National Instruments AT-MIO-16X - Manual (Page 289)

Glossary
AT-MIO-16X User Manual G-6 © National Instruments Corporation
D
D/A digital-to-analog.
DAC digital-to-analog converter—an electronic device, often an integrated
circuit, that converts a digital number into a corresponding analog
voltage or current
daisy-chain a method of propagating signals along a bus, in which the devices are
prioritized on the basis of their position on the bus
DAQ data acquisition—(1) collecting and measuring electrical signals from
sensors, transducers, and test probes or fixtures and inputting them to a
computer for processing; (2) collecting and 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
DC coupled allowing the transmission of both AC and DC signals
DCS distributed control system—a large-scale process control system
characterized by a distributed network of processors and I/O
subsystems that encompass control, user interfacing, data collection,
and system management. DCSs are commonly used in large industrial
facilities, such as a petroleum refinery or paper mill.
default setting a default parameter value recorded in the driver. In many cases, the
default input of a control is a certain value (often 0) that means use the
current default setting. For example, the default input for a parameter
may be do not change current setting, and the default setting may be no
AMUX-64T boards. If you do change the value of such a parameter, the
new value becomes the new setting. You can set default settings for
some parameters in the configuration utility or manually using switches
located on the device.
delta-sigma a high-accuracy circuit that samples at a higher rate and lower
modulating ADC resolution than is needed and (by means of feedback loops) pushes
the quantization noise above the frequency range of interest. This
out-of-band noise is typically removed by digital filters.