National Instruments IMAQ PCI-1428, Руководство пользователя

Страница: 42 / 51

Glossary
© National Instruments Corporation G-3 IMAQ PCI-1428 User Manual
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.
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.
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.
E
EEPROM Electrically erasable programmable read-only memory. ROM that can be
erased with an electrical signal and reprogrammed.
external trigger A voltage pulse from an external source that triggers an event such as
A/D conversion.