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07/13/2018
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Dear all,
I have a use case where I like to have an object which combines data lets say MES and also data from field.
For this purpose I am thinking about one server (address space) which will host MES data and views for client and another server – wrapper, which will provide data from PLC.
What I am still missing or I have not got yet is, how to create a variable with “input” reference to variable in another address space.
Or do I need implement it through subscription/read write, or views?
If you can direct or navigate me to point or example in UA-.NETStandard examples where can I learn that, I would be grateful.
Thank you
Rudo
05/30/2017
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It is not sure what you are expecting from this input.
The ExpandedNodeId allows you to reference nodes in other servers but that does not define any behavior.
To have input behavoir you would either need a client that reads from one server and writes to yours.
Or your server could be a client of the source server.
07/13/2018
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Hello Randy,
Thank you for answering.
My idea or expectation is to have nodes structure like Area->WorkCenter->Silo01. This will be on ServerA.
Silo01.MESQuantity – should be a float variable into which I will write a value most likely from DB in certain event.
Silo01.PCSQuantity – should be a float variable which value is ultimately going from PLC. For the reading of tags from PLC I am thinking about to use some kind of OPC UA Wrapper – ServerB.
So if I will go for “Or your server could be a client of the source server.” my ServerA needs to be a client for ServerB. I need to implement a read data change handler of monitored items in ServerB and somehow link them with variables at ServerA.
Does it seems reasonable to you? And is anywhere in any Annex a best practice of this kind of mechanism?
Thank you
BR Rudo
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