National Instruments Image Acquisition Software User Manual
Page 58
Glossary
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National Instruments Corporation
G-7
I
IC
integrated circuit
ID
identification
IEEE
Institute of Electrical and Electronics Engineers
in.
inches
INL
integral nonlinearity—A measure in LSB of the worst-case deviation from
the ideal A/D or D/A transfer characteristic of the analog I/O circuitry
instrument driver
a set of high-level software functions, such as NI-IMAQ, that controls
specific plug-in computer boards; instrument drivers are available in
several forms, ranging from a function callable from a programming
language to a virtual instrument (VI) in LabVIEW
interlaced
a video frame composed of two interleaved fields; the number of lines in a
field are half the number of lines in an interlaced frame
interpreter
a software utility that executes source code from a high-level language such
as Basic, C or Pascal, by reading one line at a time and executing the
specified operation. See also compiler.
interrupt
a computer signal indicating that the CPU should suspend its current task
to service a designated activity
interrupt level
the relative priority at which a device can interrupt
I/O
input/output—the transfer of data to/from a computer system involving
communications channels, operator interface devices, and/or data
acquisition and control interfaces
IRE
a relative unit of measure (named for the Institute of Radio Engineers).
0 IRE corresponds to the blanking level of a video signal, 100 IRE to the
white level. Note that for CIR/PAL video the black level is equal to the
blanking level or 0 IRE, while for RS-170/NTSC video the black level is
at 7.5 IRE.
IRQ
interrupt request
UM.book Page 7 Monday, July 13, 1998 9:49 AM