Dell PowerVault TL2000 Dell Model TL2000/TL4000 Tape Library- User's Guide - Page 270

bus. A facility for transferring data between several devices located between two end points, only one device being able to transmit at a given moment. byte. A string consisting of a certain number of bits (usually 8) that are treated as a unit and represent a character. A fundamental data unit. C capacity. The amount of data that can be contained on storage media and expressed in bytes of data. cartridge storage slot. Individual slot located within a magazine that is used to house tape cartridges. caution (notice). A word to call attention to possible personal harm to people. Contrast with attention and danger. centimeter (cm). One one-hundredth of a meter (0.01 m). Approximately 0.39 inch. channel command. An instruction that directs a data channel, control unit, or device to perform an operation or set of operations. char. Character. CHK. Check. cleaning cartridge. A tape cartridge that is used to clean the heads of a tape drive. Contrast with data cartridge. command. A control signal that initiates an action or the start of a sequence of actions. compact disc (CD). A disc, usually 4.75 inches in diameter, from which data is read optically by means of a laser. CU. Control unit. D danger (notice). A word to call attention to possible lethal harm to people. Contrast with attention and caution. data. Any representations such as characters or analog quantities to which meaning is or might be assigned. data buffer. The storage buffer in the control unit. This buffer is used to increase the data transfer rate between the control unit and the channel. data cartridge. A tape cartridge dedicated to storing data. Contrast with cleaning cartridge. data check. A synchronous or asynchronous indication of a condition caused by invalid data or incorrect positioning of data. dc. Direct current. DCS. Designated Cleaning Slot degauss. To make a magnetic tape nonmagnetic by means of electrical coils carrying currents that neutralize the magnetism of the tape. degausser. A device that makes magnetic tape nonmagnetic. degradation. A decrease in quality of output or throughput or an increase in machine error rate. degraded. Decreased in quality of output or throughput or increased machine error rate. deserialize. To change from serial-by-bit to parallel-by-byte. compression. The process of eliminating gaps, empty fields, redundancies, and unnecessary data to shorten the length of records or blocks. concurrent. Refers to diagnostic procedures that can be run on one control unit while the rest of the subsystem remains available for customer applications. contingent connection. A connection between a channel path and a drive caused when a unit check occurs during an I/O operation. controller. A device that provides the interface between a system and one or more tape drives. control path drive. A drive that communicates messages from the host computer to the library in which the drive is installed. CP. Circuit protector. detented. A part being held in position with a catch or lever. device. Any hardware component or peripheral, such as a tape drive or tape library, that can receive and send data. device driver. A file that contains the code needed to use an attached device. DIAG . Diagnostic section of maintenance information manual. differential. See High Voltage Differential (HVD). direct access storage. A storage device in which the access time is independent of the location of the data. download. (1) To transfer programs or data from a computer to a connected device, typically a personal ctrl. Control. I-2 Dell PowerVault TL2000 Tape Library and TL4000 Tape Library User's Guide