Glossary
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National Instruments Corporation
G-3
Compact PCI
Refers to the core specification defined by the PCI Industrial Computer
Manufacturer’s Group (PICMG).
conversion device
Device that transforms a signal from one form to another. For example,
analog-to-digital converters (ADCs) for analog input and digital-to-analog
converters (DACs) for analog output.
CPU
Central processing unit.
D
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 or DIO boards plugged into a computer,
and possibly generating control signals with D/A and/or DIO boards in
the same computer.
dB
Decibel. The unit for expressing a logarithmic measure of the ratio of two
signal levels: dB = 20log
10
V1/V2, for signals in volts.
DC
Direct current.
default setting
A default parameter value recorded in the driver; in many cases, the default
input of a control is a certain value (often 0) that means
use the current
default setting.
DIN
Deutsche Industrie Norme. A format for electrical connectors.
DMA
Direct memory access. A method by which data can be transferred to and
from computer memory from and 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.
DRAM
Dynamic RAM.
drivers
Software that controls a specific hardware device, such as an image
acquisition board.
dynamic range
The ratio of the largest signal level a circuit can handle to the smallest
signal level it can handle (usually taken to be the noise level), normally
expressed in decibels.
