Abstract: In one embodiment, a method includes updating a standard deviation or a variance based on a current position error signal sample, where a smoothing factor applied to a subsequent calculation of the standard deviation or variance is dynamically altered based at least in part on whether a current value of the standard deviation or the variance is above or below a specified value. A determination is made as to whether the standard deviation or the variance exceeds a predetermined threshold. A stopwrite threshold is determined based on the standard deviation or the variance when the standard deviation or the variance exceeds the predetermined threshold. A determination is made as to whether the current position error signal sample exceeds the stopwrite threshold. Writing is disabled when the current position error signal sample exceeds the stopwrite threshold. Writing is enabled when the current position error signal sample does not exceed the stopwrite threshold.

Abstract: Provided are a computer program product, system, and method for determining a skew error signal (SES) offset used to determine an SES to adjust heads in a drive unit. A determination is made of a first difference in a first orientation with respect to a direction of movement of the recordable storage media based on first and second position information read by first and second servo read elements on a first head. A determination is made of a second difference in a second orientation with respect to the direction of movement of the recordable storage media based on third and fourth position information read by the first servo read element and a third servo read element on a second head. An offset, calculated based on the determined first and second difference, is used to generate an error signal to adjust the first and second heads.

Abstract: Aspects of the present invention relate to an apparatus and corresponding method that includes transitioning from a monitor state to a stop write state when a determined position error is greater than a threshold error value for a first predetermined period, and transitioning from the monitor state to a write state when the determined position error is less than the threshold error value for a second predetermined period. Write operations are enabled and signals are provided to operate an actuator to translate a magnetic head laterally in a manner to reduce the determined position error while in the write state. Write operations are disabled and signals are provided to operate the actuator to translate the magnetic head laterally in a manner to reduce the determined position error while in the monitor state. Write operations are disabled while in the stop write state.

Abstract: A method according to one embodiment includes detecting a signal originating from at least one reader of a first outer module of a head as a tape passes thereacross, the head having at least the first outer module and a second outer modules positioned on opposite sides of an inner module and aligned with the inner module in a direction of tape travel thereacross. A first guide positioned in front of the first outer module is moved in a direction towards the tape until the signal detected by the first outer module decreases. The first guide is moved in a direction away from the tape to a position to set about a predetermined wrap angle of the tape relative to the first outer module after the signal detected by the first outer module decreases.

Abstract: In one embodiment, a tape drive system includes a magnetic head having at least one servo sensor for track-following at least one defined servo track of a longitudinal tape, a tape motion controller configured to move the longitudinal tape past the magnetic head, a compound actuator configured to translate the magnetic head laterally with respect to the longitudinal tape, and a control configured to track-follow the at least one defined servo track by reducing a position error between the magnetic head and a desired position, transition from a write state to a monitor state when the position error is greater than a threshold, transition from the monitor state to a stop write state when the position error is greater than the threshold for a first period, and transition from the monitor state to the write state when the position error is less than the threshold for a second period.

Abstract: In one embodiment, a data storage system includes a head; a drive mechanism for passing a medium over the head; a controller electrically coupled to the head; logic encoded in or available to the controller for: periodically determining a stopwrite threshold based on a standard deviation or a variance at a current position error signal sample, wherein a smoothing factor applied to a subsequent calculation of the standard deviation or variance is altered based at least in part on a current magnitude of the standard deviation or the variance; determining whether the current position error signal sample exceeds the stopwrite threshold; disabling writing when the current position error signal sample exceeds the stopwrite threshold; and enabling writing when the current position error signal sample does not exceed the stopwrite threshold. Other systems, methods, and computer program products are described according to more embodiments.

Abstract: A servo system according to one embodiment includes a servo control configured to: determine position error between a magnetic head and a desired position related to at least one defined servo track on a longitudinal tape based on at least one servo signal; calculate a first average position of the magnetic head while the longitudinal tape is moved in a first direction; calculate a first offset of the magnetic head while the longitudinal tape is moved in the first direction based on a target position and an assumption that the first average position of the magnetic head occurred when the tape was at a top-most position or a bottom-most position of a supply reel; and operate an actuator to position the actuator substantially at the target position using the first offset and the first average position.

Abstract: Aspects of the present invention relate to an apparatus and corresponding method that includes transitioning from a monitor state to a stop write state when a determined position error is greater than a threshold error value for a first predetermined period, and transitioning from the monitor state to a write state when the determined position error is less than the threshold error value for a second predetermined period. Write operations are enabled and signals are provided to operate an actuator to translate a magnetic head laterally in a manner to reduce the determined position error while in the write state. Write operations are disabled and signals are provided to operate the actuator to translate the magnetic head laterally in a manner to reduce the determined position error while in the monitor state. Write operations are disabled while in the stop write state.

Abstract: A method according to one embodiment includes receiving or determining primary velocity based on at least c of reading information encoded on a magnetic tape and a parameter associated with a motor of a drive mechanism. At a switching point, a reference velocity is made about equal to the primary velocity. After the switching point, the reference velocity is determined at various intervals. Also after the switching point, a value representative of a difference between the reference velocity and the primary velocity is determined, and a speed of the motor of the drive mechanism is adjusted for minimizing the difference between the reference velocity and the primary velocity. A system according to one embodiment includes a controller for controlling a drive mechanism, the controller being configured to perform the foregoing method.

Abstract: According to one embodiment, a method includes sensing a first servo sensor while a longitudinal tape is moved in a first direction; determining position error between the magnetic head and a desired position related to the at least one defined servo track; providing signals to operate a fine actuator to translate the magnetic head laterally in a manner to reduce the determined position error; calculating a first average position of the magnetic head for at least one first run-out cycle while the longitudinal tape is moved in the first direction; calculating a first offset of the magnetic head while the longitudinal tape is moved in the first direction; operating a coarse actuator to position the coarse actuator substantially at a target position using the first offset and the first average position.

Abstract: In one embodiment, a system includes a controller configured to: determine a reference velocity at various intervals, receive or determine a secondary velocity based at least in part on a parameter associated with a drive mechanism motor, determine a value representative of a difference between the reference velocity and secondary velocity, adjust a speed of the motor of the drive mechanism for minimizing the difference between the reference velocity and secondary velocity, receive/determine a primary velocity based on reading information encoded on a magnetic tape, at a switching point, make the reference velocity about equal to the primary velocity, after the switching point, determine the reference velocity at various intervals, after the switching point, determine a value representative of a difference between the reference velocity and primary velocity, and adjust the speed of the motor of the drive mechanism for minimizing the difference between the reference velocity and primary velocity.

Abstract: In one embodiment, a system includes a controller configured to: determine a reference velocity at various intervals, receive or determine a secondary velocity based at least in part on a parameter associated with a drive mechanism motor, determine a value representative of a difference between the reference velocity and secondary velocity, adjust a speed of the motor of the drive mechanism for minimizing the difference between the reference velocity and secondary velocity, receive/determine a primary velocity based on reading information encoded on a magnetic tape, at a switching point, make the reference velocity about equal to the primary velocity, after the switching point, determine the reference velocity at various intervals, after the switching point, determine a value representative of a difference between the reference velocity and primary velocity, and adjust the speed of the motor of the drive mechanism for minimizing the difference between the reference velocity and primary velocity.

Abstract: A servo track has servo pattern frames including two pairs of parallel transitions, the transitions of each pair spaced apart an equal distance, the first pair at an azimuth angle, the second pair at the opposite azimuth angle. A servo channel receives signals at first times corresponding to a servo read head detecting the transitions of the first pair of parallel transitions of a servo pattern frame, and second times corresponding to the servo read head detecting the transitions of the second pair of parallel transitions. The servo channel determines a relative lateral movement and velocity between the tape and the tape head based on respective functions of the ratio (TD?TC)/(TB?TA), distance d, and constants proportional to the azimuth angle and the trajectory angle.

Abstract: In a method for operating a tape storage device comprising a tape head for reading and/or writing data from/to a tape in the tape storage device, a first tape skew value concerning a skew of the tape is determined and the first tape skew value is converted into a first skew control signal by means of a skew feedback controller. A second tape skew value concerning the skew of the tape is determined, and the second tape skew value is converted into a second skew control signal by means of feed-forward controller. At least one compensation signal for the second skew control signal is determined, and at least one of a rotational orientation of the tape head and a tape motion direction of the tape is controlled dependent on the second skew control signal and the compensation signal in case the first skew control signal fails.

Abstract: A servo track has identical servo pattern frames including two pairs of parallel magnetic transitions, the transitions of each pair spaced apart an equal distance, the transitions of the first pair at an azimuth angle to the longitudinal axis of the tape, the transitions of the second pair at an opposite azimuth angle. A servo channel receives signals at first times corresponding to when a servo read head detects the first and second transitions of the first pair of parallel transitions of a servo pattern frame, and second times corresponding to when the servo read head detects the first and second transitions of the second pair of parallel transitions. The servo channel determines a relative lateral movement and velocity between the tape and the tape head based on the azimuth angle and the ratio of the difference of the first and the difference of the second times.

Abstract: In one embodiment, a data storage system includes a head; a drive mechanism for passing a medium over the head; a controller electrically coupled to the head; logic encoded in or available to the controller for: periodically determining a stopwrite threshold based on a standard deviation or a variance at a current position error signal sample, wherein a smoothing factor applied to a subsequent calculation of the standard deviation or variance is altered based at least in part on a current magnitude of the standard deviation or the variance; determining whether the current position error signal sample exceeds the stopwrite threshold; disabling writing when the current position error signal sample exceeds the stopwrite threshold; and enabling writing when the current position error signal sample does not exceed the stopwrite threshold. Other systems, methods, and computer program products are described according to more embodiments.

Abstract: Provided are a computer program product, system, and method for determining a skew error signal (SES) offset used to determine an SES to adjust heads in a drive unit. A determination is made of a first difference in a first orientation with respect to a direction of movement of the recordable storage media based on first and second position information read by first and second servo read elements on a first head. A determination is made of a second difference in a second orientation with respect to the direction of movement of the recordable storage media based on third and fourth position information read by the first servo read element and a third servo read element on a second head. An offset, calculated based on the determined first and second difference, is used to generate an error signal to adjust the first and second heads.

Abstract: A servo track has identical servo pattern frames including two pairs of parallel magnetic transitions, the transitions of each pair spaced apart an equal distance, the transitions of the first pair at an azimuth angle to the longitudinal axis of the tape, the transitions of the second pair at an opposite azimuth angle. A servo channel receives signals at first times corresponding to when a servo read head detects the first and second transitions of the first pair of parallel transitions of a servo pattern frame, and second times corresponding to when the servo read head detects the first and second transitions of the second pair of parallel transitions. The servo channel determines a relative lateral movement and velocity between the tape and the tape head based on the azimuth angle and the ratio of the difference of the first and the difference of the second times.

Abstract: A tape drive configured to accurately position a head actuator in the presence of physical disturbances is disclosed. The tape drive includes a track-follow controller to position a head actuator over data tracks on magnetic tape. The tape drive further includes a disturbance observer configured to estimate a vibration disturbance and output a compensation signal to assist the track-follow controller to accurately position the head actuator over the data tracks in the presence of vibration. When estimating the vibration disturbance, the disturbance observer takes into account vibration frequency characteristics, such as frequency characteristics derived from a vibration specification associated with the tape drive, or frequency characteristics derived from known vibration disturbances experienced by the tape drive. A corresponding method is also disclosed.

Abstract: A tape drive system according to one embodiment includes a magnetic head having at least one servo sensor; a tape motion controller; a fine actuator; a skew actuator; a coarse actuator; and a control. The control is configured to perform various operations that help account for vibrations that effect track-following a servo track when operating a tape drive. Additional systems, methods and computer program products are also described.