Unity3d as OPC Client

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

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.