Glossary
DIO 6533 User Manual G-10
©
National Instruments Corporation
TTL transistor-transistor logic
U
unstrobed digital I/O a type of digital input or output in which software reads or writes the
digital line or port states directly, without using any handshaking or
hardware-controlled timing functions. Also called immediate,
nonhandshaking, or unlatched digital I/O.
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.
V
V volts
Vcc the voltage of the power supply from the computer, approxi matel y 5 V
VDC volts direct current
VIH volts, input high
VIL volts, input low
Vin volts in
VOH volts, output high
VOL volts, output low
Vref reference voltage
W
wire data path between nodes
wired-OR a type of output driver that provides sink current but little or no source
current, and is typically used with a pull-up resistor to provide source
current. If you connect two or more wired-OR outputs together, any one