Accidentally i send some “not a number floats” over usart as current_setpoint.
Iam not quite sure what exactly happend then, but the brake resistor started to give off white smoke and heated up a lot. The drive is still functioning and i did NOT try to reproduce the problem. But i think, this behaviour is worth to be investigated by someone who owns some more oDrives than i do 
Hope, this report helps, Stephan