Automating Manufacturing Systems - Process Control and ...

plc glossary - 35.2
annealing - heating of metal to relieve internal stresses. In many cases this may soften the material.
annotation - a special note added to a design for explanatory purposes.
ANSI (American National Standards Institute) - a developer of standards, and a member of ISO.
APF (All Plastic Fibre cable) - fiber optic cable that is made of plastic, instead of glass.
API (Application Program Interface) - a set of functions, and procedures that describes how a program will
use another service/library/program/etc.
APT (Automatically Programmed Tools) - a language used for directing computer controlled machine tools.
application - the task which a tool is put to, This normally suggets some level of user or real world
interaction.
application layer - the top layer in the OSI model that includes programs the user would run, such as a mail
reader.
arc - when the electric field strength exceeds the dielectric breakdown voltage, electrons will flow.
architecture - they general layout or design at a higher level.
armature - the central rotating portion of a DC motor or generator, or a moving part of a relay.
ARPA (Advanced Research Projects Agency) - now DARPA. Originally funded ARPANET.
ARPANET - originally sponsored by ARPA. A packet switching network that was in service from the early
1970s, until 1990.
ASCII (American Standard Code for Information Interchange) - a set of numerical codes that correspond to
numbers, letters, special characters, and control codes. The most popular standard
ASIC (Application Specific Integrated Circuit) - a specially designed and programmed logic circuit. Used
for medium to low level production of complex functions.
aspirator - a device that moves materials with suction.
assembler - converts assembly language into machine code.
assembly language - a mnemonic set of commands that can be directly converted into commands for a CPU.
associative dimensioning - a method for linking dimension elements to elements in a drawing.
associative laws - Boolean algebra laws A+(B+C) = (A+B)+C or A(BC) = (AB)C
asynchronous - events that happen on an irregular basis, and are not predictable.
asynchronous communications (serial) - strings of characters (often ASCII) are broken down into a series of
on/off bits. These are framed with start/stop bits, and parity checks for error detection, and then
send out one character at a time. The use of start bits allows the characters to be sent out at
irregular times.
attenuation - to decrease the magnitude of a signal.
attenuation - as the sound/vibration energy propagates, it will undergo losses. The losses are known as
attenuation, and are often measured in dB. For general specifications, the attenuation may be tied
to units of dB/ft.
attribute - a nongraphical feature of a part, such as color.
audible range - the range of frequencies that the human ear can normally detect from 16 to 20,000 Hz.
automatic control - a feedback of a system state is compared to a desired value and the control value for the
system is adjusted by electronics, mechanics and/or computer to compensate for differences.
automated - a process that operates without human intervention.
auxiliary power - secondary power supplies for remote or isolated systems.
AWG (American Wire Gauge) - specifies conductor size. As the number gets larger, the conductors get
smaller.
35.2 B
B-spline - a fitted curve/surface that is commonly used in CAD and graphic systems.
backbone - a central network line that ties together distributed networks.
background - in multitasking systems, processes may be running in the background while the user is
working in the foreground, giving the user the impression that they are the only user of the
machine (except when the background job is computationally intensive).