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04/11/2018
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Greetings, everyone!
I am a Unity programmer, new to OPC UA, trying to implement OPC UA into our project.
Now with Unity & C#, I have been able to create basic working UA server and client on windows 10 platform, which means I can browse, monitor, read and write my UA server's content with my client.
One of our project's goal is to request XML files which documents some working procedure from our partner company's center system/UA server, which is monitoring packaging machines. In the envisaged working environment, our devices (with UA client installed) will be in the same shop floor with the server.
I am new to the OPC UA field, and haven't been able to make direct contact with the partner company's programmer. Although I have read the Part 6 specifications and some other articles, I am still not sure about how normally people in packaging industry would do, when requesting or moving XML files between UA servers and clients. My questions are:
1) how should I request the XML file? To read from a node, or call a method node?
2) what is the most common way of transporting XML file between UA server and client? It doesn't have to be from packaging Industry.
The methods I can think of are through a) array of strings, b) array of XmlElements, c) ExtensionObject or d) http web service.
3) If our device also need to move similar size of XML files back to the server/center system, should we also create a UA server installed on our device, and have the center system create a client and request for it?
Thank you in advance!
Yi
05/30/2017
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You should look at the File ObjectType and the FileTransfer ObjectType defined in Part 5.
04/11/2018
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Thank you, that is what I am looking for!
04/11/2018
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Hi, from the Specification Part 5, I found the definitions of FileType and FileDirectoryType, and wrote a server with such structure to test.
Here are my questions:
1, Is the File1 shown in the picture the correct form of a FileType?
2, The methods shown are just void ones, should I implement the Open, Close, Write, Read, getPosition and SetPosition methods by myself, or are there other UA's APIs I don't know about that can implement these methods?
3, Where can I find some example code of how the FileType node could be created or used?
Thanks!
05/30/2017
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1) Looks right.
2) You need to implement the methods using mechanisms defined in the SDK you are using. How methods are implemented within a server is not mandated by the specification. Note that some SDKs have help APIs that completely implement the file type. Consult with the vendor/github repo which is source of your sdk.
04/11/2018
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I am using the Foundation's SDK. I have searched every source code from Foundation's SDK, didn't find any method or class that was operating the FileType.
This may seem silly to ask, to implement the FileType nodes, where should I look up the mechanisms defined by Foundation's SDK?
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