National Instruments PCI-4452 User Manual
Page 105
Glossary
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National Instruments Corporation
G-17
PCI-4451/4452 User Manual
STC
system timing controller
switchless device
devices that do not require dip switches or jumpers to configure resources
on the devices—also called Plug and Play devices
synchronous
(1) hardware—a property of an event that is synchronized to a reference
clock (2) software—a property of a function that begins an operation and
returns only when the operation is complete
system noise
a measure of the amount of noise seen by an analog circuit or an ADC when
the analog inputs are grounded
system RAM
RAM installed on a personal computer and used by the operating system,
as contrasted with onboard RAM
T
TC
terminal count—the highest value of a counter
T/H
track-and-hold—a circuit that tracks an analog voltage and holds the value
on command
THD
total harmonic distortion—the ratio of the total rms signal due to harmonic
distortion to the overall rms signal, in decibel or a percentage
THD+N
signal-to-THD plus noise—the ratio in decibels of the overall rms signal to
the rms signal of harmonic distortion plus noise introduced
throughput rate
the data, measured in bytes/s, for a given continuous operation, calculated
to include software overhead.
transducer
See sensor
transducer excitation
a type of signal conditioning that uses external voltages and currents to
excite the circuitry of a signal conditioning system into measuring physical
phenomena
transfer rate
the rate, measured in bytes/s, at which data is moved from source to
destination after software initialization and set up operations; the maximum
rate at which the hardware can operate
TRIG1 (EXT_TRIG)
trigger 1 signal
TRIG2 (PRETRIG)
trigger 2 signal
User.book Page 17 Tuesday, April 14, 1998 10:20 AM