@giuliomoro thank you very much for the link. It was exactly what I was looking for.
The point-to-point communication via Ethernet for sending multiple trill devices data works properly now.
I followed these steps, the sequence may be useful to someone (but not sure if all of these steps were necessary):
1. Flash the Bela software last image to an SD card following: https://learn.bela.io/using-bela/bela-techniques/managing-your-sd-card/ (just to be sure to have installed the last version of the image)
2. then from terminal
ssh root@192.168.7.2
cd /etc/network
nano interfaces
- then set the following:
allow-hotplug eth0
iface eth0 inet static
address 192.168.10.2
netmask 255.255.255.0
network 192.168.10.0
- save with
ctrl+O
- close with
ctrl+X
3. then copy the Bela software to the eMMC following: https://learn.bela.io/using-bela/bela-techniques/managing-your-sd-card/
4. now (just for testing) run the example Communication / OSC from the IDE and change the remoteIp = "192.168.10.1";
5. set the same IP on your host PC