National Instruments PCI-4451 Switch User Manual


 
Glossary
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National Instruments Corporation G-5 PCI-4451/4452 User Manual
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 board to dissipate current for analog or digital output
signals
current sourcing the ability of a DAQ board 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
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=20log
10
(V
1
/V
2
), for signals in volts
DC direct current
DC coupled allowing the transmission of both AC and DC signals
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.
User.book Page 5 Tuesday, April 14, 1998 10:20 AM