Table of Contents
Advertisement
E
EEPROM
EMC
encoder
EPROM
event
expansion ROM
external trigger
EXTSTROBE*
F
false triggering
FIFO
© National Instruments Corporation
electrically erasable programmable read-only memory—ROM that can be
erased with an electrical signal and reprogrammed
electromechanical compliance
a device that converts linear or rotary displacement into digital or pulse
signals. The most popular type of encoder is the optical encoder, which uses
a rotating disk with alternating opaque areas, a light source, and a
photodetector.
erasable programmable read-only memory—ROM that can be erased
(usually by ultraviolet light exposure) and reprogrammed
the condition or state of an analog or digital signal
an onboard EEPROM that may contain device-specific initialization and
system boot functionality
a voltage pulse from an external source that triggers an event such as A/D
conversion
external strobe signal
triggering that occurs at an unintended time
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-7
Glossary
PCI-4451/4452 User Manual
Advertisement
Table of Contents
