close loop whit stepper motor

Hello;
is possible that we building closed loop controller with stepper motor at the software ?

Short answer yes.

Long answer depends on what equipment is used and what machine quality it's going on. Are you talking about a closed loop steoper system where the drive outputs encoder signals after it uses them to control the motor variables? Or dumb stepper motor and drive and a separate encoder straight to Linuxcnc?

To help you will need to provide more specific information. Both are possible but what result are you looking for?

thanks for your reply ;
i want connect encoder output straightly to the linuxcnc and create closed loop feedback at the software not at the drive

Yes this can be done. The changes from a normal stepper motor setup is to
add the encoder input, take the position feedback from the encoder
and then start tuning the PID parameters.