Hi,

I assume your question to mean _all_ variables of a Server.

Is it possible to explain the use-case where you would need this?

Short/Easy answer:
Not possible in OPC UA and basically a workflow that would require this is not “the OPC UA way” of doing this.

Medium answer:
Technically there is the Query service call (https://reference.opcfoundation.org/Core/docs/Part4/5.9.3/), but I have not seen nor know a server that would support it. But this would be the most “OPC UA way” for this sort of an operation.

Long answer:
All nodes should be at the end of some hierarchical reference path from the Root node. Thus technically it is possible to do Browse operations repeatedly until you have seen all nodes. Note that the number of nodes can be theoretically infinite and the address space can contain loops. Compared to e.g. OPC Classic in OPC UA there is a lot of metadata thus there is a lot of nodes. It would be best to assume not all nodes fit into memory in a generic case.

Basically the only use-case for this kind of an operation would be e.g. an application that would try to export all the data of a server. Otherwise this kind of an operation can potentially last a very long time.

In general most cases should either be solvable by just checking some known Folder of the server e.g. in the DI companion specification it defines all devices should be discoverable from the ‘DeviceSet’ folder or subfolder.

Alternatively applications (such as our Browser) typically offer some sort of a tree view for the address space and lazily Browse the subnodes whenever user expands a node.