Information organization acquisition method and system for real data in PLC (Programmable Logic Controller)

Abstract

The invention provides an information organization obtaining method and system for real data in a PLC, and the method comprises the steps: 1, carrying out the serialization of a software object of a to-be-downloaded control application program to generate an information summary table when an upper computer carries out the downloading operation, and jointly downloading the information summary table and the to-be-downloaded control application program to a lower computer PLC for storage; 2, when the upper computer performs online monitoring, the information summarization table is obtained from the lower computer and a symbol table is constructed in a serialized mode; 3, the upper computer obtains the real program data of the lower computer by inquiring the symbol table. According to the method, the performance of the upper computer for acquiring the program data of the lower computer during program monitoring can be remarkably improved, the lower computer only needs to store the information summarizing table without calculating real data information, the computing power burden of the lower computer is greatly reduced, only when the control application program of the lower computer is updated, the upper computer acquires the information summarizing table from the lower computer again, and the computing power burden of the lower computer is greatly reduced. And the communication overhead of upper and lower computers is also reduced.

Description

Technical Field

[0001] This invention relates to the field of industrial automation technology, and more specifically, to a method and system for organizing and acquiring real data in a PLC. Background Technology

[0002] A Programmable Logic Controller (PLC) is a digital computer specifically designed for use in industrial control systems, used for control and monitoring in automated production processes. It employs a programmable memory that stores instructions for performing logical operations, sequential control, timing, counting, and arithmetic operations. Through digital and analog inputs and outputs, the PLC can control various types of mechanical equipment or production processes, achieving automated control. During PLC operation, a host computer can monitor the program running on the slave computer, thereby obtaining the real-time values ​​of variables in the PLC's control application and thus the actual control status of the actuators controlled by the PLC.

[0003] In industrial applications, real-time acquisition of actual operating data from the lower-level machine (PLC) is crucial. Before numerical monitoring of the program, data from the lower-level program needs to be acquired for verification. Therefore, it is necessary to organize and acquire the actual data from the lower-level machine and provide it to the upper-level machine for monitoring. Currently, during the data monitoring cycle, the computing power of the lower-level machine is often used to organize and acquire data from the actual control application. This existing method increases the performance load of the lower-level machine and adds unnecessary computational burden to the PLC. Furthermore, the continuous calculation of actual program data by the lower-level machine and its return to the upper-level machine also creates additional communication overhead between the two systems.

[0004] Patent document US10877455B2 discloses a method and apparatus for monitoring and reconfiguring a software-defined PLC. The method includes: when monitoring a PLC fails, a soft daemon process acquires the operating status of each physical core on each server in a server cluster, and the operating status of each microkernel on each physical core; based on the operating status of each physical core on each server and the operating status of each microkernel on each physical core, a target microkernel is determined; and a reconfiguration instruction is sent to the target microkernel to instruct the virtual PLC to reconfigure on the target microkernel. This patent does not address the area of ​​acquiring actual control application data in the PLC, but rather focuses on solving the reconfiguration problem when a PLC fails. It cannot completely solve the existing technical problems and does not meet the needs of this invention. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for organizing and acquiring real data in a PLC.

[0006] The method for organizing and acquiring real data in a PLC according to the present invention includes:

[0007] Step 1: When the host computer performs the download operation, the software object of the control application to be downloaded is serialized to generate an information summary table. The information summary table includes the software object name, dependency relationship, fingerprint identifier, monitoring information and basic data. The information summary table and the control application to be downloaded are downloaded together to the lower computer PLC for storage.

[0008] Step 2: When the host computer is monitoring online, it obtains the information summary table from the slave computer and serializes it to construct a symbol table;

[0009] Step 3: The host computer obtains the actual program data of the lower computer by querying the symbol table. When the requested variable name is not the fully qualified name, recursive matching is performed according to the namespace hierarchy: first, the variables inside the current program unit are matched, then the variables in the same namespace are matched, and finally the global variables are matched.

[0010] Preferably, the serialization-generated information summary table includes:

[0011] For software objects containing variable members, the variable object resolver and the software object type resolver are invoked in parallel.

[0012] For software objects without variable members, only the software object resolver of its own type is invoked;

[0013] The special attributes of software objects are stored separately in the basic data. These special attributes are type-exclusive attributes, including the network interface attributes of network global variables.

[0014] Preferably, the symbol table construction process includes:

[0015] Analyze the dependencies and subordination relationships of each software object in the summary information table;

[0016] Generate a unique symbol for each software object, which contains both standard information fields and personalized information fields;

[0017] The personalized information fields are parsed based on the software object type. The standard information fields include data type and initial value, while the personalized information fields include variable storage area and constant identifier.

[0018] Preferably, the namespace hierarchy rule for recursive matching is:

[0019] When a match fails, the process proceeds to the parent namespace, up to the root namespace.

[0020] When a match is successful, the variable's data type, initial value, constant identifier, and region information are returned.

[0021] Preferably, the information summary table is transmitted in the form of a download target object, which is generated by data encapsulation of the control application to be downloaded and the information summary table.

[0022] The information organization and acquisition system for real data in a PLC provided by the present invention includes:

[0023] Module M1: When the host computer performs the download operation, it serializes the software object of the control application to be downloaded to generate an information summary table. The information summary table includes the software object name, dependency relationship, fingerprint identifier, monitoring information and basic data. The information summary table and the control application to be downloaded are downloaded together to the lower computer PLC for storage.

[0024] Module M2: When the host computer is monitoring online, it obtains the information summary table from the slave computer and serializes it to construct a symbol table;

[0025] Module M3: The host computer obtains the actual program data of the lower computer by querying the symbol table. When the requested variable name is not the fully qualified name, recursive matching is performed according to the namespace hierarchy: first, variables within the current program unit are matched, then variables in the same namespace are matched, and finally global variables are matched.

[0026] Preferably, the serialization-generated information summary table includes:

[0027] For software objects containing variable members, the variable object resolver and the software object type resolver are invoked in parallel.

[0028] For software objects without variable members, only the software object resolver of its own type is invoked;

[0029] The special attributes of software objects are stored separately in the basic data. These special attributes are type-exclusive attributes, including the network interface attributes of network global variables.

[0030] Preferably, the symbol table construction process includes:

[0031] Analyze the dependencies and subordination relationships of each software object in the summary information table;

[0032] Generate a unique symbol for each software object, which contains both standard information fields and personalized information fields;

[0033] The personalized information fields are parsed based on the software object type. The standard information fields include data type and initial value, while the personalized information fields include variable storage area and constant identifier.

[0034] Preferably, the namespace hierarchy rule for recursive matching is:

[0035] When a match fails, the process proceeds to the parent namespace, up to the root namespace.

[0036] When a match is successful, the variable's data type, initial value, constant identifier, and region information are returned.

[0037] Preferably, the information summary table is transmitted in the form of a download target object, which is generated by data encapsulation of the control application to be downloaded and the information summary table.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] This invention proposes a method for organizing and acquiring real data in a PLC. The method uses an information summary table and its constructed symbol table in the host computer to provide real data information in the PLC, which can significantly improve the performance of the host computer in acquiring real data during program monitoring. The information summary table is downloaded and loaded during download and after going online, respectively. The slave computer only needs to process the information summary table and does not need to perform data calculations, which can greatly reduce the computing power burden of the slave computer and the communication overhead between the host and slave computers. Attached Figure Description

[0040] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0041] Figure 1 Flowchart of the method for organizing and acquiring real data in a PLC;

[0042] Figure 2 A system architecture diagram obtained for organizing real data in a PLC. Detailed Implementation

[0043] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0044] Example 1

[0045] like Figure 1 As shown, this invention provides a method for organizing and acquiring real data in a PLC.

[0046] A first aspect of this invention provides a method for organizing and acquiring real data in a PLC, comprising:

[0047] Step S1: When the host computer performs the download operation, the download object is serialized into an information summary table according to the content required by the host computer.

[0048] The process of reserializing the downloaded object into an efficient information table based on the content required by the host computer includes the following three steps:

[0049] Load data from the program to be downloaded;

[0050] Based on this data, generate downloadable objects and their corresponding software object summary information, including:

[0051] Different serialization methods are used for different software object types to perform personalized parsing: different types of software objects use different serialization parsers corresponding to their types; software objects containing variable members use both variable object parsers and software object parsers; software objects without variable members only use the software object parser of their own type.

[0052] For software objects without special attributes: store the summary information of the software object according to the serialization standard;

[0053] Handling software objects with special attributes: Store the special attributes in the software object summary information.

[0054] Organize the summary information of the software objects corresponding to each downloaded object into an information summary table.

[0055] Among them, special attributes of software objects refer to attributes that only this type of software object possesses and that other types of software objects do not possess, such as the network port attribute of a global network variable.

[0056] Step S2: During the download operation, the information summary table and the program to be downloaded are downloaded together to the programmable logic controller, including:

[0057] The information summary table (summaryDataMap) is organized into a downloadable section, i.e., summary data. For details on the specific method, please refer to the second aspect of the present invention.

[0058] The program to be downloaded generated by the organization and the summary data generated in step 1 constitute a single target object to be downloaded.

[0059] Download the target object generated in step 2 to the lower-level machine, so that the information summary table (summaryDataMap) exists in the lower-level machine and corresponds one-to-one with the controlled application;

[0060] Step S3: After online operation on the host computer, the information summary table is obtained and serialized again to form a symbol table, including:

[0061] The host computer performs online operations and obtains the information summary table (summaryDataMap) corresponding to the current control application program from the slave computer.

[0062] The information summary table is serialized according to a specified method, the serialization method of which is detailed in the third aspect of the present invention, to construct a data information symbol table (symbolMap) for the lower-level machine real control application.

[0063] Step S4: During monitoring, the host computer retrieves the actual program information of the slave computer from the symbol table, including:

[0064] The host computer searches for variables by name in the stored symbol map, but it is uncertain whether the variable name is the full name.

[0065] When the host computer requests the full name of a variable, it retrieves and returns detailed information about the variable from the symbol table, such as the variable's data type, initial value, whether it is a constant, and its region.

[0066] When it is unknown whether the host computer requests a fully qualified variable name, according to the fully qualified name unknown matching rule defined by this invention, obtaining the detailed information of the variable includes the following four steps:

[0067] Step 1: First, match the internal variables of the program unit to which the request information belongs. If a match is found, obtain its detailed information. If no match is found, proceed to Step 2.

[0068] Step 2: Match variables within the same namespace. If a match is found, retrieve its detailed information. If no match is found, proceed to Step 3.

[0069] Step 3: Match global variables. If a match is found, retrieve its detailed information; otherwise, the match fails.

[0070] Step 4: Search the symbol table for the matched variable and return the detailed information of the variable.

[0071] Step S5: When the program in the lower-level machine is modified, the upper-level machine re-obtains the information summary table corresponding to the new control application in the lower-level machine, re-serializes it to form a new symbol table, and requests data from the new symbol table and updates the monitored object information, including:

[0072] The lower-level machine notifies the upper-level machine that the control application (program) in the lower-level machine has been changed to a new program;

[0073] When the host computer receives a program change event from the slave computer, the host computer obtains the information summary table corresponding to the new program from the slave computer, hereinafter referred to as (newSummaryDataMap);

[0074] Reconstruct and update the symbol table of the real control application based on the information summary data map (newSummaryDataMap);

[0075] The host computer retrieves the control application information from (symbolMap). Since (symbolMap) is updated according to (newSummaryDataMap), the data information provided by (symbolMap) at this time is the actual data information in the current control application (newProgram).

[0076] After obtaining the target information, the host computer performs subsequent data processing.

[0077] A second aspect of this invention is to provide a summary data map for a control application program in a PLC and a method for serializing the summary data map thereon, for serializing the downloaded program into an efficient summary data map, including:

[0078] For the software program to be downloaded, for each program unit and software object, software information is obtained from the host computer and serialized to generate a summary information of the software object, including:

[0079] Software object name (Name): The name identifier of this software object;

[0080] Dependency: Information about how this software object depends on other software objects;

[0081] Fingerprint: Unique identification information for each part of the object in this software;

[0082] Monitor: The necessary information and data required by this software object when performing monitoring;

[0083] BasicData: Stores personalized information for various types of software objects.

[0084] The software object summary information for each software object is organized into an information summary table, using the software object name as an identifier and recording the software object type and software object summary information.

[0085] A third aspect of this invention provides a symbol map derived from an information summary data map and its serialization method, used to parse the information summary data map and provide query results, including:

[0086] Parse the software object summary information for each software object from the summaryDataMap;

[0087] The software object summary information is re-serialized to obtain a unique symbol for each software object in the running software program. Standard information (i.e., information that all software objects must have) and personalized information (i.e., information unique to some specific types of software objects) are parsed according to the software object type.

[0088] Update each symbol based on the software object dependencies and dependencies contained in the information summary table;

[0089] Construct a symbol table (symbolMap) to store the actual control application information of the lower-level machine and store it in the upper-level machine.

[0090] The fourth aspect of this invention is to provide a system for organizing and acquiring real data in a PLC, such as... Figure 2 As shown, it includes:

[0091] Instruction sending module: Used to send instructions to the target programmable logic controller to obtain information summary table information;

[0092] Core relay module: Used to establish connections at the front end, connect to the programmable logic controller (PLC), and monitor for changes in the lower-level machine program. It includes the following functions:

[0093] The user front-end, i.e., the host computer, requests to query the actual data in the slave computer;

[0094] Used to establish a connection between the server and the programmable logic controller to ensure normal communication;

[0095] The server monitors data through a specific channel to obtain real-time information on whether the program in the lower-level machine has been modified.

[0096] Data processing module: This module serializes the downloaded software object to generate an information summary table, serializes the information summary table to generate a lower-level machine's actual data symbol table, and performs data queries. Its functions include:

[0097] Used to serialize and generate an information summary table based on the downloaded software object, and to serialize and generate a lower-level machine real data symbol table based on the information summary table;

[0098] Used to store information summary tables and lower-level machine actual data symbol tables;

[0099] It is used to receive query requests from the host computer and return the actual control application data information in the lower-level machine through full name matching and symbol retrieval.

[0100] Definition of noun:

[0101] Software object summary information: The software object to be downloaded is serialized to form a summary of information about the software object;

[0102] Information Summary Table: Organizes and updates the summary information of the software objects corresponding to all objects to be downloaded, including all the actual program data information of the lower-level machines required by the host computer for monitoring and other operations.

[0103] Real data symbol table: Stored in the host computer, it is generated from the serialization information summary table. When the host computer needs to obtain the real program data of the slave computer, it directly queries this table.

[0104] Software object: refers to the part of the program that needs to be downloaded and executed in the control application. All software objects together make up the control application.

[0105] Serialization: Organizes all objects to be downloaded in the control application into a specific format according to certain rules and business needs. In the example of this invention, the specific format is an information summary table and a symbol table, and can be restored to the original object when needed.

[0106] Unknown Fully Name Matching Rule: When matching an unknown fully named object used in a program segment, the system first checks if it matches the same variable as another variable in the current namespace. If the variable does not exist in the current namespace, the search continues in the parent namespaces until a match is found. If no match is found even after reaching the root namespace, the match fails.

[0107] This invention proposes a method for organizing and acquiring real data in a PLC. Before each download, the host computer constructs an information summary table and downloads it along with the downloaded content. In subsequent operations, such as during monitoring, when real data information from the slave device is needed, the host computer retrieves the information summary table of the real control application from the slave device, parses it, and constructs a symbol table to obtain the real data information from the PLC. This avoids repeatedly retrieving static information such as data types from the slave device, significantly reducing the communication overhead of the host computer in scenarios requiring real data acquisition, such as monitoring. During this process, the slave device only needs to store the information summary table and does not need to perform data calculations, thus greatly reducing the computational burden on the slave device.

[0108] Example 2

[0109] The present invention also provides an information organization and acquisition system for real data in a PLC. The information organization and acquisition system for real data in a PLC can be implemented by executing the process steps of the information organization and acquisition method for real data in a PLC. That is, those skilled in the art can understand the information organization and acquisition method for real data in a PLC as a preferred embodiment of the information organization and acquisition system for real data in a PLC.

[0110] This invention provides an information organization and acquisition system for real data in a PLC, comprising: Module M1: When the host computer performs a download operation, it serializes the software objects of the control application to be downloaded to generate an information summary table. The information summary table includes software object names, dependencies, fingerprint identifiers, monitoring information, and basic data. The information summary table and the control application to be downloaded are downloaded together to the lower-level PLC for storage; Module M2: When the host computer is monitoring online, it obtains the information summary table from the lower-level PLC and serializes it to construct a symbol table; Module M3: The host computer obtains the real program data of the lower-level PLC by querying the symbol table. When the requested variable name is not a fully qualified name, recursive matching is performed according to the namespace hierarchy: first, variables within the current program unit are matched; then, variables in the same-level namespace are matched; and finally, global variables are matched.

[0111] The serialization-generated information summary table includes: for software objects containing variable members, invoking the variable object resolver and the software object type resolver in parallel; for software objects without variable members, only invoking the software object resolver of its own type; and storing the special attributes of the software object separately in the basic data, wherein the special attributes are type-exclusive attributes, including the network interface attribute of the network global variable.

[0112] The symbol table construction process includes: parsing the dependencies and subordination relationships of each software object in the information summary table; generating a unique symbol for each software object, which includes standard information fields and personalized information fields; performing differential parsing on the personalized information fields based on the software object type, wherein the standard information fields include data types and initial values, and the personalized information fields include variable storage areas and constant identifiers.

[0113] The namespace hierarchy rule for recursive matching is as follows: when a match fails, it proceeds to the parent namespace until the root namespace; when a match succeeds, it returns the data type, initial value, constant identifier, and region information of the variable.

[0114] The information summary table is transmitted in the form of a download target object, which is generated by data encapsulation of the control application to be downloaded and the information summary table.

[0115] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0116] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for organizing and acquiring real data in a PLC, characterized in that, include: Step 1: When the host computer performs the download operation, the software object of the control application to be downloaded is serialized to generate an information summary table. The information summary table includes the software object name, dependency relationship, fingerprint identifier, monitoring information and basic data. The information summary table and the control application to be downloaded are downloaded together to the lower computer PLC for storage. Step 2: When the host computer is monitoring online, it obtains the information summary table from the slave computer and serializes it to construct a symbol table; Step 3: The host computer obtains the actual program data of the lower computer by querying the symbol table. When the requested variable name is not the fully qualified name, recursive matching is performed according to the namespace hierarchy: first, the variables inside the current program unit are matched, then the variables in the same namespace are matched, and finally the global variables are matched.

2. The method for organizing and acquiring real data in a PLC according to claim 1, characterized in that, The serialization-generated information summary table includes: For software objects containing variable members, the variable object resolver and the software object type resolver are invoked in parallel. For software objects without variable members, only the software object resolver of its own type is invoked; The special attributes of software objects are stored separately in the basic data. These special attributes are type-exclusive attributes, including the network interface attributes of network global variables.

3. The method for organizing and acquiring real data in a PLC according to claim 1, characterized in that, The symbol table construction process includes: Analyze the dependencies and subordination relationships of each software object in the summary information table; Generate a unique symbol for each software object, which contains both standard information fields and personalized information fields; The personalized information fields are parsed based on the software object type. The standard information fields include data type and initial value, while the personalized information fields include variable storage area and constant identifier.

4. The method for organizing and acquiring real data in a PLC according to claim 1, characterized in that, The namespace hierarchy rule for recursive matching is as follows: When a match fails, the process proceeds to the parent namespace, up to the root namespace. When a match is successful, the variable's data type, initial value, constant identifier, and region information are returned.

5. The method for organizing and acquiring real data in a PLC according to claim 1, characterized in that, The information summary table is transmitted in the form of a download target object, which is generated by data encapsulation of the control application to be downloaded and the information summary table.

6. A system for organizing and acquiring real data in a PLC, characterized in that, include: Module M1: When the host computer performs the download operation, it serializes the software object of the control application to be downloaded to generate an information summary table. The information summary table includes the software object name, dependency relationship, fingerprint identifier, monitoring information and basic data. The information summary table and the control application to be downloaded are downloaded together to the lower computer PLC for storage. Module M2: When the host computer is monitoring online, it obtains the information summary table from the slave computer and serializes it to construct a symbol table; Module M3: The host computer obtains the actual program data of the lower computer by querying the symbol table. When the requested variable name is not the fully qualified name, recursive matching is performed according to the namespace hierarchy: first, variables within the current program unit are matched, then variables in the same namespace are matched, and finally global variables are matched.

7. The information organization and acquisition system for real data in a PLC according to claim 6, characterized in that, The serialization-generated information summary table includes: For software objects containing variable members, the variable object resolver and the software object type resolver are invoked in parallel. For software objects without variable members, only the software object resolver of its own type is invoked; The special attributes of software objects are stored separately in the basic data. These special attributes are type-exclusive attributes, including the network interface attributes of network global variables.

8. The information organization and acquisition system for real data in a PLC according to claim 6, characterized in that, The symbol table construction process includes: Analyze the dependencies and subordination relationships of each software object in the summary information table; Generate a unique symbol for each software object, which contains both standard information fields and personalized information fields; The personalized information fields are parsed based on the software object type. The standard information fields include data type and initial value, while the personalized information fields include variable storage area and constant identifier.

9. The information organization and acquisition system for real data in a PLC according to claim 6, characterized in that, The namespace hierarchy rule for recursive matching is as follows: When a match fails, the process proceeds to the parent namespace, up to the root namespace. When a match is successful, the variable's data type, initial value, constant identifier, and region information are returned.

10. The information organization and acquisition system for real data in a PLC according to claim 6, characterized in that, The information summary table is transmitted in the form of a download target object, which is generated by data encapsulation of the control application to be downloaded and the information summary table.

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