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Example: OPC UA Client

Product: CODESYS OPC UA

This example shows how to use the IEC 61131-3 interface of the CODESYS OPC UA Client. It contains function blocks to connect to and exchange data with other OPC UA servers. It also includes two visualizations to operate the cited function blocks via a user interface and to check server certificates.

Description

The example contains a project with two applications: UAClientDemo and UAServerData.

The UAClientDemo application contains function blocks for using the CODESYS OPC UA client.

  • UAConnection: To establish the connection to any OPC UA Server

  • UABrowse: To send browse requests to an OPC UA Server

  • UASubscription: To generate OPC UA subscriptions

  • UAMonitoredItem: To monitor OPC UA variables (“Monitored Items”)

  • UAAttributes: To send read/write commands to the OPC UA Server

  • UAMethod: To call OPC UA methods

  • UAClient: State machine for the OPC UA Client to establish and terminate connections. The function block is the basis for the visualization.

The UAServerData application publishes a data set about the CODESYS OPC UA Server.

Additional information

The example contains two visualizations:

  • CheckCertificate provides a user interface to accept server certificates one time and then establish a secure connection. The CODESYS Security Agent can be used to permanently trust server certificates.

  • Visualization provides a user interface to operate the CODESYS OPC UA Client using the UAClient function block.

Important

  • The connection to OPC UA servers is possible only via an IP address and not a host name.

  • To establish secure server–client communication, the CODESYS Security Agent has to be used to generate a client certificate on the controller before the connection is established.

System requirements and restrictions

Programming system

CODESYS Development System (version 3.5.17.0 or higher)

Runtime system

CODESYS Control Win (version 3.5.17.0)

Add-on components

CmpOPCUAClient runtime system component

Note

_example_icon.png DOWNLOAD Project

After installing the package, you will find the sample project in the directory C:\Users\<user>\CODESYS Examples\OPC UA Client Example.

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