Industrial Automation Glossary – T, U, V, W, X, Y, Z
Written by Neal Babcock
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 often have a T
telnet
a standard method for logging into remote computers and having access if connect by a dumb terminal.
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.
through beam
a beam is projected over an opening. If the beam is broken the sensor is activated.
throughput
the speed that actual data is transmitted/processed, etc.
thumbwheel
a mechanical switch with multiple positions that allow digits to be entered directly.
timer
a device that can be set to have events happen at predetermined times.
titration
a procedure for determining the strength of a solution using a reagent for detection. A chemical is added at a slow rate until the reagent detects a change.
toggle switch
a switch with a large lever used for easy reviews of switch settings, and easy grasping.
token
an indicator of control. Often when a process receives a token it can operate, when it is done it gives it up.
top
down design
TOP (Technical Office Protocol)
a network protocol designed for offices. It was promoted in conjunction with MAP in the 1980s, but never became widely used.
topology
1. The layout of a network. 2. a mathematical topic describing the connection of geometric entities. This is used for B
toroidal core
a torus shaped magnetic core to increase magnetic conductivity.
torque
a moment or twisting action about an axis.
torus
a donut shape
TPDDI (Twisted Pair Distributed Data Interface)
counter rotating token ring network connected with twisted pair medium.
TQC (Total Quality Control)
a philosophical approach to developing quality methods that reach all levels and aspects of a company.
transceiver (transmitter receiver)
a device to electrically interface between the computer network card, and the physical network medium. Packet collision hardware is present in these devices.
transducer
a device that will convert energy from one form to another at proportional levels.
transformations
include translation, rotation, and scaling of objects mathematically using matrix algebra.
transformer
two separate coils wound about a common magnetic coil. Used for changing voltage, current and resistance levels.
transient
a system response that occurs because of a change. These effects dissipate quickly and we are left with a steady state response.
transmission path
a system component that is used for transmitting energy.
transport layer
an OSI network model layer.
TRIAC (TRIode Alternating Current)
a semiconductor switch suited to AC power.
truth table
an exhaustive list of all possible logical input states, and the logical results.
TTL (Transistor Transistor Logic)
a high speed for of transistor logic.
TTY
a teletype terminal.
turbine
a device that generates a rotational motion using gas or fluid pressure on fan blades or vanes.
turbulent flow
fluids moving past an object, or changing direction will start to flow unevenly. This will occur when the Reynold’s number exceeds 4000.
twisted pair
a scheme where wires are twisted to reduce the effects of EMI so that they may be used at higher frequencies. This is casually used to refer to 10b2 ethernet.
TXD (Transmitted Data)
an output line for serial data transmission. It will be connected to an RXD input on a receiving station.
UART
(Universal Asynchronous Receiver/Transmitter)
UDP (User Datagram Protocol)
a connectionless method for transmitting packets to other hosts on the network. It is seen as a counterpart to TCP.
ultrasonic
sound or vibration at a frequency above that of the ear (> 16KHz typ.) ultraviolet
UNIX
a very powerful operating system used on most high end and mid
UPS (Uninterruptable Power Supply)
a power supply that uses battery back up
user interfaces
the means of communicating with the computer.
VAC
a voltage that is AC.
vacuum
a pressure that is below another pressure.
valve
a system component for opening and closing mass/energy flow paths. An example is a water faucet or transistor.
vane
a blade that can be extended to provide a good mechanical contact and/or seal.
vapor
a gas.
variable
a changeable location in memory.
varistor
voltage applied changes resistance.
velocity
a rate of change or speed.
Venturi
an effect that uses an orifice in a flow to generate a differential pressure. These devices can generate small vacuums.
viscosity
when moved a fluid will have some resistance proportional to internal friction. This determines how fast a liquid will flow.
volatile memory
most memory will lose its contents when power is removed, making it volatile.
volt
a unit of electrical potential.
voltage rating
the range or a maximum/minimum limit that is required to prevent damage, and ensure normal operation.
volume
the size of a region of space or quantity of fluid.
vortex
a swirling pattern in fluid flow.
vortex shedding
a solid object in a flow stream might cause vortices. These vortices will travel with the flow and appear to be shed.
watchdog timer
a timer that expects to receive a pulse every fraction of a second. If a pulse is not received, it assumes the system is not operating normally, and a shutdown procedure is activated.
watt
a unit of power that is commonly used for electrical systems, but applies to all.
wavelength
the physical distance occupied by one cycle of a wave in a propagating medium.
word
1. a unit of 16 bits or two bytes. 2. a term used to describe a binary number in a computer (not limited to 16 bits).
work
the transfer of energy.
write
a digital value is stored in a memory location.
XFER
transfer.
XMIT
transmit.
