Industrial Controls and PLCs D2L

Question 1

What devices make decisions based on the machine conditions?

Answer 1

Logic devices

Question 2

True or False;
Switches are an example of a discreet signalling device.

Answer 2

True

discreet output - either on or off

Question 3

What device is used to provide actuation of a temperature switch?

Answer 3

Bi-metallic Strip

Question 4

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?

Answer 4

Interlock Switch

Question 5

Select the output device from the list below.

A) Pilot light
B) Photocell
C) Temperature sensor
D) Limit switch

Answer 5

Pilot light

Question 6

True or False;
A relay uses high voltage to switch a low voltage circuit on or off.

Answer 6

False

Question 7

What causes an electrical relay to activate or change states?

Answer 7

Magnetism in the coil

Question 8

How is a latching relay signalled to unlatch?

Answer 8

When power is sent to the unlatching coil

Question 9

True or False;
Relay logic is also known as hardwired logic because the logic is determined by the wire connections.

Answer 9

True

Question 10

Which type of logic system generally can be modified more quickly?
-Relay logic
-Programmable Logic Control(PLC)

Answer 10

Programmable Logic Control (PLC)

Question 11

What component of a PLC analyzes the inputs to determine the output requirements?

Answer 11

Processor

Question 12

What component of a PLC system is used to protect the processor and modules from low voltage conditions?

Answer 12

Transient Surpressing Transformer

Question 13

When would an input with the instruction XIC become true?

—] [—

Answer 13

When the input became closed
XIC - examine if closed

Question 14

If a PLC had a problem with an output module, how would the PLC indicate the problem to the person troubleshooting the problem?

Answer 14

flashing I/O status light

Question 15

A pressure switch asks, Is the pressure 100 psi? What is the answer?

Answer 15

Yes or No
Different types of pressure switches;
Compressed air pressure
Low air pressure
Steam pressure
Water pressure
Hydraulic pressure

Question 16

What are proximity switches used for?

Answer 16

Proximity switches are used for non-contact detection of non-metallic and metallic objects.

Question 17

What is meant by number of poles?

Answer 17

Number of poles describe how many separate circuits are controlled by a switch.

Question 18

What are throws?

Answer 18

Throws are the number of positions a switch can adopt.

Question 19

.
/o___________ Cr1-1
/
______o/………o_________Cr1-2

What is this?

Answer 19

a shit drawing of Single Pole Double throw relay.

Question 20

Solid State relays have;

Answer 20

-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)

Question 21

The “AND” function is series or parallel?

Answer 21

Series

Question 22

The “OR” function is series or parallel?

Answer 22

Parallel

Question 23

The “NOT” function…..

Answer 23

Swaps positions

Question 24

What are master control relays?

Answer 24

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.