CN112751943A

CN112751943A - Data communication method, intermediate device and data communication system

Info

Publication number: CN112751943A
Application number: CN202110069160.1A
Authority: CN
Inventors: 梅沁; 缪大钧; 王译笙; 王挺; 曾鹏; 于海斌
Original assignee: Wuxi Power Supply Co of State Grid Jiangsu Electric Power Co Ltd
Current assignee: Wuxi Power Supply Co of State Grid Jiangsu Electric Power Co Ltd
Priority date: 2021-01-19
Filing date: 2021-01-19
Publication date: 2021-05-04

Abstract

The invention discloses a data communication method, intermediate equipment and a data communication system. The method comprises the following steps: acquiring data which is sent by a publishing terminal and based on a User Datagram Protocol (UDP); and if a subscription instruction of a subscription end is received, searching target data in the UDP-based data according to the subscription instruction, and pushing the target data to the subscription end. According to the technical scheme, the publishing and subscribing functions are realized through the intermediate device, unified and standardized communication is carried out on the network layer based on the UDP, a large amount of data between the publishing terminal and the subscribing terminal can be managed and maintained conveniently, and the communication efficiency is improved.

Description

Data communication method, intermediate device and data communication system

Technical Field

The embodiment of the invention relates to the technical field of Internet of things, in particular to a data communication method, intermediate equipment and a data communication system.

Background

The Internet of things (Internet of things) is an extension and expansion on the basis of the Internet, and a huge network is formed by combining various information sensing devices and the Internet, so that the interconnection and intercommunication of people, machines and objects at any time and any place is realized. An Object Linking and Embedding Unified Architecture (opua) for process control is a set of standardized framework integrating information model definition and service integration with communication standards. The opuua application can assume the roles of a publisher, which is the source of data, and a subscriber, which obtains and uses the data. The existing method usually adopts the mode of an OPCUA client side and a browser to carry out data communication, the communication time delay is long, and particularly under the condition that a one-to-many or many-to-many complex relationship exists between a publishing terminal and a subscribing terminal, a large amount of data is difficult to be uniformly and effectively managed and maintained.

Disclosure of Invention

The invention provides a data communication method, intermediate equipment and a data communication system, which are used for improving the communication efficiency and facilitating the management and maintenance of data.

In a first aspect, an embodiment of the present invention provides a data communication method, including:

acquiring data which is sent by a publishing terminal and based on a User Datagram Protocol (UDP);

and if a subscription instruction of a subscription end is received, searching target data in the UDP-based data according to the subscription instruction, and pushing the target data to the subscription end.

Optionally, the UDP-based data includes an OPCUA identifier, the issuer identifier, a topic name, and a topic value.

Optionally, the method further includes: storing the UDP-based data in a key-value structure to a data storage space.

Optionally, storing the UDP-based data in a key-value structure to a data storage space, including:

if the key which is the same as the theme name exists in the data storage space, updating the value corresponding to the key into the theme value; otherwise, a new key value is created in the data storage space according to the theme name and the theme value.

Optionally, the subscription instruction includes an OPCUA identifier, a subscriber identifier, and a target topic name.

Optionally, the method further includes: and updating a topic name list according to the subscription instruction, wherein the topic name list comprises the subscribed topic names.

Optionally, pushing the target data to the subscriber includes:

and if the target topic name is in the topic name list, pushing target data corresponding to the target topic name in the data storage space to the subscription end.

Optionally, the method further includes: recording the online states of the subscribing terminal and the publishing terminal

In a second aspect, an embodiment of the present invention provides an intermediate device, including:

one or more processors;

storage means for storing one or more programs;

when executed by the one or more processors, cause the one or more processors to implement the data communication method of the first aspect.

In a third aspect, an embodiment of the present invention provides a data communication system, including:

a publisher device, a subscriber device, and the intermediary device according to the second aspect;

the publishing terminal equipment is used for sending UDP-based data to the intermediate equipment;

and the subscriber end equipment is used for sending a subscription instruction to the intermediate equipment.

The embodiment of the invention provides a data communication method, intermediate equipment and a data communication system, wherein the method comprises the following steps: acquiring data which is sent by a publishing terminal and based on a User Datagram Protocol (UDP); and if a subscription instruction of a subscription end is received, searching target data in the UDP-based data according to the subscription instruction, and pushing the target data to the subscription end. According to the technical scheme, the publishing and subscribing functions are realized through the intermediate device, unified and standardized communication is carried out on the network layer based on the UDP, a large amount of data between the publishing terminal and the subscribing terminal can be managed and maintained conveniently, and the communication efficiency is improved.

Drawings

Fig. 1 is a flowchart of a data communication method according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a data communication method according to an embodiment of the present invention;

fig. 3 is a flowchart of a data communication method according to a second embodiment of the present invention;

fig. 4 is a schematic diagram of a hardware structure of an intermediate device according to a third embodiment of the present invention;

fig. 5 is a schematic structural diagram of a data communication system according to a fourth embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. In addition, the embodiments and features of the embodiments in the present invention may be combined with each other without conflict. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Before discussing exemplary embodiments in more detail, it should be noted that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although a flowchart may describe the steps as a sequential process, many of the steps can be performed in parallel, concurrently or simultaneously. In addition, the order of the steps may be rearranged. The process may be terminated when its operations are completed, but may have additional steps not included in the figure. The processes may correspond to methods, functions, procedures, subroutines, and the like.

Example one

Fig. 1 is a flowchart of a data communication method according to an embodiment of the present invention. The present embodiment is applicable to the case of performing data communication based on OPCUA. Specifically, the data communication method may be performed by an intermediate device. Further, the intermediate device includes, but is not limited to: desktop computers, notebook computers, servers, and the like.

As shown in fig. 1, the method specifically includes the following steps:

s110, data based on a User Datagram Protocol (UDP) sent by a publishing terminal is obtained.

Specifically, the publishing end (i.e., the PUB end) refers to an end that publishes data, and after the publishing end establishes network connection with the intermediate device (i.e., the Broker end), the publishing end can send its own data to the Broker end in a UDP message form based on the opuua.

S120, if a subscription instruction of a subscriber terminal is received, searching target data in the UDP-based data according to the subscription instruction, and pushing the target data to the subscriber terminal.

Specifically, the Broker terminal is a data caching and forwarding terminal, and can receive and store data from a publishing terminal, and push the stored data to a SUB terminal under the condition that a subscribing terminal (i.e., SUB terminal) subscribes; the SUB end is a data receiving end and can inform the Broker end of which data the Broker end subscribes to, and then receives the data pushed by the Broker end.

In the embodiment, a transmission mechanism of data among the PUB end, the Broker end and the SUB end is a publish/subscribe (PUB/SUB) mode, an application layer adopts an OPCUA protocol, and a network layer performs unified and standardized data communication based on UDP, so that timeliness of communication among devices is effectively improved; and the data is stored and forwarded by the Broker end and is interacted with the PUB end and the SUB section respectively, so that the maintenance cost of the equipment is reduced.

Fig. 2 is a schematic diagram of a data communication method according to an embodiment of the present invention. As shown in fig. 2, there may be one or more publishers and one or more subscribers, and the publishers send messages to the Broker, which is essentially a messaging middleware that is a software or hardware infrastructure that supports the transfer of data between distributed systems. The publisher and the subscriber only need to interact with the Broker terminal, and the Broker terminal provides support for forwarding data to one or more subscribers.

According to the data communication method provided by the embodiment of the invention, the publishing and subscribing functions are realized through the intermediate device, and unified and standardized communication is carried out on the network layer based on the UDP, so that a large amount of data between the publishing terminal and the subscribing terminal can be managed and maintained conveniently, and the communication efficiency is improved.

Example two

Fig. 3 is a flowchart of a data communication method according to a second embodiment of the present invention, where this embodiment is optimized based on the foregoing embodiment, and specifically describes a process of storing and forwarding data by an intermediate device. It should be noted that technical details that are not described in detail in the present embodiment may be referred to any of the above embodiments.

In this embodiment, the interaction between the PUB terminal, the Broker terminal and the SUB terminal mainly involves the following six stages:

1) the PUB terminal sends data based on UDP to the Broker terminal;

2) the Broker end receives data based on UDP and updates the data storage space;

3) the SUB terminal sends a subscription instruction to the Broker terminal;

4) the Broker end receives the order of reading and updates the subject name list;

5) the Broker end searches target data and sends the target data to the SUB end;

6) and the Broker end maintains the running states of the PUB end and the SUB end.

In this embodiment, the programming language adopts Java, the development environment adopts a Java language-related development integration environment IDEA15, the bottom layer communication adopts UDP, and the application layer content adopts the opua international standard. The publishing terminal equipment and the subscribing terminal equipment are collectively called as Internet of things equipment, and need to support JDK1.8 and above operating environment and Transmission Control Protocol/Internet Protocol (TCP/IP) Protocol stacks, which respectively support installation and operation of PUB terminal and SUB terminal programs; the Broker end operating environment is that on the basis of JDK1.8 and above and TCP/IP protocol stack, Redis3.2 and above versions are also installed.

Specifically, as shown in fig. 3, the method specifically includes the following steps:

s210, data based on UDP sent by a publishing terminal is obtained.

Optionally, the UDP-based data includes an OPCUA identifier, a publisher identifier, a topic name, and a topic value.

In this embodiment, the PUB sends data to the Broker fixed network port in the form of a UDP packet, where the content of the UDP packet includes: OPCUA identification, 4 byte integer, proving that the message is based on OPCUA; the PUB end ID is a 4-byte integer and is used for identifying the PUB from which the data comes; topic name, 32 byte string; subject value, 16 byte string.

S220, storing the UDP-based data to a data storage space in a key-value structure.

Specifically, the Broker end receives data based on UDP issued by the PUB end and updates a data storage space, and establishes a key-value structure in the cache, where a subject name of the data based on UDP is used as a key, and a corresponding PUB end ID and a subject value are used as values.

Further, S220 specifically includes: if the key with the same name as the theme name exists in the data storage space, updating the value corresponding to the key into the theme value; otherwise, a new key value is created in the data storage space according to the subject name and the subject value.

In this embodiment, in the process of updating the data storage space, if the topic name of the received UDP-based data is an existing topic name in the data storage space, the topic value corresponding to the topic name in the data storage space is updated by using the topic value of the received data; if the theme name does not exist in the data storage space, establishing a new theme name according to the received data and storing a corresponding theme value.

S230, receiving a subscription instruction from the subscriber? If yes, go to S240; otherwise, returning to the subscription instruction of the waiting subscription end.

In this embodiment, after each SUB terminal is online, a subscription instruction is sent to the Broker terminal to notify the Broker terminal that the SUB terminal is online and inform the SUB terminal of which topic names the SUB terminal subscribes.

Optionally, the subscription instruction includes an OPCUA identifier, a subscriber identifier, and a target topic name. The SUB terminal sends a subscription instruction to a Broker fixed network port in a UDP message form, wherein the UDP message content comprises: OPCUA identification, 4-byte integer, is proved to be an OPCUA message; the ID of the SUB end, a 4-byte integer, identifies which PUB end subscribes data; topic name, 32 byte string.

And S240, updating the topic name list according to the subscription instruction.

Specifically, the topic name list includes the subscribed topic names. In this embodiment, the Broker maintains a SUBlist of all subscribed topic names in the memory, and updates SUBlist once receiving the subscription instruction from the SUB terminal and determining the topic name subscribed by the SUB terminal.

S250, is the target topic name in the subscription instruction in the topic name list? If yes, go to S260; otherwise, return to S240.

S260, searching target data corresponding to the subject name in the data storage space.

Specifically, if the topic name subscribed by the SUB terminal is already recorded in SUBlist, the Broker terminal searches for the latest topic value corresponding to the topic name in the data storage space, and pushes the latest topic value as target data to the corresponding SUB terminal in the form of UDP message. The UDP message content includes: OPCUA identification, 4-byte integer, is proved to be the message of OPCUA; the PUB end ID is a 4-byte integer and identifies the source PUB of the data; topic name, 32 byte string; subject value, 16 byte string.

And S270, pushing the target data corresponding to the target topic name to the subscription terminal.

And S280, recording the online states of the subscribing terminal and the publishing terminal.

Specifically, the Broker end maintains the online status of the PUB end and the SUB end in the operation process, for example, while receiving or pushing data, the Broker end records whether the SUB end and the PUB end are online, and if not, cancels the relevant receiving or pushing operation.

In this embodiment, some attributes and corresponding functions are defined for the PUB end, the Broker end, and the SUB end, respectively, for implementing the data communication process. Table 1 is an attribute and function relationship table of the distribution end. The function of the distribution end is managed and realized according to the attributes shown in table 1.

TABLE 1 Attribute and functional relationship Table for distribution Ends

Table 2 is a table of attribute and function relationship of the Broker terminal. The Broker terminal is managed and functions according to the attributes shown in table 2.

TABLE 2 Broker end Attribute and function relationship Table

Table 3 is a table of attributes and functional relationships of the SUB terminal. The SUB terminal is managed and functions thereof are implemented according to the attributes shown in table 3.

Table 3 attribute and function relation table of SUB terminal

In the data communication method provided by the second embodiment of the invention, effective publishing and subscribing of data are realized by updating the data storage space and maintaining the topic name list; unified standardized communication is carried out on the network layer based on UDP, and the real-time running states of all devices in the network are uniformly maintained by the Broker end, so that the publishing end and the subscribing end are decoupled, the maintenance and management are facilitated, and the communication timeliness of the devices in the Internet of things is improved.

EXAMPLE III

Fig. 4 is a schematic diagram of a hardware structure of an intermediate device according to a third embodiment of the present invention. Intermediate devices include, but are not limited to: desktop computers, notebook computers, servers, and the like. As shown in fig. 4, the intermediate device provided in the present application includes a memory 32, a processor 31, and a computer program stored in the memory and executable on the processor, and when the processor 31 executes the computer program, the data communication method described above is implemented.

The intermediate device may also include a memory 32; the number of the processors 31 in the intermediate device may be one or more, and one processor 31 is taken as an example in fig. 4; memory 32 is used to store one or more programs; the one or more programs are executed by the one or more processors 31, so that the one or more processors 31 implement the data communication method as described in the embodiment of the present application.

The intermediate device further comprises: a communication device 33, an input device 34 and an output device 35.

The processor 31, the memory 32, the communication means 33, the input means 34 and the output means 35 in the intermediate device may be connected by a bus or other means, which is exemplified in fig. 4.

The input device 34 may be used to receive entered numeric or character information and to generate key signal inputs relating to user settings and function controls of the intermediate device. The output device 35 may include a display device such as a display screen.

The communication means 33 may comprise a receiver and a transmitter. The communication device 33 is configured to perform information transceiving communication according to the control of the processor 31.

The memory 32, which is a computer-readable storage medium, may be configured to store software programs, computer-executable programs, and modules, such as program instructions/modules corresponding to the data communication methods described in the embodiments of the present application. The memory 32 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created according to the use of the intermediate device, and the like. Further, the memory 32 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some examples, memory 32 may further include memory located remotely from processor 31, which may be connected to an intermediary device via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

On the basis of the above-described embodiments, the present embodiment also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a data communication apparatus, implements a data communication method in any of the above-described embodiments of the present invention, the method including: acquiring data which is sent by a publishing terminal and based on a User Datagram Protocol (UDP); and if a subscription instruction of a subscription end is received, searching target data in the UDP-based data according to the subscription instruction, and pushing the target data to the subscription end.

Embodiments of the present invention provide a data communications system including computer-executable instructions, which may be embodied in any combination of one or more computer-readable media. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer-readable storage medium may be, for example, but is not limited to: an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a Read Only Memory (ROM), an Erasable Programmable Read Only Memory (EPROM), a flash Memory, an optical fiber, a portable CD-ROM, an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. A computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated data signal may take a variety of forms, including, but not limited to: an electromagnetic signal, an optical signal, or any suitable combination of the foregoing. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, fiber optic cable, Radio Frequency (RF), etc., or any suitable combination of the foregoing.

Computer program code for carrying out operations for aspects of the present application may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C + +, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet service provider).

Example four

Fig. 5 is a schematic structural diagram of a data communication system according to a fourth embodiment of the present invention. As shown in fig. 5, the system includes a publisher device 410, a subscriber device 420, and an intermediary device 430; the publishing terminal 410 is configured to send UDP-based data to the middleware 430; the subscriber device 420 is configured to send a subscription instruction to the middleware 430.

Optionally, the middleware 430 is further configured to store the UDP-based data in a key-value structure to a data storage space.

Optionally, the intermediate device 430 is specifically configured to: if the key which is the same as the theme name exists in the data storage space, updating the value corresponding to the key into the theme value; otherwise, a new key value is created in the data storage space according to the theme name and the theme value.

Optionally, the intermediate device 430 is further configured to: and updating a topic name list according to the subscription instruction, wherein the topic name list comprises the subscribed topic names.

Optionally, the intermediate device 430 is specifically configured to: and if the target topic name is in the topic name list, pushing target data corresponding to the target topic name in the data storage space to the subscription end.

Optionally, the intermediate device 430 is further configured to: and recording the online states of the subscribing terminal and the publishing terminal.

From the above description of the embodiments, it is obvious for those skilled in the art that the present invention can be implemented by software and necessary general hardware, and certainly, can also be implemented by hardware, but the former is a better embodiment in many cases. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which may be stored in a computer-readable storage medium, such as a floppy disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a FLASH Memory (FLASH), a hard disk or an optical disk of a computer, and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device) to execute the data communication method according to the embodiments of the present invention.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method of data communication, comprising:

2. The method of claim 1, wherein the UDP-based data includes an OPCUA identification, the publisher identification, a topic name, and a topic value.

3. The method of claim 2, further comprising:

storing the UDP-based data in a key-value structure to a data storage space.

4. The method of claim 3, wherein storing the UDP based data in a key-value structure to a data storage space comprises:

if the key which is the same as the theme name exists in the data storage space, updating the value corresponding to the key into the theme value;

otherwise, a new key value is created in the data storage space according to the theme name and the theme value.

5. The method of claim 1, wherein the subscription instructions comprise an OPCUA identification, a subscriber identification, and a target topic name.

6. The method of claim 5, further comprising:

and updating a topic name list according to the subscription instruction, wherein the topic name list comprises the subscribed topic names.

7. The method of claim 6, wherein pushing the target data to the subscriber comprises:

8. The method of claim 1, further comprising:

and recording the online states of the subscribing terminal and the publishing terminal.

9. An intermediary device, comprising:

one or more processors;

storage means for storing one or more programs;

when executed by the one or more processors, cause the one or more processors to implement a data communication method as claimed in any one of claims 1-8.

10. A data communication system, comprising: a publisher device, a subscriber device, and the intermediary device of claim 9;