Thank you
I already find that the correct combination is root/password.
But I thing Digi has a serious issue:
I bought 10 pieces from RS - so all them was NEW products. Nobody changed them, so I suposed that root/dbps should be the correct one.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Nowhere in the "official" documentation is mentioned that it could be another combination.
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
After I spent few hours searching on the net, finaly I find that there could be some other combination. One of them was root/password, which works.
I strongly sugest to Digi to make all necessary modification to their data sheets in order to help us to avoid loose time.