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Rockwell Automation 1766-Lxxxx MicroLogix 1400 Programmable Controllers User Manual User Manual

Page 393

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Rockwell Automation Publication 1766-UM001H-EN-P - May 2014

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Glossary

LIFO (Last-In-First-Out)

The order that data is entered into and retrieved from a file.

low byte

Bits 0 to 7 of a word.

logic

A process of solving complex problems through the repeated use of simple
functions that can be either true or false. General term for digital circuits and
programmed instructions to perform required decision making and
computational functions.

Master Control Relay (MCR)

A mandatory hard-wired relay that can be de-energized by any series-connected
emergency stop switch. Whenever the MCR is de-energized, its contacts open to
de-energize all application I/O devices.

mnemonic

A simple and easy to remember term that is used to represent a complex or
lengthy set of information.

modem

Modulator/demodulator. Equipment that connects data terminal equipment to a
communication line.

modes

Selected methods of operation. Example: run, test, or program.

negative logic

The use of binary logic in such a way that “0” represents the voltage level normally
associated with logic 1 (for example, 0 = +5V, 1 = 0V). Positive is more
conventional (for example, 1 = +5V, 0 = 0V).

network

A series of stations (nodes) connected by some type of communication medium.
A network may be made up of a single link or multiple links.

nominal input current

The current at nominal input voltage.

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