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Glossary
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Getting Started with Your PCI/PXI-6810 SDA
FIFO
first-in first-out memory buffer—the first data stored is the first data
sent to the acceptor. FIFOs are often used on DAQ devices to
temporarily store incoming or outgoing data until that data can be
retrieved or output. For example, an analog input FIFO stores the results
of A/D conversions until the data can be retrieved into system memory,
a process that requires the servicing of interrupts and often the
programming of the DMA controller. This process can take several
milliseconds in some cases. During this time, data accumulates in the
FIFO for future retrieval. With a larger FIFO, longer latencies can be
tolerated. In the case of analog output, a FIFO permits faster update
rates, because the waveform data can be stored on the FIFO ahead of
time. This again reduces the effect of latencies associated with getting
the data from system memory to the DAQ device.
filtering
a type of signal conditioning that allows you to filter unwanted signals
from the signal you are trying to measure
flyby
a type of high-performance data transfer in which the data bytes pass
directly from the source to the target without being transferred to the
controller
FPGA
Field Programmable Gate Array
ft
feet
G
gain
the factor by which a signal is amplified, sometimes expressed in
decibels
GPIB
General Purpose Interface bus, synonymous with HP-IB. The standard
bus used for controlling electronic instruments with a computer. Also
called IEEE 488 bus because it is defined by ANSI/IEEE Standards
488-1978, 488.1-1987, and 488.2-1987.
H
h
hour
handle
pointer to a pointer to a block of memory; handles reference arrays and
strings. An array of strings is a handle to a block of memory containing
handles to strings.