Vendor-neutral · validated · runs offline

Ladder logic you can
actually run.

An AI workbench for the people who program machines. Draw a rung and watch it conduct. Ask for logic and get logic a compiler has already agreed with.

No account, no card. It runs in the browser and saves to the browser.

Live|conveyor start/stop0 scans
1Start_PBConveyorStop_PBGuard_OKConveyor2ConveyorRun_Lamp
Inputs
Outputs
ConveyorQ0.0
Run lampQ0.1
Rung 1 / 2FALSE · FALSE

Click the contacts on the rung, or the switches below. Press Start and the conveyor latches through its own contact and stays on when you let go. Stop is normally closed, so it conducts at rest and breaks the rung when pressed.

Not a picture of a ladder program. This is the same scan engine the editor uses, solving these two rungs on a timer, in your browser. Operate the switches and it behaves the way the logic says it should.

Every vendor built a copilot.
Every one of them is a cage.

Siemens will help you write Siemens. Rockwell will help you write Rockwell. Beckhoff will help you write Beckhoff. That is not a criticism. Their assistants exist to sell their hardware, and they do it well.

It leaves out the person who touches a Siemens line, a Rockwell cell and a CODESYS skid in the same week. Which is most system integrators, most contractors, and most maintenance departments in a plant that has bought equipment for more than ten years.

LADX belongs to the engineer instead of to the hardware.

How it works

Nothing reaches you until a compiler agrees it exists

A language model that has read the internet can write something that looks like ladder logic. Looking right is not the bar in a job where wrong code stops a line, or hurts somebody. So LADX does not show you an answer it has not checked.

Generate, compile, check, repairGenerateany modelCompilematiecCheckiec-checkerShown to youonly if it passeserrors go back · it tries again

It compiles for real

matiec, the open IEC 61131-3 compiler, not a regex that counts brackets. If it does not build, you never see it.

It gets checked

iec-checker for static analysis and a PLCopen schema pass, so the structure is valid and not only the syntax.

It repairs itself

Failures go back to the model with the compiler's own errors attached. This is what makes a free model good enough to be useful.

What's in it

Ten tools that share one project

They are not separate apps that export to each other. They all read and write the same representation, so the rung you draw is the rung the AI edits, the rung that converts, the rung Monitor runs, and the rung that ends up in the functional spec.

Write the logic

Draw it, ask for it, move it between platforms.

Draw it and prove it

The panel drawings, and the logic running.

Ship the project

The job around the code, and its paperwork.

All 10 in detail →

Why conversion works

Every format meets in the middle

There is no Siemens-to-Rockwell converter inside LADX, and there never will be. Everything is read into one representation built on PLCopen TC6, and everything is written out of it.

Four importers and four exporters give sixteen conversion paths for eight pieces of work: and adding a ninth vendor gives everyone else a new destination for free.

Every format meets in the middleRockwell .L5XSiemens SCLBeckhoff .TcPOUCODESYS XMLLADX IRPLCopen TC6Siemens SimaticMLRockwell .L5XStructured TextOpenPLCREADWRITE

Also, it teaches

The simulator does not lie to you

Most teaching simulators cheat: they solve the rungs like a list of equations, so a coil on rung five appears to reach a contact on rung two instantly. Then the student meets a real controller and nothing behaves the way they were taught.

LADX keeps the output image. A coil written after a contact has already been solved does not reach it until the next sweep. Edges are remembered per instruction, so a held button counts once and not four thousand times. Timers advance on elapsed milliseconds, not on how many scans happened to fit.

Which is to say: the things students get wrong are the things it gets right.

Read: what actually happens in one scan
PLC scan cycleRead inputsSolve logicWrite outputsHousekeepingRepeat1-20MILLISECONDS

Open it and draw a rung.

The editor and the simulator are free and always will be. No sign-up, no card, nothing to install.

Open Studio