Timing-based track-following servo for linear tape systems

Barrett, R. C.; Klaassen, E.H.; Albrecht, T. R.; Jaquette, G. A.; Eaton, J.H.

doi:10.1109/20.706730

Cited by 50 publications

(13 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In linear tape systems, these servo patterns typically consist of magnetic transitions with two different azimuthal slopes (Barrett et al 1998). The lateral position of a head module is derived from the timing of pulses obtained from a servo element reading the servo patterns, with the servo elements typically being part of the head module.…”

Section: Introductionmentioning

confidence: 99%

LPOS symbol detection by soft-output combining of dual synchronous servo channels in tape drives

Cherubini

Jelitto

2011

Microsyst Technol

View full text Add to dashboard Cite

On tape media, longitudinal position (LPOS) information is normally encoded in dedicated servo bands to allow rapid and accurate positioning of the tape medium and correct data placement on the tape, which is typically several hundred meters long. Robust detection of the longitudinal position of the tape is important to guarantee reliable placement of data as well as rapid navigation to a target tape location. We introduce a method for improving the LPOS symbol detection reliability based on the weighted combining of soft information provided by two independent servo channels. The soft information for each servo channel is generated from metrics computed using a matched-filter detector for the two hypotheses corresponding to the binary LPOS symbols. The weights are derived from a signal-to-distortion ratio measure that is obtained at the output of each servo channel to optimally combine the available information from the two servo channels.

show abstract

Section: Introductionmentioning

confidence: 99%

LPOS symbol detection by soft-output combining of dual synchronous servo channels in tape drives

Cherubini

Jelitto

2011

Microsyst Technol

View full text Add to dashboard Cite

show abstract

“…Linear tape open (LTO) drives employ timing-based servo (TBS) (Barrett et al 1998) for track following, where the lateral position of a narrow servo reader is derived from the relative timing of pulses generated by reading prerecorded TBS patterns. The TBS format, which consists of magnetic transitions with two different slopes, enabled backward read/write compatibility and track-density increases over five LTO generations in the past decade (Standard ECMA-319 2001;Jaquette 2003).…”

Section: Introductionmentioning

confidence: 99%

Robust embedding of longitudinal position into tape servo signals

et al. 2011

View full text Add to dashboard Cite

In linear tape open technology, the longitudinal position (LPOS) on magnetic tape is embedded into the timing-based servo format by modulating the positions of magnetic transitions during the servo-writing process. An efficient method for embedding LPOS information into tape servo signals that is robust to LPOS detection errors is presented. The proposed concept is based on the serial concatenation of three data-processing stages: a lossless compression stage with a fixed compression ratio, an errorcorrection coding (ECC) stage and a runlength-limited coding stage. Various algorithms have been designed to compress and decompress the LPOS information. Errorcorrection codes, such as Hamming codes, Reed-Solomon codes and Golay codes, are used to protect LPOS and manufacturing information from detection errors. Finally, the random-error and the burst-error performance of various compression/ECC schemes are evaluated by computing the LPOS word error rate for servo signals corrupted by additive white Gaussian noise and by determining the burst-error correction capability of the proposed LPOS formats, respectively.

show abstract

“…A unique servo technology named Position Error Signal (PES) is designed for hard disk drive, 6,7 and another named Timed-Based Servo (TBS) is developed specifically for linear tape drives. 8,9 Following the magnetic coding in HDD, the ring's magnetic pattern is designed as shown in FIGURE 1(a) which consists of a sector ID and two rows of A and B burst patterns with overlapping zone for measurement synchronization. The patterns are created by perpendicularly magnetizing the magnetic medium in manufacturing.…”

Section: Operating Principlementioning

confidence: 99%