Glossary
©
National Instruments Corporation
G-3
SCXI-1102/B/C User Manual
D
D/A
digital-to-analog
DAQ
data acquisition—(1) collecting and measuring electrical signals from
sensors, transducers, and test probes or fixtures and inputting them to a
computer for processing; (2) collecting and measuring the same kinds
of electrical signals with A/D and/or DIO boards plugged into a
computer, and possibly generating control signals with D/A and/or DIO
boards in the same computer
DAQD*/A
data acquisition digital to analog signal
dB
decibel—the unit for expressing a logarithmic measure of the ratio of
two signal levels: dB=20log10 V1/V2, for signals in volts
DC
direct current
device
a plug-in data acquisition board, card, or pad that can contain multiple
channels and conversion devices. Plug-in boards, PC cards, and devices
such as the DAQPad-1200, which connects to your computer parallel
port, are all examples of DAQ devices. SCXI modules are distinct from
devices, with the exception of the SCXI-1200, which is a hybrid.
DGND
digital ground signal
DIFF
differential configuration
differential input
an analog input consisting of two terminals, both of which are isolated
from computer ground, whose difference is measured
DIN
Deutsche Industrie Norme
DMA
direct memory access—a method by which data can be transferred to/
from computer memory from/to a device or memory on the bus while
the processor does something else. DMA is the fastest method of
transferring data to/from computer memory.
DMM
digital millimeter
DNL
differential nonlinearity—a measure in LSB of the worst-case deviation
of code widths from their ideal value of 1 LSB
