rungs.dev blog

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 passed 98% of Ladder Logic tasks within five tries at low effort, using fewer tokens and costing less than Gemini-3-Flash-Preview.

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.

ChatGPT writes your whole PLC routine if you ask.

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 release notes — inline tag editing on rungs, expression-based array indexes, Logix-grade arithmetic, and printable Add-On Instructions.

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 is a browser-based PLC playground for isolating, simulating, and documenting Add-On Instructions — no hardware, no Studio 5000 license required.