User manual

Glossary
NI-DAQ User Manual for PC Compatibles G-6 ni.com
F
FIFO A 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.
G
gain the factor by which a signal is amplified, sometimes expressed in decibels
group a collection of digital ports, combined to form a larger entity for digital
input and/or output
GPS Global Positioning System. A satellite-based system created and
maintained by the U.S. Department of Defense that allows its users
to determine their position, velocity, and time.
GPS receiver An instrument that receives signals from GPS satellites
GUI graphical user interface
H
Hz hertz
I
I/O input/output
ID identification
IDE Integrated Development Environment