Appendix
D
D-1
Glossary
To help build a common understanding of processor terminology, this
glossary lists those terms and abbreviations used in this manual to describe
and identify various Allen-Bradley processor system components and
functions.
Each term in this glossary is concisely defined. These definitions provide
a basis for understanding Allen-Bradley processors. In cases where a term
may have more than one meaning, we give only those definitions directly
related to our products.
When reading this glossary, you will notice that common electrical terms
and symbols are not defined. We assume you have a working knowledge
of basic electricity.
AC Input Module
An I/O module that converts various ac signals originating at user devices
to the appropriate logic level signal for use within the processor.
AC Output Module
An I/O module that converts the logic level signal of the processor to a
usable output signal to control a user ac device.
Accumulated Value
The number of elapsed timed intervals or counted events.
Address
(1) An alphanumeric value that uniquely identifies where data is stored.
(2) An alphanumeric value used to identify a specific I/O rack, module
group, and terminal.
Ambient Temperature
The temperature of the air surrounding a module or system.
Analog
An expression of values which can vary continuously between
specified limits.
Analog Input Module
A module that converts an analog input signal to a number that can be
manipulated by the processor.
Introduction
A
