National Instruments Signal Processing Engineering Educational Device NI SPEEDY-33 User Manual
Page 36
Glossary
G-4
ni.com
D
D/A
Digital-to-Analog
DAQ
data acquisition—(1) Collecting and measuring electrical signals from
sensors, transducers, and test probes or fixtures and processing the
measurement data using a computer.
(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.
DAQ device
A data acquisition device. Examples are DIO, E Series MIO, and Lab/1200
plug-in data acquisition devices.
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
DC coupled
Allowing the transmission of both AC and DC signals.
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.
device
A plug-in data acquisition product, card, or pad that can contain multiple
channels and conversion devices. Plug-in products, PCMCIA 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.
digital
An electronic technology where a signal only has two states: off and on,
most often called zero and one. In contrast, analog refers to a signal that can
have a continuous range of values.
digital I/O
The capability of an instrument to generate and acquire digital signals.
Static digital I/O refers to signals where the values are set and held, or
rarely change. Dynamic digital I/O refers to digital systems where the
signals are continuously changing, often at multi-MHz clock rates. The
NI SPEEDY-33 is a static digital I/O device.
digital port
.