Glossary – Rockwell Automation 1756-HSC ControlLogix High Speed Counter Module User Manual
Page 115
Publication 1756-UM007C-EN-P - November 2011
Glossary
accumulated value (ACC) The number of elapsed time intervals or counted events.
actuator 1) A device that converts an electrical signal into mechanical motion. 2) In a
general sense, any machine/process load device (for example, transducer) of a
controller output circuit. See output device (
).
address 1) A character string that uniquely identifies a memory location. 2) A character
string that uniquely identifies the physical location of an input or output
circuit.
algorithm A set of procedures used for solving a problem in a finite number of steps.
American wire gauge (AWG) A standard system used for designating the size of electrical conductors.
Gauge numbers have an inverse relationship to size; larger numbers have a
smaller cross-sectional area. However, a single-strand conductor has a larger
cross-sectional area than a multi-strand conductor of the same gauge so that
they have the same current-carrying specification.
analog circuit 1) A circuit in which the signal can vary continuously between specified limits.
2) A circuit that provides a continuous function. 3) Contrasted with digital
circuit (
page 117
).
asynchronous 1) Lacking a regular time relationship; not related through repeating time
patterns. 2) Contrasted with synchronous (
page 121
).
AWG See American wire gauge (
backplane A printed-circuit board, at the back of a chassis, that provides electrical
interconnection between the modules inserted into the chassis.
balanced circuit 1) A circuit whose two sides are electrically alike and symmetrical to a common
reference point, usually ground. 2) Contrasted with unbalanced circuit
(
).
bandwidth The range of frequencies over which a system is designed to operate. The
bandwidth is expressed in Hertz between the highest and lowest frequencies.
baseband link 1) A communication link with only one channel, encoded by on/off switching.
Examples: DH and DH+ links. 2) Contrasted with carrier-band link
(
) and broadband link (
).
bidirectional I/O module An I/O module whose communication with the scanner or processor is
bidirectional and therefore uses both input and output image areas.
broadband link 1) A communication link that can have multiple channels. Each channel signal
modulates its own carrier frequency. Example: LAN/1 link. 2) Contrasted with
carrier-band link (
).