Glossary
6023E/6024E/6025E User Manual G-4 ni.com
DAQ data acquisition—(1) collecting and measuring electrical signals from
sensors, transducers, and test probes or fixtures and processing the
measurement data using a computer; (2) collectingand measuring the same
kinds of electrical signals with A/D and/or DIO boards plugged into a
computer, and possibly generating control signals with D/A and/or DIO
boards in the same computer
dB decibel—the unit for expressing a logarithmic measure of the ratio of two
signal levels: dB=20log10 V1/V2, for signals in volts
DC direct current
DGND digital ground signal
DIFF differential input configuration
differential amplifier an amplifier with two input terminals, neither of which are tied to a ground
reference, whose voltage difference is amplified
differential input the two-terminal input to a differential amplifier
DIO digital input/output
dithering the addition of Gaussian noise to an analog input signal
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 LSB of the worst-case deviation of
code widths from their ideal value of 1 LSB
DO digital output
drivers/driver software software that controls a specific hardware device such as a DAQ device
E
EEPROM electrically erasable programmable read-only memory—ROM that can be
erased with an electrical signal and reprogrammed. Some SCXI modules
contain an EEPROM to store measurement-correction coefficients.