Hi,
i am new to OPC UA development and trying to getting started. In my use case i've got a Database (OPC UA Server) which is continuously browsed by a Visualisation component (OPC UA Client).
In the case of only a few elements in the addresspace of the server this browsing solution works very well, but if there are > 500-1000 elements this browsing solution starts getting really slow.
A fact is, that most of the values i am browsing aren't changing, so using some kind of subscription function could be a possible solution to only get the changes. The problem is that i can't find some kind of "subscription to folders and all included elements" in the documentation of the SDK. Is this possible in OPC UA? Could you give me a hint how to realise this if it is possible?
Thanks in advance!
Subscription on folders?
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Re: Subscription on folders?
Hi,
MonitoredItems for data change notifications in a Subscription are created for individual variable nodes. It is not possible to create a subscription for a folder.
You must select the nodes of interest during browsing (using the NodeId) or load the NodeIds from a configuration file. The monitored items are then created with the NodeIds for the nodes of interest. The server will then deliver changed values only after delivering the current values for all added monitored items.
Best Regards,
Unified Automation Support Team
MonitoredItems for data change notifications in a Subscription are created for individual variable nodes. It is not possible to create a subscription for a folder.
You must select the nodes of interest during browsing (using the NodeId) or load the NodeIds from a configuration file. The monitored items are then created with the NodeIds for the nodes of interest. The server will then deliver changed values only after delivering the current values for all added monitored items.
Best Regards,
Unified Automation Support Team