National Instruments NI USB-621x - Manual (Page 162)

Glossary
© National Instruments Corporation G-13 NI USB-621x User Manual
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.
PCI Express A high-performance expansion bus architecture originally developed by
Intel to replace PCI. PCI Express offers a theoretical maximum transfer rate
that is dependent upon lane width. A ×1 link theoretically provides
250 MB/s in each direction—to and from the device. Once overhead is
accounted for, a ×1 link can provide approximately 200 MB/s of input
capability and 200 MB/s of output capability. Increasing the number of
lanes in a link increases maximum throughput by approximately the same
factor.
PCIe See PCI Express.
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 .