OPC UA Services The eUA Server provides these IEC 62541-4 compliant services to client applications: Discovery Secure channel Session Monitored item and subscription Reverse Connect (from firmware 2022.9 or newer) Firmware Update with OPC UA (from firmware 2022.0 LTS or newer) • Published/reviewed: 2026-04-02 ☃ Revision 092 • … Read More
Security This topic refers to the configuration of the OPC UA client regarding the security requirements when connecting to a remote OPC UA server. Supported user authentication The user of the OPC UA client can authenticate itself towards the remote OPC UA server using the following… Read More
OPC UA Historical Access (HA) Available from 2019.6 Standard OPC UA® HA enables the OPC UA® clients to access the historical data of the PLCnext Technology DataLogger. You can call selected variables from a database using OPC UA® HA. To use OPC UA® HA for the data of GDS variables, the variables must be present in at least one… Read More
OPC UA® monitored item and subscription An OPC UA® client can subscribe to a list of variables that are then monitored for changes by the GDS. The variables are checked for changes at a defined interval. When subscribing to a variable, the client can define a sample rate, which is then served by… Read More
Module configuration of the OPC UA client The OPC UA client can be configured in PLCnext Engineer from version 2023.3. We recommend to use PLCnext Engineer for the configuration (see also Tutorial – OPC UA setup for PLCnext Control). The configuration can also be performed using an additional… Read More
OPC UA session Creation The eUA server supports a limited amount of concurrent sessions depending on the controller type (Device-specific OPC UA settings). The server verifies the ClientCertificate for secure endpoints when creating a session. Make sure that the ApplicationURI specified in the ApplicationDescription matches the… Read More
Alias Names Available from 2022.6 The eUA Server supports Alias Names according to the OPC UA specification OPC 10000-17 – Part 17: Alias Names. The functionality of Alias Names is to reference one or multiple nodes in a server address space using a custom name. The eUA… Read More
Reverse Connect Available from firmware version 2022.9 What problem should be solved In some automation applications the PLCnext Control device is connected to the internet. In this case, a basic security requirement is to reduce the open ports to prevent attacks from the internet. The Reverse Connect… Read More
Configuration of the OPC UA® server with PLCnext Engineer You can configure the OPC UA® server with the software PLCnext Engineer. For more information about the configuration options refer to the section OPC UA Server in the Online Help of PLCnext Engineer. You can find the PLCnext Engineer Online Help within the software at the Help →… Read More
OPC UA client Available from 2023.0 LTS The OPC UA client supports subscribing variables from connected servers and writing changes of local variables to connected servers. The PLCnext Control device establishes the connection automatically as soon as the server is available. When the connection gets lost, the OPC UA… Read More
