Glossary
G-4
www.ni.com
F
F
farads
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.
FSR
full-scale range
G
G
gain
gain error
the difference between the actual and intended gain of a system
H
hex
hexadecimal
Hz
hertz—the number of scans read or updates written per second
I
in.
inches
indirect scanning
the measurement that occurs when a signal passes on the SCXIbus from the
scanned SCXI module to the cabled SCXI module
input damage level
the highest voltage level that you can apply to the module without
damaging it
