Configuration

Note:

Before starting configuration, a new module instance must first be created. Click here for more information about creating Module instances.

Module Configuration

Once a new OPC UA Server module instance is created, users can configure different parameters to establish how connections to the server should be made. Below you will find a brief explanation of what each of these parameters mean and how to configure them:

Server

Server capabilities

Store & Forward

Additional endpoints

Additional endpoints lets you expose the OPC UA Server through more than one listening endpoint, each with its own network binding and security configuration. This is useful when the same server needs to be reached over different network interfaces or ports — for example, an insecure endpoint on localhost for local tools and a secured endpoint on a public interface for remote clients — without running a second module instance.

To add one, click on the button to the right of Additional endpoints and select New Endpoint. Each endpoint is configured independently and offers the same connection parameters as the main endpoint:

Access

In this area, you will assign the corresponding permissions to the Roles previously created in the Roles section.

Parameters:

Node permissions

Tag permissions

Tag access

Note:

It is mandatory to add a filter even when the whole model is going to be exposed.

Certificates

Once the module is running, whenever a client connects with a secure connection (different from None/None), the server will receive the client's certificate. By default, any certificate received is Rejected in N3uron and therefore, must be manually trusted in order to be able to establish the connection. For those clients that by default reject certificates sent by the server, manual approval of the certificate on the client side will also be necessary.

Methods

The OPC UA Server module allows users to define methods along with their input and output arguments. These methods enable users to execute custom logic in the N3uron node by calling a script previously created in Scripting. Each method can have zero or more input and output parameters, which support a variety of data types and value ranks. When a method is defined, it will be available in the _Node/Methods/METHOD_NAME node of the OPC UA Address Space.

Note:

In order to use Methods, it is necessary to run both a Scripting module and at least one external script that will be invoked by the method.

Note:

The return value of the script has to be an object whose keys are the names of the output arguments and its values are the output values. The value type must be coherent with the OPC UA types declared in the method definition.

Creating a method

To create a new method, expand the OPC UA Server module instance menu and select Methods. From the Model panel burger menu, select New Method.

N3uron version <1.22.4

N3uron version >=1.22.4

The method configuration settings contain the following options:

N3uron version <1.22.4

Once the corresponding script has been selected, the Input and Output arguments can be created if necessary. To do this, click either on the buttons to the right of Input arguments or Output arguments to add them, enter a description if you like, and select the corresponding settings for both the Data type and the Value rank fields.

Note:

The Method group (Module instance and Method name) is available from N3uron version 1.22.4. It generalizes the previous Scripting instance and Script name fields so that a method can target any compatible module instance. Existing method configurations remain fully compatible.

From version 1.22.4, the target method is configured under a Method group with the following fields:

The Input and Outputs arguments each expose a Description, a Data type (for example JSON String), and a Value rank (for example Scalar).

N3uron version >=1.22.4

Method groups

Note:

Method groups are available from N3uron version 1.22.4.

Methods can be organized into method groups (folders). Method groups let you group related methods together, creating a more organized and navigable method hierarchy within the OPC UA Address Space. To create one, expand the Methods menu in the Model panel and select New MethodGroup. Methods created inside a group are exposed under the corresponding folder in the _Node/Methods node.

Browse methods

Note:

The Browse methods action is available from N3uron version 1.22.4.

The Browse methods action lets you discover and inspect the methods available in this node and automatically create the corresponding OPC UA method definitions, instead of adding each one manually. Expand the Methods menu in the Model panel and select Browse methods to open the Select methods dialog.

Note:

For a script to appear in the Select methods dialog, the Scripting module instance must expose it as a named method. From N3uron version 1.22.4, external scripts in the Scripting module are exposed as named Methods: in the script Task, add an Action and set its Type to Method (Actions → Type → Method). Each script in that Task is then published as a named method (for example, ops_summary_daily or system_audit_node) that can be browsed and imported here.

In the Select methods dialog, the methods exposed by the running Scripting module instances are listed and organized by their group hierarchy. Select the check box next to each method you want to expose; the right-hand panel shows the selected method's details, including its Write flag and its Input and Output types. Click Apply to automatically create a method definition for each selected method.

Note:

Browse methods auto-creation handles the full Scripting type matrix, so all supported input and output argument types are correctly mapped when the methods are automatically generated.

Each generated method keeps the same group hierarchy it had in the Scripting module and is created with its Module instance, Method name, and Input and Output arguments already populated with the correct Data type and Value rank. After applying, remember to Save the configuration.