National Instruments NI USB-621x User Manual
Page 167
Glossary
G-18
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Timebase
The reference signals for controlling the basic accuracy of time or
frequency-based measurements. For instruments, timebase refers to the
accuracy of the internal clock.
t
out
Output delay time.
Traditional NI-DAQ
(Legacy)
An upgrade to the earlier version of NI-DAQ. Traditional NI-DAQ (Legacy)
has the same VIs and functions and works the same way as
NI-DAQ 6.9.x. You can use both Traditional NI-DAQ (Legacy) and
NI-DAQmx on the same computer, which is not possible with NI-DAQ 6.9.x.
transducer
A device that responds to a physical stimulus (heat, light, sound, pressure,
motion, flow, and so on), and produces a corresponding electrical signal.
See also
trigger
1. Any event that causes or starts some form of data capture.
2. An external stimulus that initiates one or more instrument functions.
Trigger stimuli include a front panel button, an external input voltage
pulse, or a bus trigger command. The trigger may also be derived from
attributes of the actual signal to be acquired, such as the level and slope
of the signal.
t
sc
Source clock period.
t
sp
Source pulse width.
TTL
Transistor-Transistor Logic—A digital circuit composed of bipolar
transistors wired in a certain manner. A typical medium-speed digital
technology. Nominal TTL logic levels are 0 and 5 V.
U
USB
Universal Serial Bus—A 480 Mbit/s serial bus with up to 12-Mbps
bandwidth for connecting computers to keyboards, printers, and other
peripheral devices. USB 2.0 retains compatibility with the original USB
specification.
V
V
Volts.
V
cm
Common-mode voltage.