Determining angular position of a tape reel using timing based servo format
AssigneeInternational Business Machines Corporation
InventorMark Allan Taylor
Life of this patent
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Abstract
Provided are techniques for determining an angular position of a tape reel. A first edge of a hall sensor is identified. A number of format transitions on a timing based servo formatted tape are counted until detecting a predetermined edge of the hall sensor. A reel circumference is determined. A radius is determined using the determined reel circumference. A new circumference of a next revolution is determined using the determined radius and a tape thickness. A current angular position is determined using the determined new circumference and the counted format transitions.
Claims24
A computer-implemented method, comprising:
- identifying a first edge of a hall sensor, wherein the hall sensor changes state as poles of a motor pass by, and wherein there is an edge associated with each pole of the motor;
- counting a number of format transitions on a timing based servo formatted tape until detecting a predetermined edge of the hall sensor, wherein the predetermined edge is a number of edges after the first edge of the hall sensor, wherein a servo pattern is formed by servo tracks written on a tape medium, wherein the servo pattern consists of symbols including symbol A and symbol C, and wherein a format transition represents a transition from one symbol A to one symbol C or from one symbol C to one symbol A;
- determining a reel circumference;
- determining a radius using the determined reel circumference;
- determining a new circumference of a next revolution using the determined radius and a tape thickness;
- and
- determining a current angular position using the determined new circumference and the counted format transitions, wherein the current angular position is an amount of rotation from an origin of a tape reel.
A computer program product comprising a computer-readable storage medium storing a computer readable program, wherein the computer readable program when executed by a processor on a computer causes the computer to:
- identify a first edge of a hall sensor, wherein the hall sensor changes state as poles of a motor pass by, and wherein there is an edge associated with each pole of the motor;
- count a number of format transitions on a timing based servo formatted tape until detecting a predetermined edge of the hall sensor, wherein the predetermined edge is a number of edges after the first edge of the hall sensor, wherein a servo pattern is formed by servo tracks written on a tape medium, wherein the servo pattern consists of symbols including symbol A and symbol C, and wherein a format transition represents a transition from one symbol A to one symbol C or from one symbol C to one symbol A;
- determine a reel circumference using the counted format transitions;
- determine a radius using the determined reel circumference;
- determine a new circumference of a next revolution using the determined radius and a tape thickness;
- and
- determine a current angular position using the determined new circumference and the counted format transitions, wherein the current angular position is an amount of rotation from an origin of a tape reel.
A system, comprising:
- a processor;
- and
- hardware logic capable of performing operations, the operations comprising:
- identifying a first edge of a hall sensor, wherein the hall sensor changes state as poles of a motor pass by, and wherein there is an edge associated with each pole of the motor;
- counting a number of format transitions on a timing based servo formatted tape until detecting a predetermined edge of the hall sensor, wherein the predetermined edge is a number of edges after the first edge of the hall sensor, wherein a servo pattern is formed by servo tracks written on a tape medium, wherein the servo pattern consists of symbols including symbol A and symbol C, and wherein a format transition represents a transition from one symbol A to one symbol C or from one symbol C to one symbol A;
- determining a reel circumference using the counted format transitions;
- determining a radius using the determined reel circumference;
- determining a new circumference of a next revolution using the determined radius and a tape thickness;
- and
- determining a current angular position using the determined new circumference and the counted format transitions, wherein the current angular position is an amount of rotation from an origin of a tape reel.
Dependencies are inferred from the claim text.