Glossary
PCI-4451/4452/4453/4454 User Manual
G-4
www.ni.com
conversion device
device that transforms a signal from one form to another. For example,
analog-to-digital converters (ADCs) for analog input, digital-to-analog
converters (DACs) for analog output, digital input or output ports, and
counter/timers are conversion devices.
conversion time
the time required, in an analog input or output system, from the moment a
channel is interrogated (such as with a read instruction) to the moment that
accurate data is available
CONVERT*
convert signal
counter/timer
a circuit that counts external pulses or clock pulses (timing)
coupling
the manner in which a signal is connected from one location to another
crosstalk
an unwanted signal on one channel due to an input on a different channel
current drive
capability
the amount of current a digital or analog output channel is capable of
sourcing or sinking while still operating within voltage range specifications
current sinking
the ability of a DAQ device to dissipate current for analog or digital output
signals
current sourcing
the ability of a DAQ device to supply current for analog or digital output
signals
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
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 devices plugged into a computer,
and possibly generating control signals with D/A and/or DIO devices in the
same computer
dB
decibel—the unit for expressing a logarithmic measure of the ratio of two
signal levels: dB = 20log
10
(V
1
/V
2
), for signals in volts
