Glossary
LabWindows/CVI Standard Libraries G-6 © National Instruments Corporation
pretriggering The technique used on a DAQ board to keep a continuous buffer filled with
data, so that when the trigger conditions are met, the sample includes the
data leading up to the trigger condition.
pts Points.
R
resolution The smallest signal increment that can be detected by a measurement
system. Resolution can be expressed in bits, in proportions, or in percent of
full scale. For example, a system has 12-bit resolution, one part in
4,096 resolution, and 0.0244 percent of full scale.
RTD Resistance temperature detector. A metallic probe that measures
temperature based upon its coefficient of resistivity.
S
s Seconds.
S/s Samples per second; used to express the rate at which a DAQ board
samples an analog signal.
Sample-and-Hold
(S/H) A circuit that acquires and stores an analog voltage on a capacitor for a
short period of time.
SCXI Signal Conditioning eXtensions for Instrumentation; the National
Instruments product line for conditioning low-level signals within an
external chassis near sensors so only high-level signals are sent to DAQ
boards in the noisy PC environment.
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.
Single-Ended (SE)
Inputs An analog input that is measured with respect to a common ground.
software trigger A programmed event that triggers an event such as data acquisition.
standard libraries The LabWindows/CVI Analysis, ANSI C, DDE, Formatting and I/O, GPIB
and GPIB-488.2, RS-232, TCP, and Utility libraries.
STC System Timing Controller.
synchronous (1) Hardware—Property of an event that is synchronized to a reference cloc
k
(2) Software—Property of a function that begins an operation and returns
only when the operation is complete.