For small power, the ATV340 is more compact iwth smaller dimensions.
Regarding the functions, ATV340 is more machine oriented, has built in encoder card and few functions are different.
ATV900 is process oriented and has few pump functions (for pumps other than those with quadratic torque), for example it offers backspin control, sleep-wake up.
ATV340 has positioning by sensors - typical for machines. Also support synchronous motors in close loop.
Ethernet is built-in all ATV9xx but only in ATV340..E
ATV900 has wider accessories than ATV340
There is a plan to have positioning module in ATV340, so difference will be even greater.
Otherwise, today 95% of the functions are identical.
Regarding the functions, ATV340 is more machine oriented, has built in encoder card and few functions are different.
ATV900 is process oriented and has few pump functions (for pumps other than those with quadratic torque), for example it offers backspin control, sleep-wake up.
ATV340 has positioning by sensors - typical for machines. Also support synchronous motors in close loop.
Ethernet is built-in all ATV9xx but only in ATV340..E
ATV900 has wider accessories than ATV340
There is a plan to have positioning module in ATV340, so difference will be even greater.
Otherwise, today 95% of the functions are identical.