Glossary
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National Instruments Corporation
G-13
PCI-4451/4452/4453/4454 User Manual
R
relative accuracy
a measure in LSB of the linearity of an ADC. It includes all non-linearity
and quantization errors. It does not include offset and gain errors of the
circuitry feeding the ADC.
resolution
the smallest signal increment that can be detected by a measurement
system. Resolution can be expressed in bits, in proportions, or in percent of
full scale. For example, a system has 12-bit resolution, one part in 4,096
resolution, and 0.0244% of full scale.
rise time
the difference in time between the 10% and 90% points of the step response
of a system
rms
root mean square—the square root of the average value of the square of the
instantaneous signal amplitude; a measure of signal amplitude
RSE
See SE.
RTSI bus
real-time system integration bus—the National Instruments timing bus that
connects DAQ devices directly, by means of connectors on top of the
boards, for precise synchronization of functions
S
s
seconds
S
samples
sample counter
the clock that counts the output of the channel clock, in other words, the
number of samples taken. On devices with simultaneous sampling, this
counter counts the output of the scan clock and hence the number of scans.
SE
single-ended—a term used to describe an analog input that is measured
with respect to a common ground
self-calibrating
a property of a DSA device that has an extremely stable onboard reference
and calibrates its own A/D and D/A circuits without manual adjustments by
the user
sensor
a device that responds to a physical stimulus (heat, light, sound, pressure,
motion, flow, and so on), and produces a corresponding electrical signal
signal conditioning
the manipulation of signals to prepare them for digitizing
