Viesturs Lācis wrote: > I had a thought about that and there is one BUT... I am going to use > stepper motor to control the rotary axis and as far as i know there is > only one way to create a closed loop system - EMC outputs PWM signal > and receives encoder data and then there has to be PWM-to-step signal > converter. > EMC can output whatever you want, it doesn't have to be PWM. The problem with closed loop and steppers is that the available torque of a stepper decreases with speed, so when the motor falls behind enough for PID to try to correct, it's already lost. The stepper has no extra torque to give in response to the "faster" command it gets, unlike a servo.
Closed loop monitoring of a stepper position, using that for following error detection, is perfectly reasonable and can be done with EMC2, without a hardware PWM-to-step converter. - Steve ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
