CESMII NodeSet Utilities

CESMII NodeSet Utilities is a set of .Net libraries for reading, validating, manipulating, and creating of OPC UA NodeSets. It is built on top of the OPC Foundation's OPCFoundation.NetStandard.Opc.Ua.Core library.

Getting Started

The easiest way to start using the nodeset utilites is to NuGet the following packages:

• NuGet: CESMII.OpcUa.NodeSetImporter
• NuGet: CESMII.OpcUa.NodeSetModel
• NuGet: CESMII.OpcUa.NodeSetModel.Factory.Opc

The using statements for the basic code snippets below are:

using CESMII.OpcUa.NodeSetModel;
using CESMII.OpcUa.NodeSetModel.Factory.Opc;
using Microsoft.Extensions.Logging.Abstractions;
using Opc.Ua;
using Opc.Ua.Export;

Parsing of Nodeset Files

The snippet below shows how to setup the nodeset utility's importer and parse a couple of OPC UA nodeset xml files.

// Location of nodeset xml files
var nodeSetDirectory = "NodeSets";

// Set up the importer
var importer = new UANodeSetModelImporter(NullLogger.Instance);
var nodeSetModels = new Dictionary<string, NodeSetModel>();
var opcContext = new DefaultOpcUaContext(nodeSetModels, NullLogger.Instance);

// Read and import the OPC UA nodeset
var file = Path.Combine(nodeSetDirectory, "opcfoundation.org.UA.NodeSet2.xml");
var nodeSet = UANodeSet.Read(new FileStream(file, FileMode.Open));
await importer.LoadNodeSetModelAsync(opcContext, nodeSet);
var uaBaseModel = baseNodeSetsDict[Namespaces.OpcUa];

// Read and import the OPC UA DI nodeset
file = Path.Combine(strTestNodeSetDirectory, "opcfoundation.org.UA.DI.NodeSet2.xml");
nodeSet = UANodeSet.Read(new FileStream(file, FileMode.Open));
await importer.LoadNodeSetModelAsync(opcContext, nodeSet);
var uaDiModel = nodeSetModels.Last();

// Output Object Types of the DI nodeset
Console.WriteLine($"DI Object Types:");
uaDiModel.Value.ObjectTypes.ForEach(aObjectTypeModel => {
    Console.WriteLine(aObjectTypeModel.DisplayName.First().Text);
});

Creating a New NodeSet

The code below shows how to create a new NodeSetModel and add it to our project.

// create new NodeSetModel and add it to dictionary of NodeSetModels
var nodeSetModel = new NodeSetModel
{
    ModelUri = "https://opcua.rocks/UA",
    RequiredModels = new List<RequiredModelInfo>
    {
        new RequiredModelInfo { 
            ModelUri= uaBaseModel.ModelUri, 
            PublicationDate = uaBaseModel.PublicationDate, 
            Version = uaBaseModel.Version
        }
    },
};
nodeSetModels.Add(nodeSetModel.ModelUri, nodeSetModel);

Adding an Object Type to the New NodeSet

Below we show how to create a type with a property and a variable and add it to our new NodeSetModel. Note, how DataTypes and SuperTypes are passed as objects, and how we make use of Engineering Units.

// a counter for new node id's
uint nextNodeId = 1000;

// a couple of dictionaries with OPC UA data and object types for convenience
var uaObjectTypes = uaBaseModel.ObjectTypes.ToDictionary(x => x.DisplayName.First().Text);
var uaDataTypes = uaBaseModel.DataTypes.ToDictionary(x => x.DisplayName.First().Text);

// the classic: Dr. Stefan Profanter's opcua.rocks animal type
var animalType = new ObjectTypeModel
{
    DisplayName = new List<NodeModel.LocalizedText> { "AnimalType" },
    BrowseName = "Animal Type",
    SymbolicName = "Animal Type",
    SuperType = uaObjectTypes["BaseObjectType"],
    NodeSet = nodeSetModel,
    NodeId = new ExpandedNodeId(nextNodeId++, nodeSetModel.ModelUri).ToString(),
    Properties = new List<VariableModel>
    {
        new PropertyModel
        {
            NodeSet = nodeSetModel,
            NodeId = new ExpandedNodeId(nextNodeId++, nodeSetModel.ModelUri).ToString(),
            DisplayName = new List<NodeModel.LocalizedText> { "Name" },
            DataType = uaDataTypes["String"],
        },
    },
    DataVariables = new List<DataVariableModel>
    {
        new DataVariableModel
        {
            NodeSet = nodeSetModel,
            NodeId = new ExpandedNodeId(nextNodeId++, nodeSetModel.ModelUri).ToString(),
            DisplayName = new List<NodeModel.LocalizedText> { "Height" },
            DataType = uaDataTypes["Float"],
            EngineeringUnit = new VariableModel.EngineeringUnitInfo { DisplayName = "metre"  },
        },
    },
};

nodeSetModel.ObjectTypes.Add(animalType);

Serialize a NodeSetModel to XML

The snippet below shows how to serialize a NodeSetModel as XML.

// validate all node2node references
nodeSetModel.UpdateIndices();

// create nodeset xml
var exportedNodeSetXml = UANodeSetModelExporter.ExportNodeSetAsXml(nodeSetModel, nodeSetModels);

Console.WriteLine(exportedNodeSetXml);

Next Steps

We need a bit more information about how to create and parse values.

A more complete write-up with a walk through example and further references can be found here.