Industrial Controls and PLCs D2L Flashcards
What devices make decisions based on the machine conditions?
Logic devices
True or False;
Switches are an example of a discreet signalling device.
True
discreet output - either on or off
What device is used to provide actuation of a temperature switch?
Bi-metallic Strip
What type of device is used to prevent an action from occurring if another action is already taking place, where damage could occur if both actions were to happen at once?
Interlock Switch
Select the output device from the list below.
A) Pilot light
B) Photocell
C) Temperature sensor
D) Limit switch
Pilot light
True or False;
A relay uses high voltage to switch a low voltage circuit on or off.
False
What causes an electrical relay to activate or change states?
Magnetism in the coil
How is a latching relay signalled to unlatch?
When power is sent to the unlatching coil
True or False;
Relay logic is also known as hardwired logic because the logic is determined by the wire connections.
True
Which type of logic system generally can be modified more quickly?
-Relay logic
-Programmable Logic Control(PLC)
Programmable Logic Control (PLC)
What component of a PLC analyzes the inputs to determine the output requirements?
Processor
What component of a PLC system is used to protect the processor and modules from low voltage conditions?
Transient Surpressing Transformer
When would an input with the instruction XIC become true?
—] [—
When the input became closed
XIC - examine if closed
If a PLC had a problem with an output module, how would the PLC indicate the problem to the person troubleshooting the problem?
flashing I/O status light
A pressure switch asks, Is the pressure 100 psi? What is the answer?
Yes or No
Different types of pressure switches;
Compressed air pressure
Low air pressure
Steam pressure
Water pressure
Hydraulic pressure
What are proximity switches used for?
Proximity switches are used for non-contact detection of non-metallic and metallic objects.
What is meant by number of poles?
Number of poles describe how many separate circuits are controlled by a switch.
What are throws?
Throws are the number of positions a switch can adopt.
.
/o___________ Cr1-1
/
______o/………o_________Cr1-2
What is this?
a shit drawing of Single Pole Double throw relay.
Solid State relays have;
-No moving parts(no possibility or arcing)
-Less chance of failure
-Can be used for high amps
-Also known as transistors or semi-conductors
-No mechanical linkage (as with relays)
The “AND” function is series or parallel?
Series
The “OR” function is series or parallel?
Parallel
The “NOT” function…..
Swaps positions
What are master control relays?
Master control relays are used to shut down the control power to the controls quickly for a certain machine or area of an operating plant.
