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Glossary
© National Instruments Corporation
G-11
Getting Started with Your PCI/PXI-6810 SDA
N
NCO
Numerically-Controlled Oscillator
NISDA
NI instrument driver for SDA cards
NIST
National Institute of Standards and Technology
nodes
execution elements of a block diagram consisting of functions,
structures, and subVIs
noise
an undesirable electrical signal—Noise comes from external sources
such as the AC power line, motors, generators, transformers,
fluorescent lights, soldering irons, CRT displays, computers, electrical
storms, welders, radio transmitters, and internal sources such as
semiconductors, resistors, and capacitors. Noise corrupts signals you
are trying to send or receive.
nonlatched digital I/O
a type of digital acquisition/generation where LabVIEW updates the
digital lines or port states immediately or returns the digital value of an
input line. Also called immediate digital I/O or non-handshaking.
nonreferenced signal
signal sources with voltage signals that are not connected to an absolute
sources
reference or system ground. Also called floating signal sources. Some
common example of nonreferenced signal sources are batteries,
transformers, or thermocouples.
O
onboard channels
channels provided by the plug-in DAQ board
onboard RAM
optional RAM usually installed into SIMM slots
operating system
base-level software that controls a computer, runs programs, interacts
with users, and communicates with installed hardware or peripheral
devices
optical coupler,
a device designed to transfer electrical signals by utilizing light waves
optocoupler
to provide coupling with electrical isolation between input and output.
Sometimes called optoisolator or photocoupler.
optical isolation
the technique of using an optoelectric transmitter and receiver to
transfer data without electrical continuity, to eliminate high-potential
differences and transients