Glossary
G-6
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National Instruments Corporation
N
noise
An undesirable electrical signal—noise comes from external sources such
as the AC power line, motors, generators, transformers, fluorescent lights,
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.
NRSE
Nonreferenced single-ended mode—all measurements are made with
respect to a common (NRSE) measurement system reference, but the
voltage at this reference can vary with respect to the measurement system
ground.
O
OUT
Output pin—a counter output pin where the counter can generate various
TTL pulse waveforms.
P
PCI
Peripheral Component Interconnect—a high-performance expansion bus
architecture originally developed by Intel to replace ISA and EISA. It is
achieving widespread acceptance as a standard for PCs and work-stations;
it offers a theoretical maximum transfer rate of 132 MB/s.
port
(1) A communications connection on a computer or a remote controller.
(2) A digital port, consisting of four or eight lines of digital input and/or
output.
ppm
Parts per million.
pu
Pull-up.
PWM
Pulse-width modulation.
PXI
Stands for PCI eXtensions for Instrumentation. PXI is an open specification
that builds off the CompactPCI specification by adding
instrumentation-specific features.
