Patent ID: 6768281
Filing Date: 2004-07-27
Classification: G11B,H02P,Y10S

Abstract:
A verification system for a tape drive, said tape drive having a plurality of DC motors, said verification system comprising:a plurality of PWM motor drivers with DACs for operating said DC motors; a plurality of Hall sensors for sensing the states of said DC motors; and logic for operating said PWM motor drivers, and detecting said Hall sensors, said logic: operating said PWM motor drivers and verifying the on time duty cycle period and offset of said PWM motor drivers; operating said PWM motor drivers in DISABLE mode and verifying DAC current reference and amplifier sense signals against positive and negative thresholds; and operating said PWM motor drivers to rotate said DC motors in at least one direction, detecting said Hall sensors during said rotation, and verifying the Hall sensor state sequence of each of said DC motors for said at least one direction; and if said verification of said on time duty cycle period and offset for said PWM motor drivers, said verification of said DAC current reference and amplifier sense signals for said PWM motor drivers, and said Hall sensor state sequence for each of said DC motors, are all successful, operating said PWM motor drivers to rotate said DC motors; and accelerating said DC motors at desired torque, verifying time of acceleration of each of said DC motors to a desired velocity; verifying a computed velocity of each of said DC motors based on a measured velocity, to a reference velocity; and verifying an actual rotation rate of each of said DC motors to a computed velocity thereof.