PLC Hardware Componets

Question 1

The term “Hardware” in a PLC application refers to what?

Answer 1

The mechanical, electrical and electronic devices

Question 2

What componets make up a PLC?

Answer 2

1. Central Processing Unit (CPU) or Processor
2. Power Supply
3. I/O Modules

Question 3

How are PLC Power Supplies selected?

Answer 3

According to the current requirements of the modules in the assembly

Question 4

In an application where an existing assembly needs a second expansion, will the second chassis need its own power supply or will the supply for the original assembly suffice?

Answer 4

The second chassis will need its own power supply

Question 5

What is the moveable tab mounted on the back of the modules that provides communication and DC power to the individual I/O modules called?

Answer 5

The Bus Connector

Question 6

Where is the power Supply of a Compact Logix PLC located?

Answer 6

Anywhere between the second and fourth position

Question 7

Where is the CPU module of a Compact Logic PLC positioned on the assembly?

Answer 7

Position 1 of the first asembly

Question 8

What is the purpose of a battery on a PLC module?

Answer 8

To keep the program intact when a power outage occurs

Question 9

True or False, PLC power supplies may be installed in any slot on the assembly?

Answer 9

False

Question 10

What is the purpose of a battery “on power failure” in a PLC?

Answer 10

to supply power to the central processing unit (CPU) so that the program stays in memory

Question 11

If the processor RUN, LED is “OFF” what could the program be doing?

Answer 11

The processor could be in Program Mode

Question 12

What is the main function of a PLC Processor?

Answer 12

1. Read Inputs
2. Solve Ladder Logic
3. Update Outputs

Question 13

What type of PLC module would a limit switch be connected to?

Answer 13

Discrete input module

Question 14

What type of PLC module would a solenoid be connected to?

Answer 14

Discrete output module

Question 15

What is a Peripheral device?

Answer 15

Refers to equipment that is auxilary to the PLC

Question 16

Using 16 point 120V output cards with the Compact Logix processor, what is the maximum current for each output and the total per card?

Answer 16

The maximum current for each output is 0.5A, up to a total of 4A per card

Question 17

What does Input modules do?

Answer 17

They provide data for the processor

Question 18

What do Output Modules do?

Answer 18

Receive data from the Processor

Question 19

What are the three key positions a Compact Logix CPU module?

Answer 19

1. Run
2. Remote
3. Program