I bought a brand new Bachmann Plus HO B23-7 Union Pacific Diesel 156 in the box already set up with Digitrax DH123. My layout is set up for DC only. New loco won't do anything on powered track -- do I need to have a digital control unit to make some kind of modification to the programming so it will run on a DC system? I thought that this loco would run out of the box on either DCC or DC. Please help.