National Instruments Network Device DAQ S User Manual
Page 163
Glossary
G-10
ni.com
t
gw
Gate pulse width.
THD
Total harmonic distortion—the ratio of the total rms signal due to harmonic
distortion to the overall rms signal, in dB or percent.
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.
thermocouple
A temperature sensor created by joining two dissimilar metals. The
junction produces a small voltage as a function of the temperature.
t
off
An offset (delayed) pulse; the offset is t nanoseconds from the falling edge
of the AI CONV CLK* signal.
t
out
Output delay time.
t
p
Period of a pulse train.
transducer
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.
V
V
Volts.
V
CC
Nominal +5 V power supply provided by the PC motherboard.
V
cm
Common-mode noise and ground potential.
VDC
Volts direct current.
VI, virtual instrument
1. A combination of hardware and/or software elements, typically used
with a PC, that has the functionality of a classic stand-alone instrument.
2. A LabVIEW software module (VI), which consists of a front panel user
interface and a block diagram program.
V
IH
Volts, input high.