Glossary
© National Instruments Corporation G-13 NI 6238/6239 User Manual
NI-PGIA See instrumentation amplifier.
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
PCI Peripheral Component Interconnect—A high-performance expansion bus
architecture originally developed by Intel to replace ISA and EISA. It offers
a theoretical maximum transfer rate of 132 MB/s.
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.
periods The number of periods of a signal.
PFI Programmable Function Interface.
PGIA Programmable Gain Instrumentation Amplifier.
physical channel See channel.
Plug and Play devices Devices that do not require DIP switches or jumpers to configure resources
on the devices. Also called switchless devices port.
1. A communications connection on a computer or a remote controller;
2. A digital port, consisting of four or eight lines of digital input and/or
output.
posttriggering The technique used on a DAQ device to acquire a programmed number of
samples after trigger conditions are met.