Overview of PLCs

This module provides a general overview of PLCs and their application in industry. The origins of the PLC and its evolution are covered in detail. The advantages of PLCs are also outlined, and the main components associated with PLC systems are explored. An introduction to ladder logic is presented and the most common types of PLC signals are covered with an emphasis on practical application

Learning Outcomes:

• Describe the purpose of a control panel.
• Define a programmable controller.
• List six factors affecting the original design of programmable controllers.
• Name three advantages of PLCs compared to relay logic systems.
• List the three main components in a PLC system.
• Understand the term ladder logic.
• Describe the application of PLC signals.
• Explain the difference between a bit and a word.