Allen-Bradley micrologix 1500, User Manual

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Publication 1764-UM001A-US-P
Glossary 7
56
An EIA standard that specifies electrical, mechanical, and functional characteristics
for serial binary communication circuits.
UXQ PRGH
An executing mode during which the controller scans or executes the logic
program.
UXQJ
A rung contains input and output instructions. During Run mode, the inputs on a
rung are evaluated to be true or false. If a path of true logic exists, the outputs are
made true (energized). If all paths are false, the outputs are made false
(de-energized).
578
Remote Terminal Unit
VDYH
To save a program to a computer hard disk.
VFDQ
The scan is made up of four elements: input scan, program scan, output scan, and
housekeeping.
VFDQ WLPH
The time required for the controller to complete one scan.
VLQNLQJ
A term used to describe current flow between two devices. A sinking device
provides a direct path to ground.
VRXUFLQJ
A term used to describe current flow between two devices. A sourcing device or
circuit provides a power.
VWDWXV
The condition of a circuit or system.
WHUPLQDO
A point on an I/O module that external devices, such as a push button or pilot
light, are wired to.
WKURXJKSXW
The time between when an input turns on and a corresponding output turns on or
off. Throughput consists of input delays, program scan, output delays, and
overhead.
WUXH
The status of an instruction that provides a continuous logical path on a ladder
rung. AB Spares