CN116095161A - Method, system and application for converting PLC data into JSON format - Google Patents

Abstract

The invention belongs to the technical field of communication, and discloses a method, system and application for converting PLC data into JSON format. The method includes: building and running a Node-RED platform operating environment for field device data collection and transmission; using OPC protocol to collect real-time data of PLC sub-stations; using OPC software to convert and release the collected real-time data; using Node The ‑RED platform receives the published data from the OPC software; uses the Node‑RED platform to convert the received published data into JSON format. The invention uses the computer Node-RED platform to realize the conversion of traditional PLC data in the industrial automation industry into computer JSON format language, and is suitable for intelligent information projects such as industrial Internet of Things, big data, and cloud platforms.

Description

A method, system and application for converting PLC data into JSON format

technical field

The invention belongs to the technical field of communication, and in particular relates to a method, system and application for converting PLC data into JSON format.

Background technique

Digital twin technology and Internet of Things technology are popular directions of development in recent years. Digital factories need the support of a large amount of data, and industrial data is mainly PLC data. Data conversion and transmission require IT (Internet Technology, Internet technology) technicians to use Visual Studio software (application development software for Windows platform) writes source code to realize functions, the development cycle is long, and the IT technology threshold required is high. Solid C (a programming language), C++ (a programming language) or Java is required (a programming language) and other computer language foundations, while automatic control engineers mostly focus on the research of logic control, mainly using software, which is not suitable for software development, and more often, for a certain company The software written by PLC manufacturers cannot be applied to other PLC manufacturers. At this time, it will take time and experience to rewrite the corresponding software, resulting in repeated development, wasting time and experience, and the efficiency is too low.

The combination of Node-RED platform technology and OPC software perfectly solves the above problems. The OPC protocol is an international general technical protocol with a certain degree of openness. It can read the PLC data of various manufacturers and forward the data. . Node-RED platform technology is a programming tool for connecting hardware devices, APIs, and online services together in new and interesting ways. It provides a browser-based editor that makes it easy to wire streams together using various nodes in the edit panel and deploy it to its runtime with a single click. Node-RED can be installed locally and access its visual layout interface through a browser. Secondly, you can also use a rich text editor to create JavaScript in the editor (a lightweight, interpreted or just-in-time compilation with function priority) programming language) functions, built-in libraries also allow saving useful functions, templates or processes for re-use, and most importantly Node-RED technology is open source.

With the advent of Industry 4.0, the traditional automation industry can no longer fully adapt to the development of new technologies. Traditional industrial control technology needs to be combined with IT technology to achieve intelligence, such as digital twin technology and smart factories. The Internet of Things technology is advancing, and there are many IoT cloud platforms to choose from, but the key is the channel or form of data connection. Traditional industrial control is mainly based on PLC. By reading the PLC data, the host computer software can implement data monitoring or control actions on the control objects. However, there are many PLC manufacturers, and the data formats of each PLC manufacturer are different. If you want to To carry out the data connection between the cloud platform and the PLC, it is necessary to solve the problem of inconsistency in the data format, and at the same time ensure the security and real-time performance of the data. OPC software can well solve the problem of data format between various PLC manufacturers, but the data released by OPC software cannot be directly connected to the cloud platform, which requires protocol conversion.

JSON is a lightweight data exchange format, and it is a widely used computer language in the IT technology industry. At the same time, many cloud platforms, such as Alibaba Cloud, Tencent Cloud, Baidu Cloud, etc., all support the language in JSON format for data transmission. The cloud platform relies on the accumulation of data to analyze, monitor, and utilize data, and the analyzed data generates reports or data early warnings.

Through the above analysis, the problems and defects in the prior art are:

(1) In the existing communication protocols in the field of industrial automation, the efficiency of data analysis, monitoring and utilization is low, and abnormal data cannot be effectively displayed for early warning.

(2) In the prior art, centralized monitoring of products from different manufacturers is not effective, requiring a lot of individual monitoring of different monitoring devices, resulting in high cost, and the accuracy of monitoring in the prior art is low.

Contents of the invention

In order to overcome the problems existing in the related technology, the disclosed embodiment of the present invention provides a kind of utilization Node-RED platform (based on the operating environment built by Javascript language) to realize PLC (Programmable Logic Controller, programmable logic controller) data conversion to JSON format (JavaScript Object Notation, a lightweight data exchange format) method, system and application.

Described technical scheme is as follows: Utilize Node-RED to realize the method that PLC data is converted into JSON form, is applied to information data processing terminal, and this method comprises the following steps:

S1, build and run the Node-RED platform operating environment for field device data collection and transmission;

S2, using the OPC protocol to collect real-time data of the PLC sub-station;

S3, using OPC software to convert and publish the real-time data collected in step S2;

S4, using the Node-RED platform to receive the release data of the OPC software;

S5, use the Node-RED platform to convert the received published data into JSON format, and use the data debugging node that comes with the Node-RED platform to test the converted data.

In step S1, the field devices include: one or more of PLC devices, flow meters, pressure gauges, and temperature gauges.

In step S1, build the Node-RED platform operating environment for field device data collection and transmission, and run it specifically includes the following steps:

(1) Install the Node-RED platform operating environment:

①Search and download the Node.msi software installation package;

② Install the software on the Node.msi software installation package;

③ Open the command prompt of the Windows system with administrator privileges;

④Copy the code npm config set registry http://registry.npmmirror.com into the input box and run the code;

⑤ Copy the code npm install-g--unsafe-perm node-red pm2pm2-windows-startuppm2-windows-service into the input box and run the code;

(2) Use the CMD command prompt to run the Node-RED platform;

① Open the command prompt of the Windows system;

②Copy the code C:\Users\Administrator\AppData\Roaming\npm\node-red.cmd into the input box and press Enter to run the code.

In step S2, utilizing the OPC protocol to collect the real-time data of the PLC sub-station includes the following steps:

Step 1, establish a data collection channel;

Step 2, create new PLC data in the newly created data channel;

Step 3, test the correctness of the data.

In step S3, using the OPC software to convert and publish the data includes the following steps:

The OPC software converts the collected PLC data into an MQTT service through the IoT Gateway for external release.

Another object of the present invention is to provide a kind of method that utilizes Node-RED to realize that PLC data is converted into JSON format and utilize Node-RED to realize that PLC data is converted into JSON format system, described utilize Node-RED to realize PLC data conversion Formatting systems for JSON include:

The language operating environment building module is used to build the Node-RED platform operating environment for field device data collection and transmission, and run it;

The real-time data acquisition module is used to collect the real-time data of the PLC substation using the OPC protocol;

The data conversion module is used to convert and release data by using OPC software;

Published data receiving module, used to receive the published data of OPC software by using the Node-RED platform;

The format conversion module is used to convert the received data into JSON format using the Node-RED platform.

Another object of the present invention is to provide a program storage medium for receiving user input, and the stored computer program enables electronic equipment to execute the method for converting PLC data into JSON format using Node-RED.

Another object of the present invention is to provide a computer device, the computer device includes a memory and a processor, the memory stores a computer program, when the computer program is executed by the processor, the processor executes the Describe the method of using Node-RED to convert PLC data into JSON format.

Another object of the present invention is to provide a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the processor performs the conversion of PLC data into JSON format using Node-RED. Methods.

Another object of the present invention is to provide a centralized monitoring device for data information in the chemical industry and metallurgical industry, which implements the method for converting PLC data into JSON format using Node-RED.

In combination with all the above-mentioned technical solutions, the advantages and positive effects of the present invention are:

First, in view of the technical problems existing in the above-mentioned prior art and the difficulty of solving the problems, closely combine the technical solution to be protected in the present invention and the results and data in the research and development process, etc., to analyze in detail how the technical solution of the present invention solves it Technical problems, some creative technical effects brought after solving the problems, are specifically described as follows: The present invention uses the computer Node-RED platform to realize the conversion of traditional PLC data in the industrial automation industry into computer JSON format language, which is suitable for industrial Internet of Things, Smart information projects such as big data and cloud platforms.

Second, regarding the technical solution as a whole or from the perspective of products, the technical effects and advantages of the technical solution to be protected by the present invention are specifically described as follows: the present invention can connect products of different manufacturers to IT networks simply and reliably, Realize the functions of centralized monitoring and decentralized control on the web page of the system. In the traditional industrial control industry, OPC software can collect almost all brands of PLC equipment and instrumentation equipment. It has laid a solid foundation for data collection for traditional industrial intelligence information construction and digital twin factory technology, so as to facilitate subsequent data statistics and data analysis.

Third, as the auxiliary evidence of the inventiveness of the claims of the present invention, it is also reflected in the following important aspects: the present invention fills the technical gap of using the web page to read industrial PLC data in the field of IT technology, and the present invention solves the problem of PLC data data Format is converted into the technical problem of JSON data format, and the present invention overcomes the technical prejudice that IT technology and OT (OperatorTechnology, industrial site technology) technology cannot be well integrated.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description serve to explain the principles of the disclosure;

Fig. 1 is the method flow diagram that utilizes Node-RED to realize that PLC data is converted into JSON format provided by the embodiment of the present invention;

Fig. 2 is that the embodiment of the present invention provides and utilizes the OPC protocol to collect the real-time data flowchart of PLC substation;

Fig. 3 is the schematic diagram of utilizing Node-RED to realize the conversion of PLC data into JSON format system provided by the embodiment of the present invention;

Fig. 4 is an effect diagram of the real-time online display of production data of the smart water plant visualization technology implemented by the method of the present invention provided by the embodiment of the present invention;

In the figure: 1. Operating environment building module; 2. Real-time data acquisition module; 3. Data conversion module; 4. Release data receiving module; 5. Format conversion module.

Detailed ways

In order to make the above objects, features and advantages of the present invention more comprehensible, specific implementations of the present invention will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

1. Example of explanation:

Example 1

As shown in Figure 1, the method for utilizing Node-RED to convert PLC data into JSON format provided by the embodiment of the present invention is applied to an information data processing terminal and includes the following steps:

S1, build and run the Node-RED platform operating environment for field device data collection and transmission;

S2, using the OPC protocol (OLE for Process Control, a series of standard and common specifications jointly formulated by industry suppliers, end users and software developers) to collect real-time data of PLC substations;

S3, using OPC software to convert and publish the real-time data collected in step S2;

S4, using the Node-RED platform to receive the release data of the OPC software;

S5, use the Node-RED platform to convert the received published data into JSON format; and use the data debugging node that comes with the Node-RED platform to test the converted data to ensure the accuracy of the data after format conversion.

Exemplarily, in step S1, it includes: building and running a Node-RED platform operating environment for field device data collection and transmission. Field devices include flow meters, pressure gauges, and temperature gauges.

In the embodiment of the present invention, the specific implementation steps of S4 and S5 are as follows:

If the Node-RED platform is installed and running successfully, enter 127.0.0.1:1880 in the address bar of the browser and press Enter to enter the Node-RED platform configuration interface;

Select the MQTT in node (MQTT service receiving node) from the nodes on the left sidebar of the page, drag it to the process interface, and set its parameters. A new mqtt-broker (message queue server) node needs to be added. The server fills in the IP address (Internet Protocol Address) of the computer where the OPC software is located, the default port number, the theme name fills in IoTgateway, the output option selection: string, and click the Finish button;

Select the JSON node from the nodes on the left sidebar of the page, drag it into the process interface, and set its parameters, select the operation option to convert JSON string to object, and then set the "Format JSON String" option below Check it and click the Finish button;

Select the debug node (test node) from the nodes on the left sidebar of the page, drag it to the process interface, and set its parameters, check the "Node Status" option of the target parameter, and click the Finish button;

At this time, there are three nodes in the process interface, which are IoTgateway, JSON, and Debug. Connect the three nodes in turn with connecting lines, and then click the deployment button in the upper right corner. At this time, the Node-RED platform can follow the deployment process. Receive the data, convert the data format into JSON format through the JSON node, and finally see the display of real-time data through the Debug node, so as to verify the accuracy of the data, and the setting of this process is over.

Example 2

Based on the method of using Node-RED to convert PLC data into JSON format provided by Embodiment 1, further, step S101 builds the operating environment of the Node-RED platform, and runs:

(1) installation

Use cmd to run in administrator mode

npm config set registry http://registry.npmmirror.com

npm install --g --unsafe-perm node-red pm2pm2-windows-startup pm2-windows-service;

(2) run

C:\Users\Administrator\AppData\Roaming\npm\node-red.cmd

or

pm2

start C:\Users\Administrator\AppData\Roaming\npm\node_modules\node-red\red.js.

Specifically include:

(1) Install the Node-RED platform operating environment:

①First search and download the Node.msi (Windows platform application program name) software installation package, open source software does not have infringement problems.

② On the Node.msi software installation package, right-click to run with administrator privileges to install the software.

③ Open the command prompt of the Windows system with administrator privileges.

④ Copy the code npm config set registry http://registry.npmmirror.com (Windows platform standard code) to the input box and press Enter to run the code.

⑤ Copy the code npm install-g--unsafe-perm node-red pm2pm2-windows-startuppm2-windows-service (Windows platform standard code) to the input box and press Enter to run the code.

(2) Use the CMD (Command Prompt, command prompt) command prompt to run the Node-RED platform

① Open the command prompt of the Windows system with administrator privileges.

② Copy the code C:\Users\Administrator\AppData\Roaming\npm\node-red.cmd (Windows platform standard code) to the input box and press Enter to run the code.

Example 3

Based on the method of utilizing Node-RED to realize PLC data conversion to JSON format provided by embodiment 1, further, as shown in Figure 2, step S102 utilizes the OPC protocol to collect the real-time data of PLC sub-stations and includes the following steps:

S201, establishing a data collection channel;

The specific process is as follows:

Open the OPC software, and click Add Channel under the connectivity of the project tree on the right;

Select the channel type, you can choose different channel types according to the brand of PLC, click next after the selection is completed;

Specify a name for the newly created channel, and click Next when finished;

The virtual network settings and the number of transactions per cycle option remain unchanged by default, click Next;

Network adapter Select the network card in the same network segment as the PLC, and click Next after completion;

The optimization method and duty cycle options remain unchanged by default, click Next;

The floating-point value option remains unchanged by default, click Next;

Socket utilization, maximum number of sockets per device, port, IP protocol and other options remain unchanged by default, click Next;

This page is an overview of the parameters just set. If there is no problem, click the Finish button, and the data acquisition channel is established.

S202, creating new PLC data in the newly created data channel;

The specific process is as follows:

Click Add Device under the newly created channel in step S201;

Specify a name for the newly created device, and click Next when finished;

Select the communication model according to the communication type of the device to be connected, and click Next after completion;

Set the site or node of the device that needs to be connected, such as the IP address of the PLC site, etc.;

The initial update options of scan mode and cache remain unchanged by default, click Next;

Connection timeout, request timeout, number of attempts before timeout, delay between requests and other options remain unchanged by default, click Next;

The downgrade option on failure remains unchanged by default, click Next;

When the device is started, the default options for repeat flags, allow automatically generated subgroups, etc. remain unchanged, click Next;

Port, IP protocol, close socket after timeout and other options remain unchanged by default, click Next;

The zero-based addressing, zero-based bit addressing, holding register bit write, Modbus (Modbus protocol, serial communication protocol) function 06, Modbus function 05 and other options remain unchanged by default, click Next;

The Modbus byte order option is properly selected to enable or disable according to the data characteristics of the PLC substation, and the first word sorting is low. According to the data characteristics of the PLC substation, it is properly selected whether to enable the first word sorting. The options are the same as the option that the first word is sorted as low, and the rest of the options remain unchanged by default, click Next;

The output coil, input coil, internal register, holding register, block read string and other options remain unchanged by default, click Next;

This page is an overview of the parameters just set. If there is no problem, click the Finish button, and the connection between the OPC software and the PLC substation has been established.

On the main page of the OPC software, right-click in the blank space of the tag name dialog box, create a new tag, fill in the tag name and address, select the data type of the address to be read, click OK, and the PLC data is created.

S203, testing the correctness of the data.

Example 4

Based on the method of utilizing Node-RED to realize the conversion of PLC data into JSON format provided by embodiment 1, further, step S103 utilizes OPC software to convert and release data including the following steps:

OPC software has the function of IoT Gateway (IoT, Internet of things, that is, Internet of Things, Gateway, gateway, the full name can be interpreted as: Internet of Things data sending and receiving function), which can convert the collected PLC data into MQTT service (Message Queuing Telemetry Transport , Message Queue Telemetry Transmission) for external publishing

The specific process is as follows:

Open the OPC software, and click Add Agent under the IoT Gateway option in the project tree on the right;

In the newly opened New Agent (new agent node) dialog box, specify a name for Agent (agent node), select MQTT Client (MQTT message queue client) as the type, and click Next after the setting is complete;

Set the MQTT Broker (MQTT message queue server) parameters in the new setting interface, fill in the IP address of the local network card in the URL parameter (uniform resource locator, and the uniform resource locator system), and keep the port number unchanged. The Topic (topic) parameter is to specify a name for this MQTT Broker, which will be used when the Node-RED platform collects data later. The parameters in Publish (data publishing parameters) can be defaulted, and click Next after the setting is complete;

Set the Credentials parameter (communication certificate parameter) in the new setting interface. The Client ID (client number) is to specify a name for this Credentials. The Username (username) and Password (password) parameters can be used according to project requirements. , if it is set, it will be used when the Node-RED platform collects data later. After the setting is complete, click Finish to complete the establishment of the MQTT data publishing channel;

In the newly created Agent, click Add items (add a new label), select the data to be published in the opened tag browser, click the Apply button below, and the IoT Item parameter (parameter of the new label) setting dialog box will pop up. The parameters in this dialog box can be kept as default, click the OK button, and the publishing of PLC data in the MQTT server has been completed.

Example 5

As shown in Figure 3, the system provided by the embodiment of the present invention using Node-RED to convert PLC data into JSON format includes:

Platform operating environment building module 1, which is used to build the Node-RED platform operating environment for field device data collection and transmission, and run it;

Real-time data acquisition module 2, for utilizing OPC agreement to gather the real-time data of PLC sub-station;

The data conversion module 3 is used to convert and publish the data using OPC software;

Release data receiving module 4, for utilizing Node-RED platform to receive the release data of OPC software;

The format conversion module 5 is used to convert the received data into JSON format by using the Node-RED platform.

In the above-mentioned embodiments, the descriptions of each embodiment have their own emphases, and for parts that are not detailed or recorded in a certain embodiment, refer to the relevant descriptions of other embodiments.

The information interaction and execution process between the above-mentioned devices/units are based on the same idea as the method embodiment of the present invention, and its specific functions and technical effects can be found in the method embodiment section, and will not be repeated here.

Those skilled in the art can clearly understand that for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used for illustration. In practical applications, the above-mentioned functions can be assigned to different functional units, Completion of modules means that the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment may be integrated into one processing unit, or each unit may exist separately physically, or two or more units may be integrated into one unit, and the above-mentioned integrated units may adopt hardware It can also be implemented in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the protection scope of the present invention. For the specific working process of the units and modules in the above system, reference may be made to the corresponding process in the foregoing method embodiments.

2. Application examples:

Application example

The method for converting PLC data into JSON format by using Node-RED provided by the embodiment of the present invention can be applied to centralized monitoring equipment for data information in chemical and metallurgical industries. Real-time treatment and monitoring of wastewater and sewage.

An embodiment of the present invention provides a computer device, which includes: at least one processor, a memory, and a computer program stored in the memory and operable on the at least one processor, and the processor executes the The steps in any of the above method embodiments are implemented when the computer program is described.

An embodiment of the present invention also provides a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the steps in the foregoing method embodiments can be implemented.

The embodiment of the present invention also provides an information data processing terminal, the information data processing terminal is used to provide a user input interface to implement the steps in the above-mentioned method embodiments when the information data processing terminal is implemented on an electronic device, the information data Processing terminals are not limited to mobile phones, computers, and switches.

The embodiment of the present invention also provides a server, which is configured to provide a user input interface to implement the steps in the foregoing method embodiments when executed on an electronic device.

An embodiment of the present invention provides a computer program product. When the computer program product is run on an electronic device, the electronic device can realize the steps in the foregoing method embodiments when executed.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the procedures in the method of the above-mentioned embodiments in the present application can be completed by instructing related hardware through a computer program. The computer program can be stored in a computer-readable storage medium. The computer program When executed by a processor, the steps in the above-mentioned various method embodiments can be realized. Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device capable of carrying computer program codes to the photographing device/terminal device, recording medium, computer memory, read-only memory (Read-Only Memory, ROM), random access memory (Random AccessMemory, RAM), electrical carrier signals, telecommunication signals, and software distribution media. Such as U disk, mobile hard disk, magnetic disk or optical disk, etc.

In the above-mentioned embodiments, the descriptions of each embodiment have their own emphases, and for parts that are not detailed or recorded in a certain embodiment, refer to the relevant descriptions of other embodiments.

3. Evidence of the relevant effects of the embodiment:

A water plant in a city's economic and technological development zone is carrying out smart information construction, and its goal is to use the smart large-screen visualization technology to display the digital twin water plant online in real time. In the process of intelligent informatization construction, it is necessary to collect PLC real-time data of each section in the water plant. Due to the different PLC manufacturers on site, a common communication protocol is needed to collect real-time data from different PLC manufacturers. At this time, the OPC communication protocol is used. According to the method described in this article, after using the OPC communication protocol, the equipment usage and production data of all sections can be collected to the server of the smart water plant. Although the real-time data of the PLC has been collected, the smart large-screen visualization technology needs to display the data online in real time through the web page. The web browser cannot directly obtain the real-time data of the PLC from the OPC communication protocol. At this time, the Node-RED platform is needed. Convert the format of the PLC real-time data collected by the OPC communication protocol into a common data format that can be received by web browsers——JSON format. At this time, the equipment usage and production data of the PLC in each section of the water plant can be directly displayed online on the web browser. Figure 4 is an effect diagram of the real-time online display of production data of the smart water plant visualization technology implemented by this method.

The above is only a preferred specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field is within the technical scope disclosed in the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles shall fall within the protection scope of the present invention.

Claims (10)

1. A method utilizing Node-RED to realize PLC data conversion into JSON format, is characterized in that, being applied to information data processing terminal, the method may further comprise the steps: S1, build and run the Node-RED platform operating environment for field device data collection and transmission; S2, using the OPC protocol to collect real-time data of the PLC sub-station; S3, using OPC software to convert and publish the real-time data collected in step S2; S4, using the Node-RED platform to receive the release data of the OPC software; S5, use the Node-RED platform to convert the received published data into JSON format, and use the data debugging node that comes with the Node-RED platform to test the converted data. 2. the method utilizing Node-RED to realize PLC data conversion into JSON format according to claim 1, it is characterized in that, in step S1, field equipment comprises: one in PLC equipment, flowmeter, pressure gauge, temperature gauge one or more species. 3. utilize Node-RED according to claim 1 to realize the method that PLC data is converted into JSON format, it is characterized in that, in step S1, set up the Node-RED platform operating environment that is used for field equipment data collection and transmission, and The operation specifically includes the following steps: (1) Install the Node-RED platform operating environment: ①Search and download the Node.msi software installation package; ② Install the software on the Node.msi software installation package; ③ Open the command prompt of the Windows system with administrator privileges; ④Copy the code npm config set registry http://registry.npmmirror.com into the input box and run the code; ⑤ Copy the code npminstall-g--unsafe-perm node-red pm2 pm2-windows-startup pm2-windows-service into the input box and run the code; (2) Use the CMD command prompt to run the Node-RED platform; ① Open the command prompt of the Windows system; ②Copy the code C:\Users\Administrator\AppData\Roaming\npm\node-red.cmd into the input box and press Enter to run the code. 4. utilize Node-RED according to claim 1 to realize the method that PLC data is converted into JSON form, it is characterized in that, in step S2, utilize the real-time data of OPC agreement to gather PLC substation to comprise the following steps: Step 1, establish a data collection channel; Step 2, create new PLC data in the newly created data channel; Step 3, test the correctness of the data. 5. utilize Node-RED according to claim 1 to realize the method that PLC data is converted into JSON form, it is characterized in that, in step S3, utilize OPC software to convert data and publish and comprise the following steps: The OPC software converts the collected PLC data into an MQTT service through the IoT Gateway for external release. 6. a kind of realization claim 1-5 utilizes Node-RED to realize the method that PLC data is converted into JSON format and utilizes Node-RED to realize that PLC data is converted into JSON format system, it is characterized in that, described utilize Node -RED implements PLC data conversion into JSON format system includes: The language operating environment building module (1) is used to build the Node-RED platform operating environment for field device data collection and transmission, and run it; The real-time data acquisition module (2), is used for utilizing OPC agreement to gather the real-time data of PLC sub-station; Data transformation module (3), is used for utilizing OPC software to transform and release data; Release data receiving module (4), for utilizing Node-RED platform to receive the release data of OPC software; The format conversion module (5) is used to utilize the Node-RED platform to convert the received data into JSON format. 7. A program storage medium for receiving user input, characterized in that the stored computer program enables the electronic device to execute the method for converting PLC data into JSON format using Node-RED according to any one of claims 1-5. 8. A computer device, characterized in that the computer device comprises a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor performs claim 1 -A method for converting PLC data into JSON format using Node-RED as described in any item. 9. A computer-readable storage medium, storing a computer program, characterized in that, when the computer program is executed by a processor, the processor is made to perform any one of claims 1-5 using Node-RED to achieve The method of converting PLC data to JSON format. 10. A centralized monitoring device for data information in the chemical industry and metallurgical industry, characterized in that, the centralized monitoring device for data information in the chemical industry and metallurgical industry implements the use of Node-RED to realize PLC data conversion as described in any one of claims 1-5. method in JSON format.

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