Glossary
G-6
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National Instruments Corporation
R
referenced signal
sources
signal sources with voltage signals that are referenced to a system ground,
such as the earth or a building ground. Also called grounded signal sources.
relative accuracy
a measure in LSB of the accuracy 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 resolution.
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
referenced single-ended mode—all measurements are made with respect
to a common reference measurement system or a ground. Also called a
grounded measurement system.
RSVD
reserved bit, pin, or signal
RTD
resistance temperature detector—a metallic probe that measures
temperature based on its coefficient of resistivity
S
s
seconds
scan
one or more analog samples taken at the same time, or nearly the same time.
Typically, the number of input samples in a scan is equal to the number of
channels in the input group. For example, one scan, acquires one new
sample from every analog input channel in the group.
scan clock
the clock controlling the time interval between scans. On devices with
interval scanning support (for example, the AT-MIO-16F-5), this clock
gates the channel clock on and off. On devices with simultaneous sampling
(for example, the EISA-A2000), this clock clocks the track-and-hold
circuitry.
scan rate
the number of scans a system takes during a given time period, usually
expressed in scans per second
SCANCLK
scan clock signal used to increment to the next channel after each E Series
DAQ device analog-to-digital conversion
