Automating Manufacturing Systems - Process Control and ...

plc glossary - 35.7
noise immunity.
CNC (Computer Numerical Control) - machine tools are equipped with a control computer, and will perform
a task. The most popular is milling.
coalescing - a process for filtering liquids suspended in air. The liquid condenses on glass fibers.
coaxial cable - a central wire contains a signal conductor, and an outer shield provides noise immunity. This
configuration is limited by its coaxial geometry, but it provides very high noise immunity.
coax - see coaxial cable.
cogging - a machine steps through motions in a jerking manner. The result may be low frequency vibration.
coil - wire wound into a coil (tightly packed helix) used to create electromagnetic attraction. Used in relays,
motors, solenoids, etc. These are also used alone as inductors.
collisions - when more than one network client tries to send a packet at any one time, they will collide. Both
of the packets will be corrupted, and as a result special algorithms and hardware are used to abort
the write, wait for a random time, and retry the transmission. Collisions are a good measure of
network overuse.
colorimetry - a method for identifying chemicals using their colors.
combustion - a burning process generating heat and light when certain chemicals are added.
command - a computer term for a function that has an immediate effect, such as listing the files in a
directory.
communication - the transfer of data between computing systems.
commutative laws - Booleans algebra laws A+B = B+A and AB=BA.
compare - a computer program element that examines one or more variables, determines equality/inequality,
and then performs some action, sometimes a branch.
compatibility - a measure of the similarity of a design to a standard. This is often expressed as a percentage
for software. Anything less than 100% is not desirable.
compiler - a tool to change a high level language such as C into assembler.
compliment - to take the logical negative. TRUE becomes false and vice versa.
component - an interchangeable part of a larger system. Components can be used to cut down manufacturing
and maintenance difficulties.
compressor - a device that will decrease the volume of a gas - and increase the pressure.
computer - a device constructed about a central instruction processor. In general the computer can be
reconfigured (software/firmware/hardware) to perform alternate tasks.
Computer Graphics - is the use of the computer to draw pictures using an input device to specify geometry
and other attributes and an output device to display a picture. It allows engineers to communicate
with the computer through geometry.
concentric - a shared center between two or more objects.
concurrent - two or more activities occur at the same time, but are not necessarily the same.
concurrent engineering - all phases of the products life are considered during design, and not later during
design review stages.
condenser - a system component that will convert steam to water. Typically used in power generators.
conduction - the transfer of energy through some medium.
configuration - a numbers of multifunction components can be connected in a variety of configurations.
connection - a network term for communication that involves first establishing a connection, second data
transmission, and third closing the connection. Connectionless networking does not require
connection.
constant - a number with a value that should not vary.
constraints - are performance variables with limits. Constraints are used to specify when a design is feasible.
If constraints are not met, the design is not feasible.
contact - 1. metal pieces that when touched will allow current to pass, when separated will stop the flow of
current. 2. in PLCs contacts are two vertical lines that represent an input, or internal memory
location.
contactor - a high current relay.
continuous Noise - a noise that is ongoing, and present. This differentiates from instantaneous, or
intermittent noise sources.
continuous Spectrum - a noise has a set of components that are evenly distributed on a spectral graph.