The best AI for PLC programming, compared

In 2026 there are four kinds of AI tools for PLC programming: vendor assistants (Siemens Industrial Copilot and Eigen Engineering Agent, Beckhoff TwinCAT Chat, Rockwell FactoryTalk Design Studio Copilot, CODESYS AI engineering with an MCP server, Schneider Electric PLC Code Generation Copilot), independent engineering IDEs and assistants (AnyAutomation Studio, T-IA Connect, PLC Copilot, PLC Assist, SCLcode, PLCs.ai, Copia AI), general chatbots and coding agents (ChatGPT, Claude, Gemini, Claude Code or Cursor with an MCP server for TIA Portal) and open-source and research projects (TIA Openness MCP servers on GitHub, LLM4PLC, Agents4PLC, AutoPLC). This comparison sorts 15 tools by the questions that decide in practice: for which environment? Which model, and may it run locally? How does the code get into the project, and who verifies it? What does it cost? What AI can do in PLC programming in general, and where its limits are, is in the guide to AI for PLC programming.

The comparison table

As of 22 September 2026. Statements about third-party products come from public vendor pages and documentation; the vendors' own information prevails. If a tool is missing or a statement is outdated, write to support@anyautomation.ch and we will correct it.

Vendor assistants

Siemens Industrial Copilot and Eigen Engineering Agent

Siemens offers two generations of its own AI tools for TIA Portal: the chat-based Industrial Copilot (developed with Microsoft, cloud inference, an on-premise variant is announced) and, since 2026, its agentic successor, the Eigen Engineering Agent, which connects directly to the project and delivers PLC code, HMI scripts and drive configurations, for TIA Portal V19 through V21, as a subscription on the Siemens DEX marketplace. Strengths: the deepest integration, vendor support. Limits: a fixed model, cloud data flow, no older TIA versions, no unit tests, no Git. The side-by-side with every criterion is on the page Siemens Industrial Copilot alternative.

Beckhoff TwinCAT Chat

The chat assistant inside TwinCAT 3 engineering uses OpenAI or Azure OpenAI through the user's own account and writes ST code straight into the project. An agentic successor (TwinCAT CoAgent) is announced. TwinCAT only.

Rockwell FactoryTalk Design Studio Copilot

The assistant in Rockwell's cloud IDE FactoryTalk Design Studio explains and generates logic for Logix controllers. Cloud-based, fixed model, Rockwell only.

CODESYS AI engineering and MCP server

CODESYS offers AI-supported engineering in its own IDE and documents an MCP server through which external AI clients (Claude Code or an agent of your own, for example) work with the CODESYS project. That makes the model choice free, but the connection is the user's job. All tools for CODESYS in detail: AI for CODESYS.

Schneider Electric PLC Code Generation Copilot

Schneider introduced a code generation copilot for EcoStruxure Machine Expert in late 2025. Cloud-based, fixed model, Schneider only.

Independent engineering IDEs and assistants

AnyAutomation Studio

AnyAutomation Studio is an engineering IDE for Windows that connects TIA Portal V15 through V21 over the official Openness API and CODESYS 3.5. The AI assistant knows the project (tags, data types, blocks), generates and refactors SCL, converts STL to SCL, writes unit tests and, as an agent, drives the full tool set: export, import, editing, EPLAN, live PLC, Forge. The model is yours to choose: Claude, GPT, Gemini, xAI, 20+ cloud providers with your own key, or local models via Ollama, LM Studio, vLLM and SGLang; no request passes through an AnyAutomation server. Every import shows a diff first; afterwards Studio compiles and runs SCL unit tests on PLCSIM Advanced or the real S7 PLC, with a CI/CD runner. On top: a Git client, block and project compare, PLC online over S7 and OPC UA, a password vault. Pricing is public: AI chat from Basic (CHF 10 per month or CHF 110 per year), unit tests, Forge and EPLAN from Pro+. Free 30-day trial. Limits: Windows only, TIA Portal or CODESYS must be installed locally, CODESYS is currently read-only with PLCopenXML export.

T-IA Connect

T-IA Connect by FeelAutom is an automation layer on top of the TIA Openness API with a VS Code extension and an MCP server. The AI itself is brought by the user (Claude Code or Cursor, for example); T-IA Connect exposes the operations on the TIA project. Per the vendor it covers TIA Portal V17 through V21, with an on-premise option and a test harness. Pricing on request.

PLC Copilot, PLC Assist, SCLcode, PLCs.ai and friends

A group of web and chat tools that produce PLC code from a description, explain it and help with debugging: PLC Copilot (multi-vendor, with a Siemens integration, subscription in USD), PLC Assist (TIA Portal, CODESYS, TwinCAT, subscription in EUR), SCLcode (a web generator for Siemens, Rockwell, CODESYS, Beckhoff), PLCs.ai, PLCcode.ai and PLCAutoPilot. What they share: a fixed cloud model, no project context over the vendor API, copy and paste as the path into the project, and no testing. Quick for small blocks, thin for project work.

Copia Automation

Copia is a Git-based DevOps platform for industrial automation with AI features (Copia AI). Its strength is version control and collaboration across vendors; the AI is an addition. Cloud, pricing on request.

General chatbots and coding agents

ChatGPT, Claude, Gemini in the browser

The entry point for most people: explain SCL, draft a scaffold, interpret an error. Free choice of model, from the free tier. The price is the missing project context: invented symbol names, guessed data types, copy and paste as the import. What works and where it fails is in ChatGPT for TIA Portal.

Claude Code or Cursor with an MCP server for TIA Portal

If you already use a coding agent, you can connect it to TIA Openness through an MCP server. There are several community servers on GitHub (tiaportal-mcp, for example, also as a VS Code extension), and T-IA Connect offers a commercial one. Free choice of model, agentic work, but: installation and hardening are the user's job, the servers differ widely in scope and maturity, and compile, tests and diff review are yours to organise. Background in the post MCP and TIA Portal.

Open source and research

Research supplies the benchmarks the tools are measured against: LLM4PLC (a pipeline with compiler and verification feedback), Agents4PLC (a multi-agent approach with formal checking), AutoPLC (code generation with feedback from the compiler) and the Fraunhofer project ChatPLC. The finding all four share: language models write usable IEC 61131-3 code when the compiler sits in the loop. That exact pattern (generate, compile, test, correct) is what the integrated tools put into production.

Which tool for whom

• TIA Portal V19 through V21 only, Siemens cloud is approved, official integration matters: Siemens Industrial Copilot or Eigen Engineering Agent.
• A TIA Portal estate from V15 up, local inference or a free choice of model, tests and Git are part of the job: AnyAutomation Studio.
• Your own coding agent (Claude Code, Cursor) should drive the TIA project: T-IA Connect or an open-source MCP server, plus your own gates.
• Learning, small blocks, no budget: ChatGPT or Claude in the browser, always compile the result.
• CODESYS: CODESYS AI engineering and MCP server; AnyAutomation Studio for reading, context and PLCopenXML export.
• TwinCAT or Rockwell: TwinCAT Chat or FactoryTalk Design Studio Copilot respectively.

Methodology

The comparison covers tools that are publicly available in September 2026 and generate, explain or edit PLC code in IEC 61131-3 languages. The criteria are the questions from purchasing conversations: environment, model choice, local option, path into the project, verification, pricing. Statements about third-party products rest on public vendor pages, documentation and product announcements; not all of them were tested in operation. AnyAutomation is the maker of AnyAutomation Studio.

Frequently asked questions

Which AI tools exist for PLC programming?

Vendor assistants such as Siemens Industrial Copilot and Eigen Engineering Agent, Beckhoff TwinCAT Chat, Rockwell FactoryTalk Design Studio Copilot, CODESYS AI engineering and Schneider PLC Code Generation Copilot; independent tools such as AnyAutomation Studio, T-IA Connect, PLC Copilot, PLC Assist, SCLcode, PLCs.ai and Copia AI; general chatbots such as ChatGPT, Claude and Gemini; coding agents such as Claude Code or Cursor with an MCP server for TIA Portal; plus open-source and research projects such as LLM4PLC and Agents4PLC.

Which is the best AI tool for PLC programming?

It depends on the controller, data protection and the way you work. For TIA Portal from V19 with an approved Siemens cloud, the Eigen Engineering Agent is the obvious vendor choice. For TIA Portal V15 through V21 and CODESYS with a free choice of model, local inference, unit tests and Git, AnyAutomation Studio is the most complete independent tool. For quick questions a chatbot is enough.

Is there an alternative to Siemens Industrial Copilot?

Yes. AnyAutomation Studio offers AI assistance for TIA Portal with a free choice of model, a local option and support for V15 through V21, tied to Openness, unit tests and Git. T-IA Connect is an alternative for users who want to connect their own coding agent. The detailed comparison is on the page Siemens Industrial Copilot alternative.

What is the difference between Industrial Copilot and Eigen Engineering Agent?

Two generations of the same Siemens AI line: Industrial Copilot is the chat-based assistant of the first generation, the Eigen Engineering Agent is the agentic successor that connects directly to the project and carries out tasks on its own, for TIA Portal V19 through V21 as a subscription via Siemens DEX.

Which AI tools run locally, without a cloud?

AnyAutomation Studio with local models via Ollama, LM Studio, vLLM or SGLang; coding agents with a local model and an MCP server; T-IA Connect in an on-premise variant per the vendor. The vendor assistants from Siemens, Rockwell and Schneider run over the cloud; Siemens has announced an on-premise variant of Industrial Copilot.

Which tool writes directly into the TIA project?

The Siemens tools directly in TIA Portal, AnyAutomation Studio and T-IA Connect over the official Openness API, coding agents through an MCP server. Chat and web tools such as PLC Copilot, PLC Assist or SCLcode deliver code to copy.

Which tools test the generated code?

AnyAutomation Studio runs SCL unit tests on PLCSIM Advanced or the real S7 PLC, with a CI/CD runner. T-IA Connect names a test harness. The remaining tools leave verification to the user.

Which AI tools exist for CODESYS?

CODESYS itself with AI-supported engineering and an MCP server for external clients, PLC Assist as a chat tool, SCLcode as a web generator, and AnyAutomation Studio, which opens CODESYS 3.5 projects, uses them as context for the AI chat and exports them as PLCopenXML.

Can I use Claude Code or Cursor with TIA Portal?

Yes, through an MCP server for TIA Openness: community servers on GitHub or commercially via T-IA Connect. Installation, hardening and gates (compile, tests, diff) are then the user's job. AnyAutomation Studio brings the same agentic approach with ready-made gates and a free choice of model inside one IDE.

What do the AI tools for PLC programming cost?

Chatbots from the free tier, chat tools as monthly subscriptions in USD or EUR, vendor assistants as subscriptions on the vendors' marketplaces, T-IA Connect and Copia on request. AnyAutomation Studio from CHF 10 per month (AI chat in the Basic plan), Pro CHF 30, Pro+ CHF 50, cheaper yearly, plus your own API key with the model provider or a local model with no key.