Peter_n : I have to simulate many sensors including temperature, pressure, etc but I cannot use real sensors as the network is a bit complex so it is more ergonomic to use just one arduino that does it all.
dave-in-nj : That's exactly what I wan't to do ! The machine state seems very suitable for my problem thank you.
For now, I tried to change the Arduino address during runtime and it worked I just changed it using wire.begin() in the loop() function and tried to synchronise these modifications with the masters' demand so each time it asks an address the arduino has the same address in the same time.
Thank you all 