NodeId nodeId = new NodeId("ns=1;s=MyVariable");The above code creates a NodeId object with a string value of "ns=1;s=MyVariable". The string contains two parts: the namespace index and the identifier. The namespace index is the numeric index of the namespace in which the node resides. The identifier is a unique string identifier for the node within the namespace. Package Library: The NodeId class is part of the OPCFoundation.NetStandard.Opc.Ua.Core library, which is included in the OPC Foundation's .NET Standard reference stack. This library provides the core functionality for OPC UA clients and servers written in C#, including support for NodeIds, object modeling, and message generation and parsing.