🧩 PLC Functions & OOP0%
🧩 The Suspiciously Fun PLC Series · Cross-brand

Functions & OOP:
from one block to a whole machine.

You know what a function block is. Now you learn to build with them the way a software engineer would: FCs for pure math, FBs for stateful machines, then the full TwinCAT 3 / CODESYS object toolkit of METHODs, PROPERTYs, INTERFACEs, IMPLEMENTS and EXTENDS, with a chapter on ACTIONs along the way. There are nine chapters with a live widget in each, ending in one complete OOP sorting machine, plus a mastery appendix.

Reuse, not copy-paste

🧬 write a block once and clone it twelve times, then give it verbs with METHODs and guard its fields with PROPERTYs. Working this way is what keeps a 200-line program from turning into a 2,000-line tangle.

Real OOP for PLCs

🏛️ INTERFACE, IMPLEMENTS and EXTENDS aren't just for app developers. You'll drive an HMI loop over 20 mixed devices through one I_Device contract, using the same patterns that run on plant floors today.

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Vendor-neutral where the standard allows. FC and FB are IEC 61131-3; METHOD, PROPERTY, INTERFACE, IMPLEMENTS, EXTENDS, THIS^ and SUPER^ are the OOP extensions in IEC 61131-3 (3rd ed.), implemented in TwinCAT 3 and CODESYS. Every keyword is shown exactly.
Best after PLC Programming Essentials: you should already know what a POU and an FB instance are.