Professional IEC 61131-3 Programming Patterns: Developing Structured PLC Applications Using Standardized Industrial Programming Languages

Build PLC applications that are easier to read, test, maintain, and extend. This practical guide focuses on IEC 61131-3 programming as it is used in real industrial projects, with patterns that support structured design rather than one-off code fragments.

Written for engineers who work with Structured Text, Ladder Diagram, Function Block Diagram, and Instruction List, the book explains how these languages fit into a coherent development approach. It covers scan cycle behavior, deterministic execution, data types, type conversion, and safe numeric handling, then moves into architecture choices that keep large control systems organized.

What you will learn

• How to separate I/O handling, control logic, and higher-level behavior
• How to design clean interfaces for programs, functions, and function blocks
• How to model sensors, actuators, states, commands, diagnostics, and faults
• How to build reusable function blocks with clear contracts and predictable behavior
• How to manage startup, reset, latching, enable cycles, and controlled recovery
• How to implement sequencers, timers, interlocks, watchdogs, and fault handling
• How to structure communication handshakes and consistent data exchange
• How to apply practical control patterns such as PID, mode switching, and scaling
• How to test, simulate, trace, and debug PLC logic with repeatable methods

The book also includes end-to-end examples that connect requirements to code, showing how individual patterns work together in a full PLC application. Rather than treating control logic as isolated snippets, it emphasizes contracts, state management, dependency control, and traceable design decisions.

Ideal for: PLC programmers, automation engineers, controls developers, and technical teams building industrial applications that need clarity, consistency, and long-term maintainability.

From first scan behavior to complete system integration, this is a hands-on reference for writing PLC code that performs reliably on the plant floor and remains understandable months or years later.