National Instruments PCI-4451 用户手册
Glossary
PCI-4451/4452 User Manual
G-14
©
National Instruments Corporation
peak to peak
a measure of signal amplitude; the difference between the highest and
lowest excursions of the signal
lowest excursions of the signal
PFI
programmable function input
Plug and Play devices
devices that do not require DIP switches or jumpers to configure resources
on the devices—also called switchless devices
on the devices—also called switchless devices
port
(1) a communications connection on a computer or a remote controller
(2) a digital port, consisting of four or eight lines of digital input and/or
output
(2) a digital port, consisting of four or eight lines of digital input and/or
output
posttriggering
the technique used on a DAQ board to acquire a programmed number of
samples after trigger conditions are met
samples after trigger conditions are met
potentiometer
an electrical device the resistance of which can be manually adjusted; used
for manual adjustment of electrical circuits and as a transducer for linear or
rotary position
for manual adjustment of electrical circuits and as a transducer for linear or
rotary position
ppm
parts per million
pretriggering
the technique used on a DAQ board to keep a continuous buffer filled with
data, so that when the trigger conditions are met, the sample includes the
data leading up to the trigger condition
data, so that when the trigger conditions are met, the sample includes the
data leading up to the trigger condition
propagation
the transmission of a signal through a computer system
propagation delay
the amount of time required for a signal to pass through a circuit
pts
points
pulse trains
multiple pulses
pulsed output
a form of counter signal generation by which a pulse is outputted when a
counter reaches a certain value
counter reaches a certain value
Q
quantization error
the inherent uncertainty in digitizing an analog value due to the finite
resolution of the conversion process
resolution of the conversion process
quantizer
a device that maps a variable from a continuous distribution to a discrete
distribution
distribution
User.book Page 14 Tuesday, April 14, 1998 10:20 AM