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OPC UA Connector using changeable NamespaceID to create tags

Question asked by tarnold on Apr 22, 2019
Latest reply on Apr 30, 2019 by tarnold

We have installed National Instruments as an OPC UA Server.  Further we've been using the OSIsoft PI Connector for OPC UA to connect to this OPC UA server and bring data into PI.

An issue with a recent upgrade on the NI side resulted in an inability of any client to connect to the NI OPC UA server for several days.  In trying to work this out with NI, they've pointed to the following spec.

http://documentation.unified-automation.com/uasdkhp/1.0.0/html/_l2_ua_node_ids.html
Which states the server isn't allowed to change the namespace index so long as there is a valid connection but can change it if there is no connection (or if the server is rebooted) and that the client shouldn't rely on the namespace index since it is changeable.

However, it seems the OSIsoft PI connector is relying on the Namespace index portion of the node ID to create the tag id.  After a workaround was implemented on the NI, the namespace index from the OPC UA server changed (as is apparently allowed by the spec).  The OSisoft PI connector uses the namespace index automatically in the tag name so now we have an entirely new set of tags that differ only by namespace index.  The PI OPC UA documentation indicates I can't alter this information using the filter file.  Calls to OSIsoft support were discouraging regarding the feasibility of merging the data in the original tags with the data in the new tags.  Pointing my templates to the new tags got us functional with current data but history for these tags is effectively cut off.

Is there anyway to prevent this default behavior in the OSIsoft PI connector?  This is surely going to happen again.

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