National Instruments NI USB-621x 158

		Glossary
function	1.	A built-in execution element, comparable to an operator, function, or
		statement in a conventional language.
	2.	A set of software instructions executed by a single line of code that may
		have input and/or output parameters and returns a value when executed.
G
glitch	An unwanted signal excursion of short duration that is usually unavoidable.
GND	See ground.
ground	1.	A pin.
	2.	An electrically neutral wire that has the same potential as the
		surrounding earth. Normally, a noncurrent-carrying circuit intended for
		safety.
	3.	A common reference point for an electrical system.
H
hardware	The physical components of a computer system, such as the circuit boards,
	plug-in devices, chassis, enclosures, peripherals, and cables.
hardware triggering	A form of triggering where you set the start time of an acquisition and
	gather data at a known position in time relative to a trigger signal.
Hz	1.	Hertz—The SI unit for measurement of frequency. One hertz (Hz)
		equals one cycle per second.
	2.	The number of scans read or updates written per second.
hysteresis	Lag between making a change and the effect of the change.
I
I/O	Input/Output—The transfer of data to/from a computer system involving
	communications channels, operator interface devices, and/or data
	acquisition and control interfaces.

G-9