National Instruments Isolated Analog Input Device NI PXI-4224 - Manual (Page 73)

Glossary
© National Instruments Corporation G-3 NI PXI-4224 User Manual
CMR Common-mode rejection.
CMRR Common-mode rejection ratio—A measure of an instrument’s ability to
reject interference from a common-mode signal, usually expressed in
decibels (dB).
common-mode signal Any voltage present at the instrumentation amplifier inputs with respect to
amplifier ground.
counter/timer A circuit that counts external pulses or clock pulses (timing).
D
D/A Digital-to-analog.
D GND Digital ground signal.
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 and/or DIO devices plugged into a computer,
and possibly generating control signals with D/A and/or DIO devices in the
same computer.
DAQ Assistant A configuration assistant with which you define and configure your DAQ
operation.
DAQ-STC Data acquisition system timing controller chip.
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.
differential input An analog input consisting of two terminals, both of which are isolated
from computer ground, the difference of which is measured.
DIO Digital input/output.
dithering The addition of Gaussian noise to an analog input signal.