Applied Motion Products offer closed loop control features on all of our stepper drives, motors, and integrated products by utilizing incremental quadrature encoders mounted to the rear shaft of the step motor. Stepper drives with encoder feedback connectors can be married to double-shaft step motors with encoders pre-assembled for you. Integrated steppers are available with encoders built directly into the housing of the motor.
Adding an encoder to your stepper system greatly enhances performance by providing you with these closed-loop functions: Stall Detection and Stall Prevention.
Stall Detection notifies the user/system/machine as soon a motor stall occurs, eliminating the uncertainty of whether or not the motor reached its target position.
Stall Prevention actually eliminates stalls by dynamically controlling the stator current and speed of the motor to maintain torque in all situations. This enables otherwise impossible control schemes in stepper systems, such as torque-limited velocity control and torque-limited position control.