Plc4m3

Over 50,000 units sold on AliExpress/Etsy using their open-source code. Success rate went from ~40% to 95%+.

Let’s break down the projects that made PLC4M3 a household name (in modding circles). plc4m3

: A graphical language resembling electrical relay diagrams. Over 50,000 units sold on AliExpress/Etsy using their

| Section | What it gives you | |---------|-------------------| | /discover | Auto‑discovers PLC symbols and caches meta‑data. | | subscribers dict | Reference‑counted subscription list – multiple UI sessions can watch the same tag without redundant reads. | | read_and_broadcast | A single background loop polls once per interval, then fans‑out to every client. This is far more efficient than opening a socket per client. | | WebSocket API | Real‑time push (no polling from the browser) and a tiny JSON contract ( action, tag ) that’s easy to extend (e.g., “set‑value”, “write‑once”). | | Immediate snapshot on subscribe | UI shows the current value instantly, avoiding the first‑tick delay. | | Optional historian hook | Add a call inside read_and_broadcast to write each value to InfluxDB, then expose a /historian/query endpoint for back‑fill. | : A graphical language resembling electrical relay diagrams