I'm using the Unified Automation UACPPServer and the UAExpert Client to connect to it. I've also written .NET code with the SDK to get a list of all nodes from the server. While traversing the hierarchy in code, multiple nodes with duplicate NodeIDs have been found. I've confirmed this in using UAExpert. The image below shows one of the nodes. Both nodes called "ImageGIF" have the same NodeID. According to the UA spec, NodeIDs should be unique. There are ~14 duplicates NodeIDs in the hierarchy. Is this expected behavior? Am I looking at things incorrectly? Any help would be greatly appreciated.
in OPC UA, nodes are allowed to appear multiple times in the address space, as they can simply be referenced more than once by other nodes. This does not mean that the NodeIds are not unique, instead only the same node appears multiple times in the address space. This is intended by design and not unusual. It is also allowed for nodes not to be visible at all in the address space (i.e. not referenced at all by other nodes).
