Data transmission method and system based on PLC

Abstract

The invention is suitable for the technical field of data transmission, and particularly relates to a PLC-based data transmission method and system, and the method comprises the steps: constructing an event template with a threshold value or a logic expression as an element, configuring an event monitor, collecting the real-time data of a field device, reading effective fluctuations, filling the effective fluctuations into the event template, and completing the data transmission. Generating an event; the method comprises the following steps: creating a key value block consisting of a key domain and a value domain, migrating an event into the value domain, extracting an abstract, migrating the abstract into the key domain, creating processing flows corresponding to the key domain one by one, embedding an interrupt mechanism into the key value block, and delimiting a fluctuation range. According to the method, by determining the priority of the key value block, production resource distribution can be optimized, it is ensured that the production task can be processed in time, by generating the snapshot, task data can be prevented from being lost, the suspended task can be rapidly restarted, the response efficiency of a PLC is greatly improved, and continuous and stable operation of field equipment is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of data transmission, and in particular to a PLC-based data transmission method and system. Background Art

[0002] PLC, or programmable logic controller, is a device specifically used for industrial automation control. In the PLC production system, production data collected by sensors, actuators and other devices are processed through multiple protocols such as serial communication, Ethernet or field bus, thereby achieving real-time monitoring and adjustment of the industrial production process.

[0003] However, existing PLC data transmission is generally based on polling. PLC will check the status of each input / output production equipment in turn according to a fixed period and collect production data. However, this method has problems of data transmission delay and bandwidth waste, because even if there is no abnormality or change in the production equipment, PLC will still transmit data in each periodic polling. Therefore, "how to drive PLC to perform data transmission based on events" is the technical problem that the present invention needs to solve. Summary of the invention

[0004] The purpose of the present invention is to provide a data transmission method and system based on PLC to solve the problem of "how to trigger PLC to perform data transmission driven by events" mentioned in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: A data transmission method based on PLC, the method comprising: Construct an event template with thresholds or logical expressions as elements, configure an event listener, collect real-time data from field equipment, and read out effective fluctuations, fill the effective fluctuations into the event template, and generate an event; Creating a key-value block consisting of a key domain and a value domain, migrating the event to the value domain, extracting a summary, and migrating the summary to the key domain, creating a processing flow corresponding to the key domain, embedding an interrupt mechanism into the key-value block, defining a fluctuation range, determining whether the real-time data exceeds the fluctuation range, and if so, activating the interrupt mechanism, generating an interrupt signal, and transmitting the interrupt signal to the field device via a transmission link between the PLC and the field device; Query the pre-built comparison table to determine the priority of the key value block. When receiving the interrupt signal, judge the priority of the key value block and the ongoing task. If the priority of the key value block is higher, terminate the ongoing task, query the target process using the key field, and activate it. A snapshot of the real-time data is obtained, and the snapshot is divided into core data and auxiliary data, a buffer block is linked to the key value block, and the core data is synchronized to the buffer block.

[0006] Furthermore, the step of "configuring event listeners" includes: Integrating a multi-level processing mode in the event listener; Clustering the effective fluctuations into a plurality of categories, wherein the categories include at least slight fluctuations and major fluctuations, and configuring a corresponding relationship between a multi-level processing mode and each category; The processing mode corresponding to the slight fluctuation is: processing the event in the PLC; The processing mode corresponding to major fluctuations is: uploading the event to the preset terminal for processing.

[0007] Furthermore, the step of “migrating the event to the value domain” includes: embedding filtering rules into the value domain, filtering the events, deleting invalid parts of the events, retaining valid parts, and covering the value domain with the valid parts; The summaries of the effective parts are extracted, integrated to obtain a catalog set, and the processing flow is archived in the catalog set.

[0008] Furthermore, the method further comprises: Establish mapping between key value blocks, interrupt signals and events; The data interface of the key-value block is marked, a control command from a preset terminal is received via the data interface, and the control command is written into the key-value block after verification.

[0009] Further, the step of "activating the interrupt mechanism and generating an interrupt signal" includes: configuring a time window for the interrupt signal, and merging multiple interrupt signals within the same time window; Feedback data from field devices are collected via the transmission link, and the feedback data are added to the catalog set.

[0010] Furthermore, the method further comprises: If the priority of the ongoing task is higher than the priority of the key value block, create a task queue and load the target process into the task queue; When the task queue contains multiple target processes, the target processes are sorted in descending order of priority.

[0011] Furthermore, the step of “obtaining a snapshot of real-time data and dividing the snapshot into core data and auxiliary data” includes: Identifying the core data of the target process, comparing the difference between the core data of the target process and the core data of the snapshot, and sending the difference to the field device by using the transmission link; Auxiliary data of the target process is determined, and the field equipment is adjusted.

[0012] Furthermore, the system comprises: A generation module is used to construct an event template with thresholds or logical expressions as elements, configure an event listener, collect real-time data from field equipment, and read out effective fluctuations, fill the effective fluctuations into the event template, and generate an event; A transmission module is used to create a key-value block consisting of a key domain and a value domain, migrate the event to the value domain, extract a summary, and migrate the summary to the key domain, create a processing flow corresponding to the key domain, embed an interrupt mechanism into the key-value block, define a fluctuation range, determine whether the real-time data exceeds the fluctuation range, and if so, activate the interrupt mechanism, generate an interrupt signal, and transmit the interrupt signal to the field device via a transmission link between the PLC and the field device; An activation module is used to query a pre-built comparison table to determine the priority of the key-value block. When an interrupt signal is received, the priority of the key-value block and the ongoing task is determined. If the priority of the key-value block is higher, the ongoing task is terminated, the target process is queried using the key domain, and activated. The synchronization module is used to obtain a snapshot of the real-time data, divide the snapshot into core data and auxiliary data, link a buffer block to the key value block, and synchronize the core data to the buffer block.

[0013] Furthermore, the generation module includes: An integration unit, for integrating a multi-level processing mode in the event listener; The configuration unit is used to cluster the effective fluctuations into several categories, where the categories at least include: slight fluctuations and major fluctuations, and configure a corresponding relationship between a multi-level processing mode and each category.

[0014] Furthermore, the transmission module includes: A covering unit, used to embed filtering rules into the value domain, filter the events, delete invalid parts of the events, retain valid parts, and cover the value domain with the valid parts; An integration unit, used for extracting the summary of the effective part, integrating it to obtain a catalog set, and archiving the processing flow into the catalog set; A merging unit, configured to configure a time window for the interrupt signal and merge multiple interrupt signals within the same time window; The supplement unit is used to collect feedback data of the field device via the transmission link and supplement the feedback data into the directory set.

[0015] Compared with the prior art, the present invention has the following beneficial effects: By constructing event templates, events can be generated quickly, greatly improving the response speed of PLC, and enhancing event management and tracking capabilities. By reading effective fluctuations, the effectiveness of events can be greatly improved, saving data transmission and computing resources. By constructing key-value blocks, the flexibility of event access can be greatly enhanced, improving decision-making efficiency. By creating processing flows, events can be responded to in a timely manner to ensure the normal operation of field equipment, while reducing losses and harm caused by unexpected events. By determining the priority of key-value blocks, production resource allocation can be optimized to ensure that production tasks can be processed in a timely manner. By generating snapshots, task data loss can be avoided and suspended tasks can be quickly restarted, greatly enhancing the response efficiency of PLC and ensuring the continuous and stable operation of field equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A flowchart of a PLC-based data transmission method provided by an embodiment of the present invention; Figure 2 A first sub-flow chart of the PLC-based data transmission method provided by an embodiment of the present invention; Figure 3 A second sub-flow chart of the PLC-based data transmission method provided in an embodiment of the present invention; Figure 4 A third sub-flow chart of the PLC-based data transmission method provided in an embodiment of the present invention; Figure 5 A block diagram of a PLC-based data transmission system according to an embodiment of the present invention; Figure 6 A block diagram of a component generation module in a PLC-based data transmission system provided by an embodiment of the present invention; Figure 7 A block diagram of the composition of a transmission module in a PLC-based data transmission system provided in an embodiment of the present invention; Figure 8 A block diagram of the composition of a synchronization module in a PLC-based data transmission system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0018] In Example 1, Figure 1 The implementation process of the PLC-based data transmission method provided by an embodiment of the present invention is shown and described in detail below: S100: construct an event template with thresholds or logical expressions as elements, configure an event listener, collect real-time data from field equipment, and read out effective fluctuations, fill the effective fluctuations into the event template, and generate an event.

[0019] Construct an event template; for example, using a threshold or a logical expression as an element. The threshold can be that when a certain value of real-time data exceeds a predetermined range, an event is triggered. The logical expression is an expression composed of logical operators and logical variables. The logical expression can be that if the operating temperature of device A is greater than 50°C, device B is started for heat dissipation.

[0020] The event listener is mainly used to monitor the production status of field equipment in real time and determine whether the conditions (thresholds or logical variables) defined in the event template are met. If so, the valid fluctuations in the real-time data are read and filled into the event template to generate events. The real-time data includes the equipment parameters and production data of the field equipment. After determining the real-time data, the real-time data is preprocessed and the valid fluctuations are determined. The specific determination process is to record multiple fluctuations in the same time window as one valid fluctuation.

[0021] S200: Create a key-value block consisting of a key field and a value field, migrate the event to the value field, extract a summary, and migrate the summary to the key field, create a processing flow corresponding to the key field, wherein the processing flow is similar to an emergency response plan; embed an interrupt mechanism into the key-value block, define a fluctuation range, determine whether the real-time data exceeds the fluctuation range, and if so, activate the interrupt mechanism, generate an interrupt signal, and transmit the interrupt signal to the field device via the transmission link between the PLC and the field device.

[0022] Create a key-value block, where the key-value block is the basic data structure for storing events, which is divided into two parts: the key field and the value field, and there is a corresponding relationship between the two; transfer the event to the value field in the key-value block, and extract the summary of the event, where the summary extraction process is: first analyze the event and determine the type of event (production anomaly, equipment failure and quality fluctuation, etc.), then extract the key information in the event, the key information includes: event type, occurrence time, scope of impact, severity and response measures, etc., finally, synthesize the summary; transfer the summary to the key field, and configure a processing flow for each summary, where the processing flow is pre-determined by the production management personnel.

[0023] An interrupt mechanism is embedded in the key value block, wherein the interrupt mechanism is a specific method of performing hardware or software interruption on the field device; when the real-time data exceeds the fluctuation range, the interrupt mechanism is used to generate an interrupt signal, and the interrupt signal is sent to the field device, thereby controlling the field device to execute the specific method of the interrupt mechanism.

[0024] S300: Query the pre-built comparison table to determine the priority of the key-value block. When an interrupt signal is received, judge the priority of the key-value block and the ongoing task. If the priority of the key-value block is higher, terminate the ongoing task, use the key field to query the target process, and activate it.

[0025] According to the type of event or key information, the priority of the key value block is determined. If the priority of the key value block is higher than the priority of the ongoing task, the ongoing task is terminated, where the ongoing task refers to the task being run by the on-site equipment. After the ongoing task is terminated, the processing flow is queried through the key field in the key value block, the target flow is determined, and the on-site equipment is controlled to adjust the real-time data according to the target flow.

[0026] S400: Acquire a snapshot of the real-time data, divide the snapshot into core data and auxiliary data, link a buffer block to the key-value block, and synchronize the core data to the buffer block.

[0027] Get a snapshot of real-time data, where a snapshot refers to a static copy of real-time data at a specific moment, which represents the production status of the on-site equipment at this specific point in time. The snapshot is divided into core data and auxiliary data; the buffer block has the same storage structure as the key-value block. The buffer block is mainly used to store core data. The advantage of buffering core data is that it can quickly restart ongoing tasks.

[0028] In Example 2, Figure 2 The implementation process of the PLC-based data transmission method provided by an embodiment of the present invention is shown, and the steps of "configuring the event listener" are described in detail as follows: S101: Integrate a multi-level processing mode into the event listener.

[0029] S102: clustering the effective fluctuations into a plurality of categories, wherein the categories include at least slight fluctuations and major fluctuations, and configuring a corresponding relationship between a multi-level processing mode and each category; The processing mode corresponding to the slight fluctuation is: processing the event in the PLC; The processing mode corresponding to major fluctuations is: uploading the event to the preset terminal for processing.

[0030] The read valid fluctuations are divided into multiple categories; for example, the valid fluctuations are divided into slight fluctuations and major fluctuations. Slight fluctuations, that is, the fluctuation amplitude of real-time data is smaller; conversely, major fluctuations have a larger fluctuation amplitude; a corresponding processing mode is created for each category of valid fluctuations. For slight fluctuations, the events are processed directly in the PLC, and for major fluctuations, the events should be uploaded to the preset terminal for processing, where the preset terminal can be a cloud or other processing equipment.

[0031] In Example 3, Figure 3 The implementation process of the PLC-based data transmission method provided by an embodiment of the present invention is shown. The step of "migrating the event to the value domain" is described in detail as follows: S201: embedding filtering rules into the value domain, filtering the events, deleting invalid parts of the events, retaining valid parts, and covering the value domain with the valid parts.

[0032] Filtering rules are embedded in the value domain, wherein the filtering rules are based on predefined conditions to screen and filter out events that do not meet the conditions, where the conditions can be range, time or threshold; by filtering events, the accuracy of event processing can be improved; in this embodiment, events are mainly used to record fluctuations in field equipment; the part of the real-time data that is related to the fluctuation is determined as the valid part, and the part that is not related to the fluctuation is determined as the invalid part, the invalid part is deleted, and only the valid part is migrated to the value domain.

[0033] S202: extracting the summary of the effective part, integrating it to obtain a directory set, and archiving the processing flow into the directory set.

[0034] Extract the abstracts of the valid parts and integrate all the abstracts to generate a directory set. The integration process should include clustering and merging the abstracts separately. At the same time, according to the correspondence between the abstracts and the processing flow, the processing flow is also written to the specified location in the directory set.

[0035] In Example 4, different from Example 1, in this embodiment of the present invention, the method further includes: Establish mapping between key value blocks, interrupt signals and events; The data interface of the key-value block is marked, a control command from a preset terminal is received via the data interface, and the control command is written into the key-value block after verification.

[0036] By using mapping, a corresponding relationship between key-value blocks, interrupt signals and events is established. The advantage of this is that events can be quickly classified into key-value blocks, while greatly improving the efficiency of interrupt signal generation; a standardized data interface is set for the key-value block, which can be an API, communication protocol or other message transmission method; in addition to migrating events to the key-value block, control commands should also be written. After the key-value block receives the control command, the control command needs to be verified, where the control command comes from a preset terminal, which can be a production management personnel terminal, or a control instrument for on-site equipment, etc.

[0037] In Example 5, Figure 3 The implementation process of the PLC-based data transmission method provided by an embodiment of the present invention is shown. The step of "activating the interrupt mechanism and generating an interrupt signal" is described in detail as follows: S203: configuring a time window for the interrupt signal, and merging multiple interrupt signals in the same time window.

[0038] When interrupt signals are frequently triggered within the same time window, all interrupt signals generated within the corresponding time period are merged.

[0039] S204: Collect feedback data of the field equipment via the transmission link, and add the feedback data to the catalog set.

[0040] In addition to the directory and processing flow, the directory set should also include feedback data corresponding to each processing flow.

[0041] In Example 6, different from Example 1, in this embodiment of the present invention, the method further includes: If the priority of the ongoing task is higher than the priority of the key value block, create a task queue and load the target process into the task queue; When the task queue contains multiple target processes, the target processes are sorted in descending order of priority.

[0042] If the priority of the ongoing task is higher than the priority of the key value block, the target process corresponding to the key value block will be transferred to the task queue, and the target processes will be sorted in descending order of priority. When the ongoing task is completed, the target process ranked first in the task queue will be executed immediately.

[0043] In Example 7, Figure 4 The implementation process of the PLC-based data transmission method provided by an embodiment of the present invention is shown. The steps of "obtaining a snapshot of real-time data and dividing the snapshot into core data and auxiliary data" are described in detail as follows: S401: Identify the core data of the target process, compare the difference between the core data of the target process and the core data of the snapshot, and send the difference to the field device by using the transmission link.

[0044] Extract core data from the target process. Core data refers to key parameters or status indicators in the target process, usually including parameters such as operating speed, temperature and pressure. Compare these core data with the core data in the previously saved snapshot to determine the parts that need to be adjusted for the on-site equipment (i.e., the differences). Send the differences to the on-site equipment through the transmission link. After receiving the differences, the on-site equipment can adjust the production parameters accordingly.

[0045] S402: Determine auxiliary data of the target process and adjust the field equipment.

[0046] After the on-site equipment is adjusted, auxiliary data in the target process is extracted, where the auxiliary data may be production environment data or material supply data, etc. The on-site equipment is adjusted using the auxiliary data.

[0047] Figure 5 The structure block diagram of the PLC-based data transmission system provided by an embodiment of the present invention is shown. The PLC-based data transmission system 1 includes: The generating module 11 is used to construct an event template with a threshold value or a logical expression as an element, configure an event listener, collect real-time data of field equipment, and read out effective fluctuations, fill the effective fluctuations into the event template, and generate an event; The transmission module 12 is used to create a key-value block consisting of a key domain and a value domain, migrate the event to the value domain, extract a summary, and migrate the summary to the key domain, create a processing flow corresponding to the key domain, embed an interrupt mechanism into the key-value block, define a fluctuation range, determine whether the real-time data exceeds the fluctuation range, and if so, activate the interrupt mechanism, generate an interrupt signal, and transmit the interrupt signal to the field device via the transmission link between the PLC and the field device; The activation module 13 is used to query the pre-built comparison table to determine the priority of the key-value block. When receiving the interrupt signal, the priority of the key-value block and the ongoing task is determined. If the priority of the key-value block is higher, the ongoing task is terminated, the target process is queried using the key field, and activated. The synchronization module 14 is used to obtain a snapshot of the real-time data, divide the snapshot into core data and auxiliary data, link a buffer block to the key value block, and synchronize the core data to the buffer block.

[0048] Figure 6The structure block diagram of the PLC-based data transmission system provided by the embodiment of the present invention is shown, and the generating module 11 includes: An integration unit 111, used for integrating a multi-level processing mode in the event listener; The configuration unit 112 is used to cluster the effective fluctuations into several categories, where the categories at least include: slight fluctuations and major fluctuations, and configure a corresponding relationship between a multi-level processing mode and each category.

[0049] Figure 7 The structure block diagram of the PLC-based data transmission system provided by an embodiment of the present invention is shown, and the transmission module 12 includes: A covering unit 121, used to embed filtering rules into the value domain, filter the events, delete invalid parts of the events, retain valid parts, and cover the value domain with the valid parts; An integration unit 122, used to extract the summary of the effective part, integrate it to obtain a directory set, and archive the processing flow into the directory set; A merging unit 123, configured to configure a time window for the interrupt signal and merge multiple interrupt signals within the same time window; The supplement unit 124 is used to collect feedback data from the field device via the transmission link and supplement the feedback data into the directory set.

[0050] Figure 8 The structure block diagram of the PLC-based data transmission system provided by the embodiment of the present invention is shown, and the synchronization module 14 includes: The sending unit 141 is used to identify the core data of the target process, compare the difference between the core data of the target process and the core data of the snapshot, and send the difference to the field device by using the transmission link; The adjustment unit 142 is used to determine the auxiliary data of the target process and adjust the field device.

[0051] The generation module 11 is mainly used to complete step S100, the transmission module 12 is mainly used to complete step S200, the activation module 13 is mainly used to complete step S300, and the synchronization module 14 is mainly used to complete step S400; The integration unit 111 is mainly used to complete step S101, and the configuration unit 112 is mainly used to complete step S102; The covering unit 121 is mainly used to complete step S201, the integrating unit 122 is mainly used to complete step S202, the merging unit 123 is mainly used to complete step S203, and the supplementing unit 124 is mainly used to complete step S204; The sending unit 141 is mainly used to complete step S401, and the adjusting unit 142 is mainly used to complete step S402.

[0052] The functions that can be achieved by the PLC-based data transmission method are all completed by a computer device, which includes one or more processors and one or more memories, and at least one program code is stored in the one or more memories. The program code is loaded and executed by the one or more processors to achieve the functions of the PLC-based data transmission method.

[0053] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A data transmission method based on PLC, characterized in that: The method comprises: Construct an event template with thresholds or logical expressions as elements, configure an event listener, collect real-time data from field equipment, and read out effective fluctuations, fill the effective fluctuations into the event template, and generate an event; Creating a key-value block consisting of a key domain and a value domain, migrating the event to the value domain, extracting a summary, and migrating the summary to the key domain, creating a processing flow corresponding to the key domain, embedding an interrupt mechanism into the key-value block, defining a fluctuation range, determining whether the real-time data exceeds the fluctuation range, and if so, activating the interrupt mechanism, generating an interrupt signal, and transmitting the interrupt signal to the field device via a transmission link between the PLC and the field device; Query the pre-built comparison table to determine the priority of the key value block. When receiving the interrupt signal, judge the priority of the key value block and the ongoing task. If the priority of the key value block is higher, terminate the ongoing task, query the target process using the key field, and activate it. A snapshot of the real-time data is obtained, and the snapshot is divided into core data and auxiliary data, a buffer block is linked to the key-value block, and the core data is synchronized to the buffer block.

2. The PLC-based data transmission method according to claim 1, characterized in that: The steps of "configuring event listeners" include: Integrating a multi-level processing mode in the event listener; Clustering the effective fluctuations into several categories, the categories at least including: slight fluctuations and major fluctuations, and configuring a corresponding relationship between a multi-level processing mode and each category; The processing mode corresponding to the slight fluctuation is: processing the event in the PLC; The processing mode corresponding to major fluctuations is: uploading the event to the preset terminal for processing.

3. The PLC-based data transmission method according to claim 1, characterized in that: The step of "migrating the event to the value domain" includes: embedding filtering rules into the value domain, filtering the events, deleting invalid parts of the events, retaining valid parts, and covering the value domain with the valid parts; The summaries of the effective parts are extracted, integrated to obtain a catalog set, and the processing flow is archived in the catalog set.

4. The PLC-based data transmission method according to claim 1, characterized in that: The method further comprises: Establish mapping between key value blocks, interrupt signals and events; The data interface of the key-value block is marked, a control command from a preset terminal is received via the data interface, and the control command is written into the key-value block after verification.

5. The PLC-based data transmission method according to claim 3, characterized in that: The step of "activating the interrupt mechanism and generating an interrupt signal" includes: configuring a time window for the interrupt signal, and merging multiple interrupt signals within the same time window; Feedback data from field devices are collected via the transmission link, and the feedback data are added to the catalog set.

6. The PLC-based data transmission method according to claim 1, characterized in that: The method further comprises: If the priority of the ongoing task is higher than the priority of the key value block, create a task queue and load the target process into the task queue; When the task queue contains multiple target processes, the target processes are sorted in descending order of priority.

7. The PLC-based data transmission method according to claim 6, characterized in that: The step of "obtaining a snapshot of real-time data and dividing the snapshot into core data and auxiliary data" includes: Identifying the core data of the target process, comparing the difference between the core data of the target process and the core data of the snapshot, and sending the difference to the field device by using the transmission link; Auxiliary data of the target process is determined, and the field equipment is adjusted.

8. A data transmission system based on PLC, characterized in that: The system comprises: A generation module is used to construct an event template with thresholds or logical expressions as elements, configure an event listener, collect real-time data from field equipment, and read out effective fluctuations, fill the effective fluctuations into the event template, and generate an event; A transmission module is used to create a key-value block consisting of a key domain and a value domain, migrate the event to the value domain, extract a summary, and migrate the summary to the key domain, create a processing flow corresponding to the key domain, embed an interrupt mechanism into the key-value block, define a fluctuation range, determine whether the real-time data exceeds the fluctuation range, and if so, activate the interrupt mechanism, generate an interrupt signal, and transmit the interrupt signal to the field device via a transmission link between the PLC and the field device; An activation module is used to query a pre-built comparison table to determine the priority of the key-value block. When an interrupt signal is received, the priority of the key-value block and the ongoing task is determined. If the priority of the key-value block is higher, the ongoing task is terminated, the target process is queried using the key domain, and activated. The synchronization module is used to obtain a snapshot of the real-time data, divide the snapshot into core data and auxiliary data, link a buffer block to the key value block, and synchronize the core data to the buffer block.

9. The PLC-based data transmission system according to claim 8, characterized in that: The generation module comprises: An integration unit, for integrating a multi-level processing mode in the event listener; The configuration unit is used to cluster the effective fluctuations into several categories, where the categories at least include: slight fluctuations and major fluctuations, and configure a corresponding relationship between a multi-level processing mode and each category.

10. The PLC-based data transmission system according to claim 8, characterized in that: The transmission module comprises: A covering unit, used to embed filtering rules into the value domain, filter the events, delete invalid parts of the events, retain valid parts, and cover the value domain with the valid parts; An integration unit, used for extracting the summary of the effective part, integrating it to obtain a catalog set, and archiving the processing flow into the catalog set; A merging unit, configured to configure a time window for the interrupt signal and merge multiple interrupt signals within the same time window; The supplement unit is used to collect feedback data of the field device via the transmission link and supplement the feedback data into the directory set.

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