Glossary
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National Instruments Corporation
G-5
PCI-MIO E Series User Manual
F
FIFO
first-in first-out memory buffer—FIFOs are often used on DAQ
devices to temporarily store incoming or outgoing data until that
data can be read or written. For example, an analog input FIFO
stores the results of A/D conversions until the data can be read into
system memory. Programming the DMA controller and servicing
interrupts 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 in the FIFO ahead of time. This again reduces the
effect of latencies associated with getting the data from system
memory to the DAQ device.
FREQ_OUT
frequency output signal
ft
feet
G
GATE
gate signal
GPCTR
general purpose counter
GPCTR0_GATE
general purpose counter 0 gate signal
GPCTR1_GATE
general purpose counter 1 gate signal
GPCTR0_OUT
general purpose counter 0 output signal
GPCTR1_OUT
general purpose counter 1 output signal
GPCTR0_SOURCE
general purpose counter 0 clock source signal
GPCTR1_SOURCE
general purpose counter 1 clock source signal
GPCTR0_UP_DOWN
general purpose counter 0 up down
GPCTR1_UP_DOWN
general purpose counter 1 up down
