Table of Contents
Advertisement
Glossary
fiber-optic cable A jacketed cable of thin strands
of glass that carries pulses of light that transmit
data for high-speed transmissions over medium to
long distances. The cable can be single mode,
which carries a single signal from a laser or light-
emitting diode light source, or multimode, which
carries multiple signals from either light source.
fiber optics The branch of optical technology
concerned with the transmission of radiant power
through fibers made of transparent materials such
as glass, fused silica, and plastic. (E)
Fibre Channel (FC) The standard from the
National Committee for Information Technology
Standards that defines an ultra high-speed,
content-independent, multilevel data transmission
interface that supports multiple protocols
simultaneously. Fibre Channel supports
connectivity to millions of devices over copper
and/or fiber-optic physical media and provides the
best characteristics of both networks and channels
over diverse topologies.
field replaceable unit (FRU) An assembly that
is replaced in its entirety when any one of its
components fails. (IBM)
file-protect To prevent the destruction or
overwriting of data stored on cartridge tape. See
also write-protect.
firmware An ordered set of instructions and data
stored in a way that is functionally independent of
main storage; for example, microprograms stored
in a ROM. (T) Also known as "microcode."
FSC See fault symptom code.
G
g gram.
Gateway A 32-bit, or 4-byte number, in dotted
decimal format (typically written as four numbers
separated by periods, such as 107.4.1.3 or
84.2.1.111) that is applied to an IP Address to
identify router interface.
GB See gigabyte.
Glossary-4
get An activity in which a robotic hand obtains a
cartridge from a cell or drive.
gigabyte (GB) One billion (10
referring to memory capacity, 1,073,741,824 in
decimal notation. (IBM)
H
HBA See host bus adapter.
hand assembly A part of the library robot whose
function is to grasp cartridges and move them
between storage cells and drives. A camera on the
hand assembly reads cartridge volume labels.
Hertz (Hz) A unit of frequency equal to one
cycle per second. For example, in the United
States, power line frequency is 60 Hz, or a change
in voltage polarity 120 times per second.
high voltage differential (HVD) A type of
SCSI interface. The HVD interface allows longer
cable lengths of up to 25 m (82 ft), but throughput
is slower in data transfer rates than LVD (low
voltage differential).
host The primary computer on a network, with
which other computers interact.
host bus adapter (HBA) A circuit installed in a
multi-platform host or device that interfaces
between the device and the bus.
host controlling software The logical interface
between the host operating system and the library
components.
hot swapping A method of component
replacement in which the system containing the
component remains online during removal of the
failed component and insertion of a replacement.
Hz See Hertz.
I
in. See inch.
inch A unit of measure equal to 25.4 mm.
Seventh Edition
9
) bytes. When
MT9104
Advertisement
Table of Contents
