What is an OPCUA Client?

An OPC UA (OPC Unified Architecture) client is a software application or component that initiates communication with OPC UA servers to retrieve data, exchange information, or interact with industrial automation and control systems. OPC UA is a widely used standard in the industrial automation sector for enabling secure and reliable data communication between devices, systems, and software applications. Here are the key functions and characteristics of an OPC UA client:

1. Data Retrieval: OPC UA clients are used to request and retrieve data from OPC UA servers. This data can include real-time process data, historical data, alarms, events, and more. Clients can subscribe to data changes or make periodic requests for specific data points.

2. Interaction: OPC UA clients can interact with OPC UA servers to perform various tasks, such as reading and writing data, controlling processes, acknowledging alarms, and triggering events. This allows them to actively participate in industrial automation and control operations.

3. Visualization: OPC UA clients often provide a user interface for monitoring and visualizing data from OPC UA servers. These interfaces can be used by operators, engineers, and other users to gain insights into the industrial processes.

4. Configuration and Discovery: OPC UA clients can discover available OPC UA servers on the network and retrieve information about the server's capabilities and data structures. This discovery is essential for setting up connections and understanding what data is available.

5. Security: OPC UA clients support robust security mechanisms, including authentication, encryption, and access control. This ensures that data communication is secure and that only authorized clients can access sensitive information.

6. Platform Independence: OPC UA clients are designed to be platform-independent, meaning they can run on various operating systems and hardware. This flexibility is crucial for integrating with diverse industrial systems.

7. Scalability: OPC UA clients can be used in small-scale systems or large, complex industrial networks, making them versatile tools for industrial automation and control applications.

8. Redundancy: In mission-critical applications, OPC UA clients can be configured for redundancy, allowing them to automatically switch to backup servers in case of server failure, ensuring uninterrupted data access.

9. Compliance with Standards: OPC UA clients adhere to the OPC UA standard, which is maintained by the OPC Foundation. This standardization ensures interoperability between different OPC UA clients and servers from various vendors.

Overall, an OPC UA client plays a crucial role in connecting to and communicating with OPC UA servers, enabling data exchange and control in industrial automation systems. These clients are used in a wide range of industries, including manufacturing, energy, utilities, and more, to facilitate secure and efficient data communication between devices, software applications, and control systems.

Configuration

• Endpoint: The URL of the OPCUA server to connect to.

• Application Name: The name gateway device will use to identify itself to the OPCUA server.

• Security Mode: How the connection to the OPCUA server should be secured.

• Security Policy: What cryptographic functions should be used when securing the connection

• User Token Type: Whether or not to use an user to connect to OPCUA Server.

• User Name: The username to use if the “User Token Type” is “userName”

• Password: The password to use if the “User Token Type” is “userName”

• Certificate Root Folder: The folder to use to store and manage certificates from. This can be helpful if you do not have access to the default folder that openSSL will use to store certificates.

Functions

Read

Read a value of a node in an OPCUA server.

Write

Write a value to a node in an OPCUA server.

Browse

Browse to see what nodes are children of a given node. If a node is not provided children of the root node will be given.

Testing

Prosys OPC UA Simulation Server - 

OPC UA Simulation Server Request Download - Prosys OPC

The Prosys OPCUA server is be used to setup a quick and simple OPCUA server. Connection Address UA TCP can be used to connect to the server.

The Address Space tab will show you all of the nodes and node ids that can be used for reading.

 

Ignition Maker - 

Ignition Maker Edition | Inductive Automation

Ignition Maker can be installed locally without time limits like standard Ignition. You can configure the OPCUA server settings at ‘Config->Opcua->OPC UA Settings’

You can then connect to the server using localhost:<Binding Port>

There will be a few system tags that already exists but to create new test tags you will have to use the Igntion Designer