Glossary
©
National Instruments Corporation G-7 NI-IMAQ User Manual
IIC 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 blankin g 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
at7.5 IRE.
IRQ interrupt request
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