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Rockwell Automation 1761 MicroLogix 1000 Programmable Controllers User Manual

Page 400

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Preface

MicroLogix 1000 Programmable Controllers User Manual

G–2

control profile: The means by which a controller determines which outputs turn on
under what conditions.

counter: 1) An electro-mechanical relay-type device that counts the occurrence of
some event. May be pulses developed from operations such as switch closures,
interruptions of light beams, or other discrete events.
2) In controllers a software counter eliminates the need for hardware counters. The
software counter can be given a preset count value to count up or down whenever
the counted event occurs.

CPU (Central Processing Unit): The decision-making and data storage section of
a programmable controller.

data table: The part of the processor memory that contains I/O values and files
where data is monitored, manipulated, and changed for control purposes.

DIN rail: Manufactured according to Deutsche Industrie Normenausshus (DIN)
standards, a metal railing designed to ease installation and mounting of your
controller.

download: Data is transferred from a programming or storage device to another
device.

DTE (Data Terminal Equipment): Equipment that is attached to a network to
send or receive data, or both.

EMI: Electromagnetic interference.

encoder: 1) A rotary device that transmits position information. 2) A device that
transmits a fixed number of pulses for each revolution.

false: The status of an instruction that does not provide a continuous logical path on
a ladder rung.

FIFO (First-In–First-Out): The order that data is entered into and retrieved from
a file.

file: A collection of information organized into one group.

full-duplex: A bidirectional mode of communication where data may be
transmitted and received simultaneously (contrast with half-duplex).

half-duplex: A communication link in which data transmission is limited to one
direction at a time.

hard disk: A storage area in a personal computer that may be used to save
processor files and reports for future use.

high byte: Bits 8–15 of a word.