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
How to integrate an external information model Note: This is an advanced topic which requires knowledge about OPC UA and XML file generation. In addition, some understanding of the tools UaExpert and UaModeler is required. This guide is based on the Process Automation Device Information Model (PA-DIM), a companion… Read More
OPC UA PubSub Available from firmware 2022.0 LTS on all PLCnext Control devices Configurable in PLCnext Engineer from software release 2022.0 LTS Starting with firmware 2022.0 LTS, the PLCnext Technology firmware has an implementation of the OPC UA® Publish and Subscribe specification (PubSub) as a new communication protocol. This enables the data exchange in a… 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 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
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
OPC UA discovery/connection options Note: The OPC UA client and server use the OpenSSL library to validate X.509 certificates using the OpenSSL flag X509_V_FLAG_X509_STRICT. As firmware 2024.0 LTS is updated to OpenSSL 3.0, the X.509 certificate validation became more strict, especially for non self-signed certificates. This may cause the server to return… Read More
Introduction to information models The PLCnext Technology eUA server provides these IEC 62541-5 compliant information models: External information models Alarms and conditions Device information Historical data access File access Global Data Space Common OPC UA terminology This topic describes some common OPC UA… Read More
Device-specific OPC UA® settings and limitations OPC UA server The PLCnext Technology controllers have the following device-specific default OPC UA® settings: Target Maximum number of sessions Minimum supported sample rate Available sample rates AXC F 1152 3 100 100, 250, 500, 1000, 2000, 5000 AXC F 2152… 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
