PLC and SCADA Training Exam

What is a PLC?

• A personal logic computer

• A microprocessor-based controller used for industrial automation

• A type of mechanical relay

• A protocol for data communication

Which of the following is NOT an advantage of PLCs?

• Rugged design

• Complexity in programming

• Designed for industrial environments

• Easily interfaced with input and output devices

What does the CPU in a PLC do?

• Stores programs permanently

• Processes input signals and executes control actions

• Powers the PLC system

• Converts analog signals to digital

Which programming language is NOT defined by IEC 61131-3?

• Ladder Diagram (LD)

• Sequential Function Chart (SFC)

• Python

• Structured Text (ST)

What does a normally open (NO) contact represent?

• The circuit is always closed

• The circuit is open when inactive

• The circuit is closed when inactive

• A special type of output device

Which of the following is a type of PLC timer?

• Continuous timer

• ON Delay timer

• Analog timer

• Sequential timer

What does the term 'latching' refer to in PLC programming?

• A temporary hold on an output

• A self-maintaining circuit

• A fault condition

• Resetting a counter

What type of counter counts down to zero in PLCs?

• Reset counter

• Down counter

• Accumulator counter

• Subtractive counter

Which of the following statements about internal relays is true?

• They are physical devices inside the PLC

• They do not exist as real-world switching devices

• They can only be used for inputs

• They cannot be programmed

In ladder logic, what does a rung represent?

• A single program line

• A connection to an external device

• An input-output interaction

• An operation in the control process