We are experiencing an ongoing issue with a vendor based OPC server, so, I'm looking to the community for some possible answers.
A client has a connection to an OPC server, has created one or more groups and has populated the groups with a list of data points.
When the client disconnects 'cleanly', the OPC server should receive group deletion requests; they may, or may not, be acted upon.
If the client disconnects abruptly (ie: loss of network, loss of power, etc), the OPC server will not receive a group deletion request.
As per the vendor, it is the clients responsibility to request group deletion REGARDLESS of the shutdown reason (clean/abrupt).
If the client does not delete the groups, the OPC server creates a new group and leaves the old one(s) orphaned.
We saw the OPC server with no network connection maintaining groups for a client that had disconnected.
So... from a technical/standards perspective, what should happen?
Is the client required to delete groups that they may not know about?
Is the server supposed to detect a loss of connection and delete orphaned groups?
If possible, provide a link to a standard if you can find it, or post the relevant passage here.