Glossary
G-4
©
National Instruments Corporation
device
(1) A plug-in data acquisition board, card, or pad that can contain multiple
channels and conversion devices. Plug-in boards, PCMCIA cards, and
devices such as the DAQPad-1200, which connects to your computer
parallel port, are all examples of DAQ devices. (2) A component of a
VXIbus system, normally one VXIbus board. However, multiple-slot
devices and multiple-device modules can operate on a VXIbus system as a
single device. Some examples of devices are computers, multimeters,
multiplexers, oscillators, operator interfaces, and counters.
digital input group
A collection of digital input ports. You can associate each group with its
own clock rates, handshaking modes, buffer configurations, and so on. A
port cannot belong to more than one group.
digital output group
A collection of digital output ports. You can associate each group with its
own clock rates, handshaking modes, buffer configurations, and so on. A
port cannot belong to more than one group.
digital trigger
A TTL-level signal having two discrete levels—high and low.
DIN
Deutsche Industrie Norme
DIO
digital input/output
DIP
dual inline package
dithering
The addition of Gaussian noise to an analog input signal.
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 by 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
DRAM
Dynamic RAM
drivers/driver software
Software that controls a specific hardware device such as a DAQ board.
dual-access memory
Memory that can be sequentially, but not simultaneously, accessed by more
than one controller or processor. Also known as shared memory.
dual-ported memory
Memory that can be simultaneously accessed by more than one controller
or processor.