| 摘要 |
Servo elements contained within a tape head detect a lateral displacement the magnetic tape relative to the tape head and generate position error signals corresponding to such lateral displacement. To aid in servo monitoring, the position error signals are sampled at predetermined times and the samples output or stored in machine-readable form. Each sample is classified as bad if it exceeds a predetermined threshold. Samples are analyzed to determine, for each time a bad position error signal occurs, how many successive position error signals are also bad. Samples are also analyzed to determine the relationship between bad position error signals samples and total samples. This data may be used for a number of different purposes. For example, this information may be used to identify differences between performance on top and bottom servo edges, or problems with the servo writing mechanism. Performance variations among different servo elements may also be identified. Such data may also be used to help recognize large "dropouts" or "fades" in the tape media. Furthermore, the data may also be analyzed to yield an overall indication of the media surface and edge quality of the media. Importantly, this information may be employed to pinpoint servo read errors, distinguishing between media problems and servo element malfunctions. Data obtained in accordance with the invention may also be used to evaluate tape media, with one possible implementation applying a numerical rank to factory-new tape media and subsequently binning the media according to their numerical ranks.
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