PLC and Industrial Automation Basics
Ladder logic, sensors and actuators for factory automation.
Taught by Bikash Pandey · Embedded Systems Engineer
What you'll learn
- Explain the PLC scan cycle and how it affects the way inputs are read and outputs are written
- Wire sensors and actuators to digital and analogue I/O using correct sinking, sourcing and NO/NC conventions
- Write ladder logic and Structured Text for seal-in circuits, interlocks, timers and counters
- Scale 4–20 mA analogue signals into engineering units and detect wire breaks
- Plan a clear HMI screen and read PLC data over Modbus TCP from Python
- Apply basic machine-safety principles and troubleshoot a PLC system methodically
About this course
This beginner course is a practical introduction to programmable logic controllers (PLCs) and industrial automation for students, electricians, technicians and engineers moving into manufacturing, packaging, water treatment or building services, where automation skills stay in steady demand. You will learn how the PLC scan cycle works, how digital and analogue I/O modules connect to sensors and actuators, and how to write ladder logic for start/stop circuits, interlocks, timers and counters. You will also meet Structured Text from the IEC 61131-3 standard, plan a clear HMI screen, read PLC data over Modbus TCP and learn the machine safety principles every automation technician must respect. No previous PLC programming experience is needed, although basic electrical knowledge helps. Every exercise runs on free software such as OpenPLC or CODESYS, so you can practise before you touch real hardware.
Course content
7 lessons- 1What a PLC Is and How the Scan Cycle WorksWhere PLCs fit in industry, how they differ from a PC, and the scan cycle that runs every program.Preview
- 2PLC Hardware: Power, CPU and I/O ModulesThe parts of a PLC system and how digital and analogue signals reach the CPU safely.
- 3Sensors and Actuators on the Factory FloorThe field devices PLCs read and drive, from proximity sensors to contactors, valves and VFDs.
- 4Ladder Logic FundamentalsContacts, coils, the start/stop seal-in circuit and interlocks, in ladder and Structured Text.
- 5Timers and CountersUse TON, TOF, TP and CTU blocks to add delays, pulses and counts to machine logic.
- 6HMI Basics and Industrial CommunicationDesign clear operator screens and read PLC data over Modbus TCP, with PROFINET, EtherNet/IP and OPC UA in context.
- 7Machine Safety, Troubleshooting and Your First ProjectApply safety principles, fault-find a PLC system methodically and build a complete small automation project.