OPC XML-DA does not identify OPC items by a single string as OPC COM. Instead, it uses an additional string, and only the combination of the two identifies an item in an OPC XML-DA server. The original string that roughly corresponds to OPC item ID is called “ItemName” in the OPC XML-DA specification; in QuickOPC, we use the existing ItemId property for it. The additional string is called “ItemPath” in the OPC XML-DA specification; in QuickOPC, we have introduced a NodePath property for it. This property appears both in the DANodeDescriptor and DANodeElement. When you use the information received from the OPC XML browsing, both ItemId and NodePath are filled in the DANodeElement, and you can easily convert it to a DANodeDescriptor and it will “just work”. If you are getting the nodes (items) from elsewhere, you need to create a DANodeDescriptor that contains both these strings (at least in general case; some OPC XML-DA server do not use them both).