Getting into the specifics of leased tags on this one. I have a UDT with tags in driven scan classes and others (SQL query tags) in leased scan classes. A couple of the driven scan class tags are used to show equipment state in templates on an overview window. Our templates use indirect tag bindings and/or expressions to access these status tags within the UDT instances. The question is, does opening the overview window, and therefore accessing these equipment state tags, trigger the gateway to execute the leased tags of the UDT instances?
We’re trying to hunt down reasons for slow window loading, and I’m trying to eliminate these leased SQL query tags as a source of the problem.
Leased scan classes change to the leased/driven rate when a subscription is allocated to any Vision or Perspective window/template/view in 8.x versions of Ignition. This includes opening a the window/template/view in the Designer.
In 7.x versions the same applies, plus any subscriptions via the Tag Browse tree in the Designer.
Thanks for the clarification. You’ll have to forgive me because I’m going to belabor the point a little more.
Like I mentioned, our templates pull status information from a UDT instance, kind of like my attached example, using expressions or indirect tag references. We are passing the tag path of the UDT instance to the template as a template parameter, then resolving the path to the actual opc tags within the UDT using the expression/indirect tag. We don’t bind the UDT instance itself to the template. Does this scenario still cause the leased SQL query tag to start executing when we open a window that contains these templates?
Sorry for the delayed response. That is correct, in 8.x versions of Ignition tags will not become leased when viewed within the Designer’s Tag Browse tree. For the lease to trigger within the Designer, you would need to open a view/window that contained a binding to that specific tag.
