multifunction-rio-user-manual.pdf - 第64页
Glossary © National Instruments Corporation G-3 Mult ifunction Reconfigurable I/O User Manual CMOS Complementary metal-oxide semiconductor . CMRR Common-mode rejection ratio—A meas ure of an instrument’ s abilit y to rej…
Glossary
Multifunction Reconfigurable I/O User Manual G-2 © National Instruments Corporation
A
A Amperes.
A/D Analog-to-digital.
AC Alternating current.
ADC Analog-to-digital converter—An electronic device, often an integrated
circuit, that converts an analog voltage to a digital number.
AI Analog input.
AI<i> Analog input channel signal.
AIGND Analog input ground signal.
AISENSE Analog input sense signal.
AO Analog output.
AO<i> Analog output channel signal.
AOGND Analog output ground signal.
B
bipolar A signal range that includes both positive and negative values (for example,
–5 to +5 V).
C
CCelsius.
CalDAC Calibration DAC.
CH Channel—Pin or wire lead to which you apply or from which you read the
analog or digital signal. Analog signals can be single-ended or differential.
For digital signals, you group channels to form ports. Ports usually consist
of either four or eight digital channels.
cm Centimeter.
Glossary
© National Instruments Corporation G-3 Multifunction Reconfigurable I/O User Manual
CMOS Complementary metal-oxide semiconductor.
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
voltage
Any voltage present at the instrumentation amplifier inputs with respect to
amplifier ground.
CompactPCI Refers to the core specification defined by the PCI Industrial Computer
Manufacturer’s Group (PICMG).
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—A system that uses the computer to collect, receive,
and generate electrical signals.
dB Decibel—The unit for expressing a logarithmic measure of the ratio of
two signal levels: dB = 20log10 V1/V2, for signals in volts.
DC Direct current.
DGND Digital ground signal.
DIFF Differential mode.
DIO Digital input/output.
DIO<i> Digital input/output channel signal.
DMA Direct memory access—A method by which data can be transferred
to/from computer memory from/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.
DNL Differential nonlinearity—A measure in LSB of the worst-case deviation of
code widths from their ideal value of 1 LSB.
DO Digital output.
Glossary
Multifunction Reconfigurable I/O User Manual G-4 © National Instruments Corporation
E
EEPROM Electrically erasable programmable read-only memory—ROM that can be
erased with an electrical signal and reprogrammed.
F
FPGA Field-Programmable Gate Array.
FPGA VI A configuration that is downloaded to the FPGA and that determines the
functionality of the hardware.
G
glitch An unwanted signal excursion of short duration that is usually unavoidable.
H
hHour.
HIL Hardware-in-the-loop.
Hz Hertz.
I
I/O Input/output—The transfer of data to/from a computer system involving
communications channels, operator interface devices, and/or data
acquisition and control interfaces.
INL Relative accuracy.
L
LabVIEW Laboratory Virtual Instrument Engineering Workbench. LabVIEW is a
graphical programming language that uses icons instead of lines of text to
create programs.
LSB Least significant bit.