rungs.dev blog
PLC programming articles and rungs.dev release notes: Ladder Logic, Structured Text, timers, and what's new in the simulator.
What Data Taught Me About Testing Time-Based PLC Logic
What timing exercises taught me about test design, useful failure messages, and building a better way to learn Ladder Logic and Structured Text.
GPT-5.6 Luna is my new favorite model for Ladder Logic
GPT-5.6 Luna passed 98% of Ladder Logic tasks within five tries at low effort, using fewer tokens and costing less than Gemini-3-Flash-Preview.
Why Gemma-4-31B is a gem for PLC logic — and why I couldn't ship it
I benchmarked a dozen LLMs on generating Ladder Logic and Structured Text by compiling and running every answer, not by asking another model whether it looked good. Gemma matched Gemini for a tenth of the price — then no host would serve it the way that made it good.
Why Relay reads your PLC logic better than ChatGPT
ChatGPT writes your whole PLC routine if you ask. Relay won't — it reads your live ladder logic and tests in Rungs Studio and teaches one step at a time.
AI-assisted PLC learning
How Relay, the AI tutor in Rungs Studio, teaches PLC by reading your code, speaking your language, and showing you the design choice instead of defending one answer.
Rungs Studio 0.7.0
Rungs Studio 0.7.0 release notes — inline tag editing on rungs, expression-based array indexes, Logix-grade arithmetic, and printable Add-On Instructions.
Ladder Logic Editor
A Ladder Logic editor is coming to Rungs Studio — visual rung-based editing alongside Structured Text in the same browser-based PLC simulator at rungs.dev.
rungs.dev Manifesto
rungs.dev is a browser-based PLC playground for isolating, simulating, and documenting Add-On Instructions — no hardware, no Studio 5000 license required.