Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 507)

Glossary
G–3
inrush current: The temporary surge current produced when a device or
circuit is initially energized.
instruction: A mnemonic and data address defining an operation to be
performed by the controller. A rung in a program consists of a set of input
and output instructions. The input instructions are evaluated by the
controller as being true or false. In turn, the controller sets the output
instructions to true or false.
Instruction List program: A program written in a list format using
mnemonics. The program is used by a programmable controller to control
devices.
instruction set: The set of general purpose instructions available with a
given controller.
I/O (Inputs and Outputs): Consists of input and output devices that
provide and/or receive data from the controller.
jump: Change in normal sequence of program execution, by executing an
instruction that alters the program counter (sometimes called a branch). In
ladder programs a JUMP (JMP) instruction causes execution to jump to a
labeled rung.
ladder logic: A program written in a format resembling a ladder–like
diagram. The program is used by a programmable controller to control
devices.
LED (Light Emitting Diode): Used as status indicator for controller
functions and inputs and outputs.
LIFO (Last–In–First–Out): The order that data is entered into and
retrieved from a file.
low byte: Bits 0–7 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 hardwired 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.
modes: Selected methods of operation. Example: RRUN, RCSN, RSSN, or
RPRG.