beautypg.com

National Instruments AT-MIO-16X User Manual

Page 305

background image

Glossary

AT-MIO-16X User Manual

G-22

© National Instruments Corporation

SE

single-ended—a term used to describe an analog input that is measured
with respect to a common ground

self-calibrating

a property of a DAQ board that has an extremely stable onboard
reference and calibrates its own A/D and D/A circuits without manual
adjustments by the user

sensor

a device that responds to a physical stimulus (heat, light, sound,
pressure, motion, flow, and so on), and produces a corresponding
electrical signal

settling time

the amount of time required for a voltage to reach its final value within
specified limits

S/H

sample-and-hold—a circuit that acquires and stores an analog voltage
on a capacitor for a short period of time

shared memory

See dual-access memory

signal conditioning

the manipulation of signals to prepare them for digitizing

signal divider

performing frequency division on an external signal

SIMM

single in-line memory module

SMB

a type of miniature coaxial signal connector

SNR

signal-to-noise ratio—the ratio of the overall rms signal level to the rms
noise level, expressed in dB

software trigger

a programmed event that triggers an event such as data acquisition

software triggering

a method of triggering in which you simulate an analog trigger using
software. Also called conditional retrieval.

source impedance

a parameter of signal sources that reflects current-driving ability of
voltage sources (lower is better) and the voltage-driving ability of
current sources (higher is better)

SOURCE input pin

an counter input pin where the counter counts the signal transitions

SPDT

single-pole double throw—a property of a switch in which one terminal
can be connected to one of two other terminals

SS

simultaneous sampling—a property of a system in which each input or
output channel is digitized or updated at the same instant