Is there a replacement for the ECMA-C30804E7 Servomotor that is compatible with ASD-B2-0421-B?

There are two replacement motors that can work with the ASD-B2-0421-B servo drive that will mount and up fit and form in place of the ECMA-C30804E7:
ECMA-C10804R7 or ECMA-C20804R7 the “R” can be replaced by an “E”, “P” or a “G”.
Also the I/O interface (CN1) on the B2 –B is not the same as the older B-series you called out. Some rewiring has to be done. So it's better to get a Full Screw terminal brake out. THIS WILL NOT BE “PLUG-AND-PLAY” Parameters will need adjusting.

Motor and feedback cable connector ends (servo drive side) are different so these cables must be ordered too.
ASDBCAEN0005 - Encoder FB cable 5M
ASDBCAPW0205 - Motor power Cable 5M
ASD-MDDS4444 - I/O (CN1 screw Terminal I/F)