National Instruments USB-621 Series, User Manual

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Glossary
NI USB-621x User Manual G-14 ni.com
single-ended o u tp u t A circ u it whose o u tp u t signal is present between one o u tp u t terminal and
gro u nd.
software triggering A method of triggering in which yo u sim u late an analog trigger u sing
software. Also called conditional retrieval .
so u rce impedance A parameter of signal so u rces that reflects c u rrent-driving ability of voltage
so u rces (lower is better) and the voltage-driving ability of c u rrent so u rces
(higher is better).
synchrono u s 1. Hardware—A property of an event that is synchronized to a reference
clock.
2. Software—A property of a f u nction that begins an operation and
ret u rns only when the operation is complete. A synchrono u s process is,
therefore, locked and no other processes can r u n d u ring this time.
T
task In NI-DAQmx, a collection of one or more channels, timing, and triggering
and other properties that apply to the task itself. Concept
u ally, a task
represents a meas u rement or generation yo u want to perform.
TC See terminal co u nt.
terminal An object or region on a node thro u gh which data passes.
terminal co u nt The highest val u e of a co u nter.
t
gh
Gate hold time.
t
gs u
Gate set u p time.
t
gw
Gate p u lse width.
Timebase The reference signals for controlling the basic acc u racy of time or
freq u ency-based meas u rements. For instr u ments, timebase refers to the
acc u racy of the internal clock.
t
o u t
O u tp u t delay time.
transd u cer A device that responds to a physical stim u l u s (heat, light, so u nd, press u re,
motion, flow, and so on), and prod u ces a corresponding electrical signal.
See also sensor .