Z axis does not work in RDC6445G

1.Problem description:Ruida RDC6445G controller. Except for the Z axis, everything else seems to work. When the up and down arrow keys are pressed, the table will not move. The stepper motor makes noise, but the table does not move.
2.Solution:It should be caused by the wrong calculation of the step distance of the Z-axis motor; there is another possibility that the motor movement is opposite to the limit, so the motor does not move and makes noise.