Glossary
NI 6124/6154 User Manual G-4 ni.com
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.
DAQ See data acquisition (DAQ).
DAQ device A device that acquires or generates data and can contain multiple channels
and conversion devices. DAQ devices include plug-in devices, PCMCIA
cards, and DAQPad devices, which connect to a computer USB or 1394
(FireWire)® port. SCXI modules are considered DAQ devices.
DAQ-STC Data acquisition system timing controller—an application-specific
integrated circuit (ASIC) for the system timing requirements of a general
A/D and D/A system.
data acquisition
(DAQ)
1. Acquiring and measuring analog or digital electrical signals from
sensors, transducers, and test probes or fixtures.
2. Generating analog or digital electrical signals.
dB Decibel—the unit for expressing a logarithmic measure of the ratio of two
signal levels: dB = 20log10 V1/V2 for signals in volts.
dBc Decibel carrier—level difference referenced to a carrier level, c.
DC Direct current—although the term speaks of current, many different types
of DC measurements are made, including DC Voltage, DC current, and DC
power.
device 1. An instrument or controller you can access as a single entity that controls
or monitors real-world I/O points. A device often is connected to a host
computer through some type of communication network.
2. See DAQ device.
DI Digital input.
DIFF Differential mode—an analog input mode consisting of two terminals, both
of which are isolated from computer ground, whose difference is measured.
DIO Digital input/output.