Ns=2;s= in front of OPC Item Path?


I set up a OPC-UA type connection in Ignition to connect to KEPServer EX V6. The previous configuration is OPC-DA COM connection to KEPServer EX V5.

However, now all the OPC tags need to have “ns=2;s=” as a prefix of their OPC Item Paths. The OPC tags would have “Config Error” without this prefix.

Has anyone encountered this and know what “ns=2;s=” mean? The Ignition version I’m using is 7.9.4.


When an OPC tag belongs to an OPC UA connection, the OPC Item Path is specifying the NodeId.

That prefix specifies the namespace index a NodeId belongs to.

For weird historical reasons, we assume ns=1 if it’s not explicitly present. Kepware’s Nodes are all in ns=2, so, it must be specified.

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