Unity3d as OPC Client

Question

I am trying to Connect to a OPC Server using Unity as client.

Has any experience with this?

My problem is that all the .NET OPC client Toolkits or SDK´s out there is either using .NET 4.0, running unmanaged code or using COM/DCOM.

Answer 1

Answer by jrs · Oct 07, 2015 at 12:31 PM

We ended up building a bridge (using python) that runs as a separate application and communicates with unity via osc or tcp

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feranti · Oct 07, 2015 at 12:41 PM 0

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Thank you for the answer. That's what I thought...

Answer 2

Answer by Wilbert-Blom · Jun 08, 2016 at 12:58 PM

If anybody has found a workable solution, paid or not, for reading (and writing) from an OPC server directly from (and to) Unity I would very much like to hear it!

So not through some separate application or tunnelling mechanism.

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Answer 3

Answer by feranti · Jun 08, 2016 at 03:55 PM

We also ended up to write a TCP bridge for several reason:

the OPC server we were trying to access to was running on a VM. Communication to an OPC server through network is a real pain as you have to modify your windows security settings, as far as I remember
Unity is stick to .NET 2.0 (and even a .NET 2.0 subset according your target) and most OPC library are using further .NET versions. Except if you want to rewrite an OPC library from scratch without these .NET requirements, you are quite fucked up there.

So we have developped a simple TCP bridge between Unity and the OPC server. We used the very easy to use OPCDANET library from Advosol (sorry for the ad but the question refers to an eventual paid solution).

Hope it helps

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feranti · Jun 23, 2017 at 09:07 AM 0

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Further information: The bridge is a TCP client-server running on the V$$anonymous$$. It uses OPCDANET library to get data from the OPC server also running on the V$$anonymous$$. Unity connects on this bridge using TCP as client, then sends the tag it wants to retrieve. The bridge gets the data and transfer it back to Unity.

This way, you don't need to have a remote OPC access on the OPC server. That would need to lower windows security settings, as far as I read on the Internet, because of the very old OLE components used. TCP bridge garantees a reliable communication between Unity and the OPC server.

The pain with that scheme is that you have to create you own bytes message pattern with message ids so you can know which answer from the client answer to which request from Unity. You have to deal with data types you want to retrieve in OPC server in order to cast them back to the right type in Unity. And, of course, handle the TCB buffering : a message can be split in two successive TCP buffers. You must have a mecanism to include each message length in itself to ensure that it is complete and, if it is not, go find the rest of it in the next TCP buffer. Long story short. There is many lectures of that on Internet but it a thing to keep in mind if you deal with huge amount of data at the same time.

Answer 4

Answer by orudas · Oct 24, 2018 at 07:57 AM

I tried using the code from this source https://github.com/RobinFischer/OPC-UA_Unity , still no luck trying to connect to the OPC UA server.

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Unity3d as OPC Client

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