Read this before you allow Rung Coder to modify a control project.
This Notice forms part of the End User Licence Agreement. By installing or using Rung Coder you confirm that you have read and understood it.
1. What Rung Coder does
Rung Coder connects an AI assistant of your choice (Claude, Codex, Gemini and similar tools) to the CODESYS development environment. Once you grant access, the AI assistant can, depending on the authorisation level you approve inside CODESYS:
- read your project structure, POUs, GVLs, DUTs and visualisations;
- create, modify and delete program code, variables and data types;
- change device configuration, task settings and motion-control axis parameters;
- compile the project and save it to disk;
- capture images of the CODESYS window for diagnostic purposes.
In other words: the software lets an automated system write code that may ultimately run on machinery.
2. Rung Coder is not a safety-related system
Rung Coder has not been developed, assessed or certified according to any functional-safety standard. It is not, and must not be treated as, part of a safety-related control system.
Do not use Rung Coder, and do not use code produced with its assistance, for:
- safety functions of any kind, including emergency stop, safety interlocks, light curtains, two-hand controls, safe torque off, guard monitoring or speed/position monitoring;
- any function to which a Safety Integrity Level (SIL) under IEC 61508 / IEC 62061, or a Performance Level (PL) under EN ISO 13849, has been assigned;
- burner, boiler, pressure, lifting, medical, nuclear, aviation, rail or any other application where a malfunction can reasonably be expected to cause death, personal injury, or severe environmental or property damage.
Safety functions must be developed, verified and validated using the tools and processes prescribed by the applicable standards, by qualified personnel, without AI-generated modification.
3. You remain the responsible engineer
Rung Coder is an assistance tool. It does not replace engineering judgement and it does not assume any part of your legal responsibility. You remain solely responsible for:
- reviewing and understanding every line of code before it is used;
- the risk assessment for the machine or installation;
- compliance with all applicable law and standards, including — where relevant — the EU Machinery Regulation (EU) 2023/1230, the Machinery Directive 2006/42/EC, EN ISO 13849, IEC 61508, IEC 62061 and IEC 61131-3;
- commissioning, testing, validation and hand-over documentation;
- the safety of everyone who works on or near the machine.
If you are not qualified to review IEC 61131-3 control code, do not use this software to modify a project that will run on real equipment.
4. Before you let an AI assistant modify a project
We strongly recommend the following working practice:
- Keep an independent backup. Before the first AI modification, Rung Coder automatically saves a complete project baseline on your own computer and can keep further local checkpoints for rollback. This built-in history is a recovery point for AI changes; it does not protect against disk failure, corruption or loss of the local version store. Keep a separate copy outside the working directory as well.
- Work offline or in simulation. Verify AI-generated changes in CODESYS simulation mode, or on a test rig, before downloading to real hardware.
- Disconnect from the machine. Do not let an AI assistant perform bulk modifications while the development environment is connected to a running controller.
- Review before you build. Read the diff. Compile. Read the compiler warnings — do not let them be dismissed automatically.
- Grant the minimum authorisation. CODESYS asks you to approve an access level. Use readonly for analysis; only raise it to readwrite or full_control when you actually intend the AI to change or save the project.
- Watch for silent saves. At full_control, the AI assistant can save the project without asking you again.
5. AI output can be wrong
The AI models used with Rung Coder are supplied by third parties and are not under our control. They can produce code that is syntactically valid, compiles without error, looks plausible, and is nevertheless wrong — including in ways that are dangerous in a physical process.
Known failure modes include invented function-block names, incorrect scaling and unit conversion, wrong edge/level logic, missing interlocks, off-by-one errors in array access, and confidently stated but false claims about what a piece of code does.
We make no representation that AI-generated output is correct, complete, fit for any purpose, or compliant with any standard.
6. Connected equipment and physical risk
Where Rung Coder is used with a development environment that is online with a controller, changes may take effect on real equipment. Before any such use:
- ensure the machine is in a safe state and the danger zone is clear;
- ensure a person able to trigger the emergency stop is present;
- ensure you have a tested procedure for restoring the previous program.
Never leave an AI assistant working unattended against a live process.
7. Backups and data loss
The AI assistant can delete objects, overwrite code and save projects. Before its first modification, Rung Coder automatically records a complete project baseline in a version store on your computer. You can create further local checkpoints, inspect changes and restore the project to an available checkpoint.
These recovery points exist only where you store them. We do not hold an off-device copy and cannot recover them if the computer, disk or local version store is lost or damaged. Keep an independent backup of every important project.
8. Acknowledgement
By installing Rung Coder you acknowledge that:
- you are a qualified professional user, or are acting under the supervision of one;
- you have read and understood this Notice;
- you accept sole responsibility for reviewing, testing and validating all code produced with the assistance of this software;
- you will not use this software in the safety-related applications listed in Section 2.
Nothing in this Notice limits any liability that cannot be limited by law, including liability for death or personal injury caused by negligence.
Questions about this Notice: [email protected]
CODESYS® is a registered trademark of CODESYS GmbH. We are not affiliated with, endorsed by or sponsored by CODESYS GmbH.