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Method and device for reading and writing PLC variables through SQL database

A database and variable reading technology, applied in the field of PLC, can solve problems such as the limitation of client software development language, and achieve the effect of improving convenience and flexibility and reducing difficulty

Inactive Publication Date: 2018-04-06
深圳市合信自动化技术有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The problem with this method is that users need to develop the OPC client protocol, requiring them to have strong technical strength, and there are also restrictions on the development language of client software.

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  • Method and device for reading and writing PLC variables through SQL database
  • Method and device for reading and writing PLC variables through SQL database
  • Method and device for reading and writing PLC variables through SQL database

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Embodiment Construction

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0040] Here, it should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only the structures and / or processing steps closely related to the solution according to the present invention are shown in the drawings, and the related Other details are not relevant to the invention.

[0041] Such as figure 1 As shown, a schematic diagram of the main flow of an embodiment of a method for reading and writing...

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Abstract

The embodiment of the invention discloses a method for reading and writing PLC variables through an SQL database. The method includes the steps of establishing a corresponding relation between variable groups in a PLC device and SQL database tables through user configuration, wherein each variable group corresponds to one read variable data table in the SQL database; establishing connection with each PLC device in the user configuration; periodically reading the value of each variable group in each PLC device in the user configuration, and updating the value of each variable group into the read variable data table corresponding to each corresponding variable group; creating a write variable data table, inserting an update record into the write variable data table, and writing the write variable value in the update record into the corresponding PLC device, to replace the original variable value of the variable group in the PLC device. The invention further discloses a corresponding device. By implementing the method and device, the difficulty of developing superior monitoring software is reduced.

Description

technical field [0001] The invention relates to the field of PLC, in particular to a method and a device for reading and writing PLC variables through an SQL database. Background technique [0002] In the industrial control industry, users often need to develop host computer monitoring software to monitor on-site production conditions. The host computer needs to communicate with the main control PLC through the host computer monitoring software to read and write its memory. However, PLC supports a variety of communication protocols, some of which are not public, and it is very difficult to develop drivers. Therefore, PLC manufacturers provide their own OPC Servers, which realize the memory reading and writing of their own PLCs, and provide open standard OPC interfaces for support. The third-party software interconnection of OPC client. Among them, OPC (OLE for Process Control) is a protocol that uses Microsoft's COM / DCOM technology to achieve automatic control; OPC Server / C...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F17/30
CPCG06F16/2291
Inventor 刘胜红王桥生
Owner 深圳市合信自动化技术有限公司