I tried the s7 node with your configuration and it worked perfectly ! The vendor of the chamber has talked about this s7 node one time but it was not clear at all. He used to talk about this Fetch/write protocol using the ports 2000 and 2001, create the frame, etc... I've never heard about this port 102 before you told me. I hope this topic will help other people in the future, because I've just spent 2 weeks for this...
Thank you !