National Instruments PCI-4451 用户手册
Glossary
PCI-4451/4452 User Manual
G-10
©
National Instruments Corporation
input impedance
the measured resistance and capacitance between the input terminals of a
circuit
circuit
input offset current
the difference in the input bias currents of the two inputs of an
instrumentation amplifier
instrumentation amplifier
instrument driver
a set of high-level software functions that controls a specific GPIB, VXI,
or RS-232 programmable instrument or a specific plug-in DAQ board.
Instrument drivers are available in several forms, ranging from a function
callable language to a virtual instrument (VI) in LabVIEW.
or RS-232 programmable instrument or a specific plug-in DAQ board.
Instrument drivers are available in several forms, ranging from a function
callable language to a virtual instrument (VI) in LabVIEW.
instrumentation
amplifier
amplifier
a circuit whose output voltage with respect to ground is proportional to the
difference between the voltages at its two inputs
difference between the voltages at its two inputs
integrating ADC
an ADC whose output code represents the average value of the input
voltage over a given time interval
voltage over a given time interval
interrupt
a computer signal indicating that the CPU should suspend its current task
to service a designated activity
to service a designated activity
interrupt level
the relative priority at which a device can interrupt
I/O
input/output—the transfer of data to/from a computer system involving
communications channels, operator interface devices, and/or data
acquisition and control interfaces
communications channels, operator interface devices, and/or data
acquisition and control interfaces
I
OH
current, output high
I
OL
current, output low
IRQ
interrupt request
isolation
a type of signal conditioning in which you isolate the transducer signals
from the computer for safety purposes. This protects you and your
computer from large voltage spikes and makes sure the measurements from
the DAQ device are not affected by differences in ground potentials.
from the computer for safety purposes. This protects you and your
computer from large voltage spikes and makes sure the measurements from
the DAQ device are not affected by differences in ground potentials.
isolation voltage
the voltage that an isolated circuit can normally withstand, usually
specified from input to input and/or from any input to the amplifier output,
or to the computer bus
specified from input to input and/or from any input to the amplifier output,
or to the computer bus
User.book Page 10 Tuesday, April 14, 1998 10:20 AM