Coilmind vs the Siemens Eigen Engineering Agent
The Eigen Engineering Agent is Siemens’ AI assistant for TIA Portal. Many engineers still know it by its earlier name, Engineering Copilot TIA. It is a strong product: it generates LAD and SCL, configures hardware and SINAMICS drives, builds WinCC Unified screens, translates project texts and checks code against your style guide. If your organisation is standardised on the Siemens toolchain, it will probably fit you better than Coilmind does.
This page is for everyone else: engineers on V17 or V18, people who can’t commit £1,548 for a year up front, teams working where the internet doesn’t reach, and anyone maintaining STL nobody wants to touch.
Who each one is built for
Look at what Eigen does beyond writing code: SINAMICS drive parameters, motors and encoders, device and module management, mass adaptations across dozens of blocks, style-guide conformance. That is the work of a line builder with a hardware department and a written standard.
The licence points the same way. One seat covers up to three assigned users, one at a time, managed through an Industry Organization Account, which Siemens describes as one per company. That suits an organisation that assigns and reassigns licences as people come and go.
I built Coilmind for the individual engineer who buys one licence on their own card. It is good at the work you do yourself every week: cloning a block for the twelfth conveyor, reverse-engineering someone else’s logic, translating comments for a client’s HMI, fixing legacy on site.
I don’t think either is the better product. They are aimed at different people, and the rest of this page follows from that.
If you’re on V17 or V18
Eigen requires TIA Portal V19, V20 or V21.
Plenty of machines still run on V17 or V18, because upgrading a working project is a risk nobody takes for fun. On those, Eigen isn’t an option at any price. There is no lower tier and no legacy mode, so you would have to upgrade first.
Coilmind works from V17. A 2021 project you maintain for a client with no migration plans is exactly the case it was built for. The limits: I test day to day on V19–V21, and a few conveniences, block renaming among them, need V21. On V17 and V18 the core works and the edges are thinner.
This gap won’t close with the next release. A cloud assistant tracks the current portal because that’s where the API surface it needs lives, and supporting older versions is a cost somebody has to choose to carry.
£1,548 before you know if it works
Eigen has one plan and one term: £1,548.16 per seat, billed yearly. There is no monthly option. You get a free month to decide, and then you commit to twelve.
That works if the free month happens to line up with the right kind of work. If you spend it on a commissioning trip, or on a V17 project Eigen can’t open anyway, the month is gone and the next way in is the full year.
Coilmind is €29 a month. If it doesn’t fit how you work, you’ve lost twenty-nine euros and an evening. In a quiet quarter you can drop a tier, and between contracts you can cancel and come back later, without calling anyone.
If you’d rather pay for the year you can, with two months free: €290, €590 or €1,490. Monthly stays available either way.
Also, nobody knows what this category will look like in a year. Committing twelve months to any of these tools, Coilmind included, is a bet, and paying monthly means you don’t have to make it.
Two of you, one licence
Eigen’s licence covers three assigned users per seat, but only one can work at a time. If two of you need the agent on a Tuesday afternoon, that’s two seats.
A Coilmind licence covers several machines (two, four or ten, depending on the plan) and you can work at the same time. The ceiling is requests per minute, not named seats. For a two- or three-person integrator that’s the difference between one subscription and three.
If you keep hitting the rate limit, move up a plan rather than buying a second licence.
Legacy STL
Eigen’s published capabilities cover LAD and SCL. STL isn’t in the list.
A lot of the painful work is written in it: blocks from 2008 that still run a line, that nobody wants to touch, and that come with the project you inherit. Coilmind reads STL and rewrites it into SCL or LAD. Proving the rewrite behaves the same is a workflow rather than a button: you run the original’s tests against the new version, which needs PLCSIM Advanced (Siemens sells it separately). Anything that can’t be translated cleanly is shown to you instead of guessed.
If your work is new projects on modern hardware, this section doesn’t matter to you. If your work is keeping other people’s machines running, it may be the only section that does.
Where your project lives
Eigen is a managed cloud service, and Siemens states it ensures full data privacy and sovereignty. For most companies that settles it. It’s Siemens, and they already trust Siemens with the controllers.
Coilmind is a Windows application on your machine. By default, requests go through our proxy to our inference providers, DeepInfra and Fireworks, both in the US. So with the cloud model the relevant part of your project leaves your PC too. Anyone claiming otherwise about a cloud-model tool is telling you about their control plane, not your data.
The difference is that you can switch it off. With a local model on your own hardware nothing leaves the machine, whether you’re on site or on an air-gapped network. Local models are weaker than cloud ones, and how capable they are depends on your GPU. The block templater is fully deterministic and uses no model at all, which matters where policy rules AI out.
What Siemens does better
Devices and modules, SINAMICS drive parameters, motors and encoders, PROFINET, ECAD-to-project generation. Coilmind does none of it and isn’t planning to.
Eigen creates WinCC Unified devices. Coilmind works inside devices that already exist: it builds screens and items, changes their properties, writes the JS scripts and creates the HMI tags, but it will not add the device for you. Faceplate types are beyond both of us, because Openness cannot create them.
Mass adaptations across many blocks and style-guide enforcement. Built for teams with a written standard. Volume discounts start at six seats.
For a large company, buying inside Siemens Digital Exchange against an existing agreement is far less friction than adding a vendor. That counts for a lot, and it has nothing to do with software.
Siemens makes the PLCs, the portal and the API. If Openness changes, they know first. I find out the same day you do.
There’s a support organisation behind Eigen. Behind Coilmind there’s me, answering email.
Is Coilmind right for you?
- ✓you’re on V17 or V18
- ✓you buy your own tools and £1,548 up front isn’t how you buy them
- ✓you want to pay monthly and stop when work is quiet
- ✓two or three of you would share one subscription
- ✓you work where the internet doesn’t reach
- ✓your weeks are spent on blocks, legacy code and translation
- ✓you inherit STL
- —your bottleneck is hardware, drives or PROFINET
- —you need HMI devices created for you
- —you need style-guide enforcement across a big codebase
- —you have more than a handful of engineers and volume pricing matters more than terms
- —you’re an organisation where staying inside Siemens procurement is worth the difference
Try it against your own project
Fourteen days, no card, twenty-five tasks included. Open a project you already know and ask for something you’d normally do by hand.
Eigen has a free month too. If you’re deciding between them, run both. Within an afternoon you’ll know which one fits how you work.
Start free trial