problem on low setpoint cnc

hello.

I have used "hust cnc" on one of our machines.this machine has 2 axis.(x and z) axis x has a direct coupling(without gearbox and etc) to a servo motor which is controlled with "mige" servo drive.
the motor encoder is 2500 ppr.i set the drive on speed mode control.

my problem is that when i command the axis to move 1um the hmi show 1um movement but the axis doesn't move at all.
when i command the x axis to move for example 1mm there isn't any problem!

Does it mean in very low setpoint (from cnc to servo drive) the motor can not rotate the motor?

best regards.

Possibly.
Need more info on X axis. 2500 ppr isn't enough. Need ratio of X axis coupling to motor. Leadscrew? Linear drive? When you spec 'ppr' (pulses per revolution), I assume your motor is rotary.
Need leadscrew pitch.

hello.
thanks a lot for your reply.
yes,the motor is rotary and ball screw pitch is 10mm.
the motor has been connected to ball screw directly.
best regards.

2500 pulses per 10 millimeters.
250 pulses per millimeter.
.25 pulses per micron.
1 pulse per 4 microns.

There is a method to quadruple the resolution, but I don't know if the hust cnc hardware does this.