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OPC Server Group Deletion

Question asked by TimCarmichael Champion on Jan 12, 2016
Latest reply on Jan 18, 2016 by cramsey

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.