National Instruments PCI-4452 - Manual (Page 106)

Glossary
PCI-4451/4452 User Manual G-18 © National Instruments Corporation
trigger any event that causes or starts some form of data capture
TTL transistor-transistor logic
U
unipolar a signal range that is always positive (for example, 0 to +10 V)
update the output equivalent of a scan. One or more analog or digital output
samples. Typically, the number of output samples in an update is equal to
the number of channels in the output group. For example, one pulse from
the update clock produces one update which sends one new sample to every
analog output channel in the group.
UPDATE* update signal
update rate the number of output updates per second
V
V volts
V
DC
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
V
IL
volts, input low
V
in
volts in
V
OH
volts, output high
V
OL
volts, output low
V
ref
reference voltage
User.book Page 18 Tuesday, April 14, 1998 10:20 AM