Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 506)

Glossary
G–2
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 controller 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.
DOS: Disk Operating System. The operating system used to operate a
personal computer.
DTE (Data Terminal Equipment): Equipment that is attached to a network
to send or receive data, or both.
edit: To create or modify a ladder or instruction list program.
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.
floppy disk: A thin flexible disk, coated with magnetic oxide and used to
store data.
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.
HHP (Hand–Held Programmer): A device used to monitor and develop
control logic programs for the micro controller.
high byte: Bits 8–15 of a word.
input device: A device, such as a push button or a switch, that supplies
signals through input circuits to the controller.