Glossary
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National Instruments Corporation
G-9
DAQArb 5411 User Manual
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PA<0..15>
digital pattern generator outputs
passband
the range of frequencies which a device can properly propagate or
measure
pattern generation
a type of handshaked (latched) digital I/O in which internal counters
generate the handshaked signal, which in turn initiates a digital transfer.
Because counters output digital pulses at a constant rate, this means you
can generate and retrieve patterns at a constant rate because the
handshaked signal is produced at a constant rate.
PCI
Peripheral Component Interconnect—a high-performance expansion
bus architecture originally developed by Intel to replace ISA and EISA.
It is achieving widespread acceptance as a standard for PCs and work-
stations; it offers a theoretical maximum transfer rate of 132 Mbytes/s.
PCLK
digital pattern clock output
peak to peak
a measure of signal amplitude; the difference between the highest and
lowest excursions of the signal
pipeline
a high-performance processor structure in which the completion of an
instruction is broken into its elements so that several elements can be
processed simultaneously from different instructions
PLL
phase-locked loop—a circuit that synthesizes a signal whose frequency
is exactly proportional to the frequency of a reference signal
PLL Ref
a PLL input that accepts an external reference clock signal and phase
locks to it the DAQArb 5411 internal clock
Plug and Play devices
devices that do not require dip switches or jumpers to configure
resources on the devices—also called switchless devices
Plug and Play ISA
a specification prepared by Microsoft, Intel, and other PC-related
companies that will result in PCs with plug-in boards that can be fully
configured in software, without jumpers or switches on the boards
ppm
parts per million
pre-attenuation offset
an offset provided to the signal before it reaches the attenuators
