one more question for my global comprehension of the behaviour:
we see that, when discovering ignition OPCUA namespaces, the one that indexes Devices (ns=1) is only showing the “top” folder for each connected device.
Then, if we want to access one specific address inside the PLC, we have to prefix it with [device_name_in_ignition_module]
so my question are :
what is the orientation taken by IA for the OPCUA module to access Siemens’s PLC adresses?
Is it by building the namespace with ALL available NodeIds (taken from PLC’s DataBlocks,IOs,Flags, etc.) of the declared/connected PLCs (eg: S300)? and if so, how are managed Hardware bloc extensions (DIO,AIO, etc.)?
or is there a sort of “only one” nodeID (eg: S300) that has a special parsing gateway or feature that extracts the address prior to send it to S7 channel ?
thanks in advance for any info you can share on that 
Eric