First Technology Transfer

Standard and Advanced Technical Training, Consultancy and Mentoring

Ladder Logic Programming

Duration: 3 Days

Intended Audience

This course is for engineers who are new to Ladder Logic Programming, or who need to brush up on their Ladder Logic Programming skills


As well as covering the concepts and history underlying Ladder Logic, the course covers practical Ladder Logic application development using SoapBox Snap with an Arduino target, and OpenPLC Ladder Logic together with the OpenPLC runtime on a RasbperryPi based controller.

The objectives of the course are to provide a complete practical introduction to Ladder Logic at the theoretical, conceptual and practical levels.

The course is a three day course involving around 50% theory and 50% practice. The last day of the course includes a demonstration of OpenPLC ScadaBR.

Course Outline

  • Overview of number systems – binary, octal, decimal and hexadecimal
  • Overview of Boolean Logic and Boolean Algebra
  • Origins and history of PLCs
  • Introduction to Ladder Logic – Contact and Coil
  • Ladder logic symbols
    • Normally Open Contact
    • Normally Closed Contact
    • Output
    • One Shot – Positive Edge Detection
    • Timer Delay On
    • Timer Delay Off
    • Greater Than or Equal To
    • Less Than or Equal To
    • Equal To
    • Addition, subtraction, multiplication, division
  • Basic ladder logic programming and Variations Between Different Makes of PLC
    • Conceptual model of how a PLC operates
    • Defining variables for ladder logic programming
    • Logic functions - AND, OR, XOR
    • Logical Continuity
    • Electrical Continuity
    • IO Mapping
    • Examine On and Examine Off Instructions
    • Structured approaches to Ladder Logic Programming
  • Standard ladder logic programming patterns
    • The Sealed in Coil pattern
    • The State Coil/Fault Coil pattern
    • The Start/Stop Circuit pattern
    • The Set/Reset pattern
    • The Flasher pattern
    • The Debounce pattern
    • The Input Map pattern
    • The Step pattern
    • The Mission pattern
    • The Five Rung pattern
    • The Mode pattern
  • Practical PLC application development using Soap Box Automation and an Arduino UNO
  • Commercial Industrial Arduino based PLC devices
  • Practical PLC programming using OpenPLC and a RaspberryPi
  • Commercial Industrial RaspberryPi based PLC Controllers
  • SCADA and PLC – an introduction