Final Flashcards
What type of sensor is an RTD?
Thermo- Resistor
What does a thermistor require to generate a mili amp signal?
A power source
In an RTD its resistance does what as the ambient temperature does what?
The resistance goes up as the ambient temperature goes up
What can a thermistor be used to measure what in a circuit?
Current
Does a thermo couple clearly have a positive temperature?
No
What type of temperature coefficient does a thermistor have?
A negative temperature coefficient
What will two dissimilar metals wires twisted together and dipped in cold water will produce what?
A small amount of voltage
True or false? A bimetallic strip will turn a system on and off but will not indicate the approximate ambient temperature of a room
True
Is the thermocouple the most expensive and complex temperature sensor?
No
What does a combustion furnace use as fuel to create heat?
Fossil fuel
An electric arc furnace uses carbon probes to supply electricity into a crucible to melt what?
Metal
A resistance furnace uses electricity to allow coils to heat. This application is commonly used for what?
Forced air furnace
What are the two sides of the refrigeration cycle have for pressure?
High and Low pressure
What happens in the evaporator side of the refrigeration cycle?
It is where heat is being absorbed
True or false? The condenser in the refrigeration cycle is the hot side of cycle. This can be where heat is gained to the system
False
What moves the refrigerant through the system?
The compressor
What does the law of thermodynamics tell us?
Heat is gained or lost
What is the only point at which molecular movement exists known as?
Absolute zero
What is the purpose of the refrigeration cycle?
Absorb heat
What are the two most common types of temperature measurements?
Farienhiet and celcius
What is the method of heat exchange that occurs through a liquid or gas?
Convection
What is happening to heat in the evaporator side of the refrigeration cycle?
It is being absorbed
What side of the cycle is the condenser in the refrigeration cycle?
High pressure
What can the HMI also be known as?
The operator interface
What can the HMI take the place of?
Physically wired discrete inputs such as a push button
What can be sent from the PLC to the HMI?
An analog input
Can the HMI receive discrete or analog inputs and outputs from the PLC?
Yes
How does the HMI communicate?
Ethernet
Using a system that can accept an operator interface could allow for control of the system from where?
More than one location
What can be viewed from the HMI screen?
Graphs, Trends, and Alarms
Monitoring a set point can be done from the HMI, what can this help the operator do?
Tune a loop
Do the panel view and the PLC run on the same exact program and application?
No
True or False? When tuning a loop the objective is to deviate from the set point as often as possible?
False
True or False? In Reference to a control loop, over shooting is known to be a good thing. At the same undershooting is okay as well?
False
What does it mean if a control loop is hunting?
It is not properly tuned or consistently meeting set point
What is swan diving?
When an actuator controlling a process continually goes fully on and then fully off
What type of input are the solenoid valves from the HMI to the PLC?
Discrete
What do the letters P, I, D stand for?
Proportional Intergral and deritive
What is an example of an analog output to the HMI screen?
The current speed at which the motor is running in HZ
What does GRT, LES, EQU, DIV all represent in Rslogix?
Function Blocks
What is point to point level control?
It will have two set points, one to turn the system on and one to turn the system off
What is continuous level control?
It will always monitor one setpoint and try to maintain that set point
What is level defined as according to a manufacturing process?
The height at which a container is filled with a material
What is open loop control?
Cheaper to install
Usually no feedback signal
Typically requires an operator
Usually not automatic
What is closed loop control?
Will have feedback signal
Can be automatic
Has measurement devices or sensors
Can run 24/7
Has a PLC or some type of controller
What is process control?
The set point remain unchanged
Objective of the system is to maintain set-point at all times
Example is batch process- making cookies
What is motion control?
Also referred to as servo control
Uses PID block
setpoint changes frequently
A cookie baking manufacturing process is known to be what type of process manufacturing?
Batch
A water treatment plant is considered what type of process manufacturing?
A continuos
What is the type of sensor/ measurement device used in lab to sense the level of water in the tank?
DP level transmitter
What should one considered when selecting a measurement device?
What is the material being measured?
What is the cost of the sensor?
How accurate does it have to be?
What is a mechanical measurement device?
A paddle wheel or other types of displacement methods
What are electronic or indirect measurement devices?
Conductive probes
Radar level detector
D.P Cell
All sensors with a transmitter or transducer
What are power sources in level control?
A pump or auger to move material
Static pressure tank
What are transfer systems in level control?
Pipes and conveyors
When building the on off level controller in lab using the push button program what function block needs to be copy and pasted in from the HMI program?
DIV
What is the process variable?
The main point of the system that the set point is trying to maintain
What is a measurement device?
It is known as the EYE of the system, it provides a feedback signal of the controlled variable
What is a set point?
Is the designated input value applied to the control loop
What is an actuator?
It is what alters energy into a mechacnial motion
What is a error detector?
Compares the set point to the feedback signal and produces an output
What is the manufacturing process?
The operation of actuators and a control system to maintain a controlled variable at its desired set point
What is something that negatively affects a manufacturing process?
Disturbance
If a pump is moving water through the lab station, what can it be considered?
The muscle and actuator
What does IP stand for?
Internent Protocol
What IP version do we use in the lab?
IPV4
What usually holds all the components of the PLC?
The rack
What allows all of the components to be powered up?
The back plain
How do the input, output and CPU all share information?
The back plain
Where is the ladder diagram file stored in the PLC?
The CPU
