Glossary
PCI-4451/4452/4453/4454 User Manual
G-6
www.ni.com
DIO
digital input/output
DMA
direct memory access—a method by which data can be transferred to/from
computer memory from/to a device or memory on the bus while the
processor does something else. DMA is the fastest method of transferring
data to/from computer memory.
DNL
differential nonlinearity—a measure in LSBs of the worst-case deviation of
code widths from their ideal value of 1 LSB
down counter
performing frequency division on an internal signal
drivers
software that controls a specific hardware device such as a DAQ device or
a GPIB interface device
DSA
dynamic signal acquisition
dynamic range
the ratio of the largest signal level a circuit can handle to the smallest signal
level it can handle (usually taken to be the noise level), normally expressed
in decibels
E
EEPROM
electrically erasable programmable read-only memory—ROM that can be
erased with an electrical signal and reprogrammed
event
the condition or state of an analog or digital signal
external trigger
a voltage pulse from an external source that triggers an event such as A/D
conversion
EXTSTROBE*
external strobe signal
F
false triggering
triggering that occurs at an unintended time
