I just need to get 2 or a few skeleton segments for a contemporary dance performance, and this way, I will solve my problem temporarily. Xsens may not be a widely used system, but it works great. I think it deserves an Xsens to OSC converter PD object some day, But this  exceeds my programming skills (as you will get it from my code above :) ).

Just remembered now:

Xsens has a fps rate of 60-240 and a very big amount of data is transferred very fast over the network.  When I listened the packages with [netreceive] and printed them on the console, PD Vanilla 0.49.1 crashed. But it worked with Purr-data. Indeed, I didn't have time to test it in detail. Maybe the problem was with my computer. Just for info.

Thank you my friends.