Indirect access of nodes

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guolin
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Indirect access of nodes

Post by guolin »

Hi,
I have a question for the UA possbility. There are two ObjectTypes created in the same namespace: ObjectTypeA and ObjectTypeB. ObjectTypeA have a method component: MethodA and a variable component: VariableA. ObjectTypeB have a variable component :VariableB. VariableB is a data source of VariableA.
In this condition, UA client can access the value of VariableA by calling the MethodA with addressing informations of VariableB as input parameter, where MethodA reads value of VariableB then writes to VariableA. Current UA has such a capability?

If yes, the extension questions are : 1, how about MethodA subscribe the values of VariableB? 2, how about ObjectA and ObjectB are in different namespaces?

Thanks!

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Re: Indirect access of nodes

Post by Support Team »

Hi,

OPC UA objects, variables and methods are just the external representation of objects, data and operations in a system represented by the OPC UA server.

The business logic behind methods and variables is completely server specific and not defined by OPC UA. This is also completely independent of the namespaces the nodes are defined in.

Best Regards,
Unified Automation Support Team

guolin
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Re: Indirect access of nodes

Post by guolin »

Thanks!

Now the quesiton will be that is there any API available in current SDK toolkit , which can be called by a method of current object node to access any values of any other existing nodes ?

The logic of the method could be static. The source and destination of the logic is expected to be dynamic. so the method should has capabilities to access other node within the server scope.

I hope I descripe my question clearly.

Regards,
Guolin

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