Glossary
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National Instruments Corporation
G-9
S
s
Seconds.
S
Samples.
S/s
Samples per second—used to express the rate at which a digitizer or D/A
converter or DAQ device samples an analog signal.
scatter-gather
The term used to describe very high-speed DMA burst-mode transfers that
are made only by the bus master, and where noncontiguous blocks of
memory are transparently mapped by the controller to appear as a seamless
piece of memory.
SCXI
Signal Conditioning eXtensions for Instrumentation—the National
Instruments product line for conditioning low-level signals within an
external chassis near sensors so that only high-level signals are sent to DAQ
devices in the noisy PC environment. SCXI is an open standard available
for all vendors.
sensor
A device that responds to a physical stimulus (heat, light, sound, pressure,
motion, flow, and so on) and produces a corresponding electrical signal.
settling time
The amount of time required for a voltage to reach its final value within
specified limits.
signal conditioning
The manipulation of signals to prepare them for digitizing.
SOURCE
Source signal.
system noise
A measure of the amount of noise seen by an analog circuit or an ADC
when the analog inputs are grounded.
T
task
NI-DAQmx—a collection of one or more channels, timing, and triggering
and other properties that apply to the task itself. Conceptually, a task
represents a measurement or generation you want to perform.
terminal count
The highest value of a counter.
t
gh
Gate hold time.
t
gsu
Gate setup time.
