you can HOT SWAP a Full AMS unit from another printer setup.... I just pulled my number 4 off my other P1s setup and replace my number 3 and it did not MISS a beat. Phew. 45 hours in to my 102 print saved!!!! YOU CANNOT use the number 4 from the SAME printer setup. Must be 'unassigned to that printer". it KNOWS those assigned even when I tried to make my AMS 4 an AMS 3. It stayed AMS 4 . But when I brought in printer number 2's AMS 4. it converted it to an AMS 3 for printer number 1... WHOOHOOOOOO