National Instruments NI USB-621x - Manual (Page 167)

Glossary
NI USB-621x User Manual G-18 ni.com
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
sensor .
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.