Motor_test not working

i need to test my drone before flyght.
For this target i tried to insert command motor_test in the mavlink console of nuttshel.
But although I enter the command “motor_test test 0 10” for test motor n.0 at 10% power the shell repond:

motor 0 set to 0.30
motor 0 set to 0.00

motor 7 set to 0.30
motor 7 set to 0.00

where am I wrong?

Thank’s to all