Glossary
G-4
www.ni.com
D
D/A
Digital-to-analog.
DAC
Digital-to-analog converter. An electronic device, often an integrated
circuit, that converts a digital number into a corresponding analog voltage
or current.
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
DLL
Dynamic link library. A software module in Microsoft Windows
containing executable code and data that can be called or used by
Windows applications or other DLLs; functions and data in a DLL are
loaded and linked at run time when they are referenced by a Windows
application or other DLLs.
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.
driver
Software that controls a specific hardware device, such as an image
acquisition board.
