLC middleware aiming at common PLC development software. The method establishes data exchange between common PLC programming software and a virtual control object scene, realizes that the PLC experiment is not limited by time, field, equipment and the like, better develops on-line experiment teaching about the PLC, and achieves the aim of integrating the in-class and out-of-class experiments and not isolating theoretical links from practical links.

Description

Method for establishing PLC cloud experiment platform based on S7 protocol

Technical Field

The invention relates to the technical field of experiment teaching, in particular to a method for building a PLC virtual simulation experiment cloud platform by using soft middleware.

Background

Programmable Logic Controllers (PLCs) have found wide applications in various fields of industrial control due to their high reliability, wide application, powerful functionality, and convenient use. At the present stage, PLC courses are set up in each of the universities and colleges in China in a dispute, the courses are professional compulsory courses for students in the professions of electrical, automation and machinery, teaching contents mainly include PLC basic knowledge and PLC operation and use, and the proportion of experiment teaching is large and the practice is very strong. The professional student can be competent for post-employment work or effectively carry out next research learning only through a large amount of practice teaching and relevant programming skills in a skillful mastery area.

At present, PLC control experiment teaching in colleges and universities faces practical problems of high investment cost, large occupied area, simple and few experiment contents, fixed experiment duration and the like. The experimental equipment is processed by using a virtual simulation technology, data interaction between a virtual control object and PLC development software is performed by using a soft middle part, the problems can be better solved by building an experimental cloud platform, and the experimental cloud platform can also respond to a national call, so that class halt and learning avoidance can be realized, and online experiments are performed.

Disclosure of Invention

Aiming at the defects of the existing PLC on-line experiment teaching, the invention aims to provide a method for realizing data interaction between a virtual control object and PLC development software. Meanwhile, a method for connecting a virtual control object with a webpage when a PLC cloud platform is built and an anti-cheating question bank of a PLC experiment are also provided.

In order to achieve the purpose, the invention provides a method for communicating with PLC development software based on an S7 protocol and forwarding the acquired data to a background server.

The S7 message received by the TCP protocol by using the soft intermediate method comprises three parts, namely TPKT, COTP and S7 PDU, wherein the S7 PDU is a part which actually acts. And S7 PDU is divided into HEADER, PARAMETER and DATA. And enabling the virtual control object to exchange data with the network background.

The method for building the virtual simulation object comprises the steps of utilizing modeling software to build a model of the experimental object, utilizing 3DMAX to carry out required format conversion, exporting a suffix FBX file, and then utilizing Unity3D to package animation into a WEBGL packet embedded webpage.

The anti-cheating question bank is used for acquiring corresponding questions according to the question ids, then users answer the questions according to the acquired questions, the answers are uploaded to the background to be intelligently checked, and then the webpage is used for acquiring judgment results to be displayed.

Drawings

Fig. 1 is a soft intermediate principle schematic.

FIG. 2 is a flow chart of web page 3D animation development;

Detailed Description

The cloud platform constructed by the method realizes online teaching of PLC experiments, and the method comprises the following steps:

1. building a 3D animation model, modeling by using modeling software, performing required format conversion by using 3DMAX software, and performing logic writing by using Unity3D, so that a webpage can load Unity3D animation and obtain an instance; after receiving the background information, the webpage sends corresponding data to the Unity to ensure that the animation is matched with the experimental data; carrying out corresponding animation after the Unity3D receives the information;

2. establishing a soft middleware to perform data interaction between a virtual control object and PLC development software, wherein the interaction is characterized in that the data of the PLC development software can control an animation model established on a webpage, and the action of the animation model is directly fed back to the soft middleware so as to control a writing program of the PLC development software;

3. based on different virtual control objects, a random question appears by utilizing an anti-cheating question library, and the question comprises different control logics;

4. the student writes a program on the PLC development software to realize control logic;

5. and the cloud experiment platform completes state calculation in a mathematical model according to the obtained control information and judges whether the control logic is correct or incorrect. And feeding back the data to obtain an experimental result.

It will be understood by those skilled in the art that the foregoing is only an exemplary embodiment of the present invention, and is not intended to limit the invention to the particular forms disclosed, since various modifications, substitutions and improvements within the spirit and scope of the invention are possible and within the scope of the appended claims.

Claims

1. A method for establishing a PLC cloud experiment platform based on an S7 protocol is characterized by comprising the following steps:

1) the cloud experiment platform establishes the 2D/3D model in a network page according to the method, presents random control logic based on an anti-cheating question bank, controls the virtual simulation experiment model by using a program written by PLC programming software and counts control results.

2) And the soft middleware reads the control data from the PLC programming software and sends the control data to the virtual control object, and meanwhile, the control result of the virtual object can be fed back to the soft middleware, so that the actual data interaction condition can be observed.

2. The cloud platform of claim 1, wherein the data flow is characterized by:

1) the cloud experiment platform is deployed in a wide area network, and the soft middleware is connected with the virtual control object and the PLC programming software is connected with the soft middleware through a TCP/IP communication protocol;

2) the 2D/3D model is built in a network page, modeling is carried out by using modeling software, required format conversion is carried out by using 3DMAX, an FBX file with a suffix is exported, and animation is packaged into a WEBGL package embedded webpage by using Unity 3D.

3) The random control logic utilizes the anti-cheating question bank to compile different PLC virtual control objects, so that different students can compile different logics to prevent cheating.

3. The cloud experiment platform of claim 1, wherein the experiment process is characterized in that:

1) the trainee observes the control logic needed by the virtual control object on the webpage;

2) the student compiles a logic program on the PLC programming software;

3) opening the soft middleware, and reading the compiled program by the PLC soft middleware;

4) and opening a webpage, connecting a soft middleware in the webpage, carrying out data interaction, feeding back data information to the soft middleware, judging whether the compiling program is correct or incorrect, counting experimental results, and feeding back.