Automating Manufacturing Systems - Process Control and ...

plc glossary - 35.27
steady state - describes a system response after a long period of time. In other words the transient effects
have had time to dissipate.
STEP (Standard for the Exchange of Product model data) - a standard that will allow transfer of solid model
data (as well as others) between dissimilar CAD systems.
step response - a typical test of system behavior that uses a sudden step input change with a measured
response.
stoichiometry - the general field that deals with balancing chemical equations.
strain gauge - a wire mounted on a surface that will be stretched as the surface is strained. As the wire is
stretched, the cross section is reduced, and the proportional change in resistance can be measured
to estimate strain.
strut - a two force structural member.
subroutine - a reusable segment of a program that is called repeatedly.
substrate - the base piece of a semiconductor that the layers are added to.
switching - refers to devices that are purely on or off. Clearly this calls for discrete state devices.
synchronous - two or more events happen at predictable times.
synchronous motor - an AC motor. These motors tend to keep a near constant speed regardless of load.
syntax error - an error that is fundamentally wrong in a language.
synthesis - is the specification of values for the design variables. The engineer synthesizes a design and then
evaluates its performance using analysis.
system - a complex collection of components that performs a set of functions.
35.20 T
T1 - a 1.54 Mbps network data link.
T3 - a 45 Mbps network data link. This can be done with parallel T1 lines and packet switching.
tap - a connection to a power line.
tare - the ratio between unloaded and loaded weights.
TCP (Transmission Control Protocol) - a transport layer protocol that ensures reliable data communication
when using IP communications. The protocol is connection oriented, with full duplex streams.
tee - a tap into a larger line that does not add any special compensation, or conditioning. These connectors
ofen have a T-shape.
telnet - a standard method for logging into remote computers and having access if connect by a dumb
terminal.
temperature - the heat stored in an object. The relationship between temperature and energy content is
specific to a material and is called the specific heat.
temperature dependence - as temperature varies, so do physical properties of materials. This makes many
devices sensitive to temperatures.
thermal conductivity - the ability of a material to transfer heat energy.
thermal gradient - the change in temperature as we move through a material.
thermal lag - a delay between the time heat energy is applied and the time it arrives at the load.
thermistor - a resistance based temperature measurement device.
thermocouple - a device using joined metals that will generate a junction potential at different temperatures,
used for temperature measurement.
thermopiles - a series of thermocouples in series.
thermoresistors - a category including RTDs and thermistors.
throughput - the speed that actual data is transmitted/processed, etc.
through beam - a beam is projected over an opening. If the beam is broken the sensor is activated.
thumbwheel - a mechanical switch with multiple positions that allow digits to be entered directly.
TIFF (Tagged Image File Format) - an image format best suited to scanned pictures, such as Fax
transmissions.
time-division multiplex - a circuit is switched between different devices for communication.
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