Hi,

Different clients can do things differently. UaExpert might e.g. make a one-per-connection “internal” subscription for observing the server status. If you have the “Data Access View” in it open (which is most likely) that might make one even without any items (our Browser would do that as well). Our Browser application instead Reads the server status periodically (this is also one of the ways it detects connection breaks). Some other UaExpert views might also use a subscription.