National Instruments Data Acquisition Device NI USB-621x User Manual
Page 169
Glossary
© National Instruments Corporation
G-11
mux
Multiplexer—A set of semiconductor or electromechanical switches
arranged to select one of many inputs to a single output. The majority of
DAQ cards have a multiplexer on the input, which permits the selection of
one of many channels at a time.
A switching device with multiple inputs that sequentially connects each of
its inputs to its output, typically at high speeds, in order to measure several
signals with a single analog input channel.
N
NI-DAQmx
The latest NI-DAQ driver with new VIs, functions, and development tools
for controlling measurement devices. The advantages of NI-DAQmx over
earlier versions of NI-DAQ include the DAQ Assistant for configuring
channels and measurement tasks for your device for use in LabVIEW,
LabWindows/CVI, and Measurement Studio; increased performance such
as faster single-point analog I/O; and a simpler API for creating DAQ
applications using fewer functions and VIs than earlier versions of
NI-DAQ.
NI-PGIA
.
non-referenced signal
sources
Signal sources with voltage signals that are not connected to an absolute
reference or system ground. Also called floating signal sources. Some
common example of non-referenced signal sources are batteries,
transformers, or thermocouples.
NRSE
Non-Referenced Single-Ended mode—All measurements are made with
respect to a common (NRSE) measurement system reference, but the
voltage at this reference can vary with respect to the measurement system
ground.
O
offset
The unwanted DC voltage due to amplifier offset voltages added to a signal.
P
period
The period of a signal, most often measured from one zero crossing to the
next zero crossing of the same slope. The period of a signal is the reciprocal
of its frequency (in Hz). Period is designated by the symbol T.