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Glossary
©
National Instruments Corporation
G-13
PCI/PXI-1408 and NI-IMAQ for Win95/NT
TRIG
trigger signal
trigger
any event that causes or starts some form of data capture
trigger control and
circuitry that routes, monitors, and drives the external and
mapping circuitry
RTSI bus trigger lines; you can configure each of these lines to
start or stop acquisition on a rising or falling edge.
TTL
transistor-transistor logic
U
UV plane
See YUV.
V
V
volts
VCO
voltage-controlled oscillator—an oscillator that changes
frequency depending on a control signal; used in a PLL to
generate a stable pixel clock
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
video line
a video line consists of a HSYNC, back porch, active pixel region,
and a front porch
VSYNC
vertical sync signal—the synchronization pulse generated at the
beginning of each video field that tells the video monitor when to
start a new field
VSYNCIN
vertical sync in signal
W
white reference level
the level that defines what is white for a particular video system
See also black reference level.