Rockwell Automation 1747-PTxx Getting Started Guide for HHT - Manual (Page 68)

A–B
Glossary
Getting Started Guide
for HHT
G–1
Glossary
The following terms are used throughout this manual. Refer to them while
working in this manual.
address: A character string that uniquely identifies a memory location. For
example, I:1/0 is the memory address for the data located in the Input file
location 1/0.
APS: (Advanced Programming Software) Software for a computer used to
monitor and develop SLC 500 ladder logic programs.
attach: To establish communication with a processor.
bit: The smallest storage location in memory that contains either a 1 (ON) or
a 0 (OFF).
branch: A parallel logic path within a rung of a ladder program.
communication scan: A part of the SLC’s operating cycle. Communication
with other devices, such as the HHT, takes place.
controller: A device, such as a programmable controller, used to monitor
input devices and control output devices.
CMOS (Complementary Metal–Oxide Semiconductor): A semiconductor
device in which an electric field controls the conductance of a channel under
a metal electrode called a gate.
CPU (Central Processing Unit): The decision–making and data storage
section of a programmable controller.
data file: An area within a processor file that contains the status of inputs,
outputs, the processor, timers, counters, and so on.
download: To transfer a program from HHT memory to an SLC.
edit: To create or modify a ladder program.
expansion rack: A 2–slot rack used only with fixed controllers.
false: The status of an instruction that does not provide a continuous logical
path on a ladder rung.
file: A collection of information organized into one group.
fixed controller: A controller with a power supply, CPU, and I/O integrated
into a single package.
function keys: Keys on a personal computer or HHT keyboard labeled F1,
F2 and so on. The operation of each of these keys is defined by HHT.
hardware: The components that comprise a programmable controller, such
as Input modules, Output modules, and the CPU.
HHT: Hand–held Terminal.
I/O (Inputs and Outputs): Consists of input and output devices which
provide and/or receive data from the programmable controller.