PLCs & Ladder Programming

What is a PLC?

• Personal Logic Controller
• Programmable Logic Controller
• Professional Logic Controller
• Permanent Logic Controller

What does a normally open (N.O.) switch do when pressed?

• It remains open
• It becomes inactive
• It becomes active
• It turns off

Which logic function requires all inputs to be true for the output to be true?

• OR
• NOT
• AND
• XOR

In ladder logic, what does an OR function do?

• Activates output if all inputs are true
• Activates output if any input is true
• Deactivates output if all inputs are true
• Deactivates output if any input is true

What is the role of a truth table in ladder logic?

• To illustrate physical connections
• To show possible input and output combinations
• To measure current flow
• To display circuit symbols

What does an AND circuit require to complete the circuit?

• Only one switch closed
• Both switches open
• Both switches closed
• One switch open and one closed

What happens in a NOT function when the switch is pressed?

• Current flows
• Current stops flowing
• Current increases
• Current decreases

Which of the following is an example of a ladder logic input device?

• Motor
• Lamp
• ON button

• Conveyor