Thanks.. !! I'll look into that. I'm still in the design phase of everything so i'll look and see if there may be a another way of doing multi-material instead of directly form the duet. I know in interviews Prusa mentioned that they are using a arduino for the material handler so maybe I can do the same and use one of the data parts. I wanted to map each material in the changer as a tool and use the Tx command to switch between materials. this may still be possible as i haven't gotten all the way through the documentation. 🙂