Stepper Motor Settling Time (Ringing) and Resonance
When the stepper motor wholesale receives the final pulse signal, (either one or from a continuous train), it will stop rotating. However, complete rest will not occur until all the oscillations have stopped. The time it takes from the application of the last pulse received until the stepper motor comes to a complete rest is known as settling time. (See graph below).

Resonance Characteristics
Since a stepper motor system is a discreet increment positioning system, it is subject to the effect of resonance. Where the system is operated at this given frequency, it may begin oscillating. The primary resonance frequency occurs at about one revolution per second. Oscillating will cause a loss of effective torque and may result in a loss of synchronism. Settling time and resonance can be best dealt with by dampening the stepper motor's oscillations through mechanical means. Mechanically, a friction or viscous damper may be mounted on the stepper motor to smooth out the desired motion.

Methods for Changing or Reducing Resonance Points:
• Use of Gearboxes or Pulley Ratios
• Utilize Microstep Drive Techniques
• Change System Inertia
• Accelerate Through Resonance Speed Ranges
• Correct Coupling Compliance

Stepper motor with encoder
Although stepper motors do not require an encoder, Anaheim Automation's double-ended shaft stepper motors are "encoder-ready" as standard construction. Encoders aid in determining whether or not the final position has been achieved. Anaheim Automation indexers contain electronics that allow position correction to be obtained. Although the standard incremental encoder provides 4,000 counts per shaft revolution, this does not limit the step resolution to 4,000. It does mean however, that if an encoder is being used for closed-loop positioning, a "deadband window" would exist. Therefore it is not possible to account for actual "in-between" microsteps.

Stepper Motor Driver Excitation Modes

PWM (Chopper) Stepper Motor Drivers – Microstep