Glossary
NI5102 User Manual G-8 ni.com
expansionROM an onboard EEPROMthat may contain device-specific initialization and
system boot functionality
externaltrigger avoltage pulse from an external source that triggers an event such as
A/D conversion
F
falsetriggering triggering that occurs at an unintended time
FET field-effecttransistor
fetch-and-deposit adata transfer in which the data bytes are transferred from the source to the
controller,and then from the controller to the target
FIFO first-infirst-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 retrievedo r output. For
example,an analog in put FIFO stores the results of A/D conversionsuntil
the data can be retrievedinto system memory, a process that requires the
servicing of interrupts and often the programming of the DMA controller.
Thisprocess 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
permitsfaster update rates, because the waveform data can be stored on the
FIFOahead of time.This again reducesthe effect of latencies associated
withgetting the data from system memory to the DAQ device
filtering atype of signal conditioning that allows you to filter unwanted signals from
the signal you aret rying to measure
flash ADC an ADC whose output code is determined in a single step by a bank of
comparators and encoding logic
floating signalsources signalsources with voltage signals that are not connected to an absolute
reference or system ground. Also called nonreferenced signal sources.
Some common exampleof floating signal sources are batteries,
transformers,or t hermocouples
ft feet