How do you migrate from PROFIBUS to PROFINET without shutting down production?

5 min read

Since 1 October 2026, Siemens has been phasing out the PROFIBUS interface modules of the SIMATIC ET 200SP, ET 200MP, ET 200AL and ET 200pro, as well as the DP/DP coupler. They can be ordered new until 1 October 2027; after that, they are only available as spare parts. For many installations in the process industry, this is the moment to look beyond the next breakdown.


Why extra stock does not solve the problem

The first reflex to a phase-out is understandable: order extra components and put them on the shelf. That buys time, but it does not solve three things.

Electronics age even when they are not in use. Capacitors dry out and batteries run flat, even in a box in the warehouse. A spare module that is installed for the first time after years is no longer a new module.

The knowledge disappears too. Technicians who can quickly trace a PROFIBUS fault are becoming scarcer. A module in stock is of little help if nobody can diagnose it quickly any more.

The protocol is reaching its limits. Siemens itself indicates that PROFIBUS cannot deliver the short response times that many modern processes require.

Postponing feels safe, but it is not. The longer you wait, the greater the chance that a breakdown, rather than your own planning, determines the order of your migration.


A migration does not start with the modules

Most projects start with the question of which modules need to be replaced. That is a logical question, but it is the second one.

The first is: what does your installation actually look like? Which assets are obsolete now or will be soon, which production lines are most critical, and what dependencies exist between control, network and field devices?

"In our conversations with clients, the question is not which modules are obsolete today. The question is which choices will keep the installation safe, reliable and manageable twenty years from now. Replacing only what is outdated is a repair. Making the complete system future-proof is thinking ahead." Sebastiaan Balk, sales manager at Batenburg


From PROFIBUS to PROFINET: how we approach it

1. Insight into assets, risks and dependencies

We map your installation: which controllers, I/O stations and network components are running, what their lifecycle status is and where the risks lie. In installations that have been expanded over the years, far from everything is documented. That is why we combine existing documentation with on-site inspection and the knowledge of your own operators and technicians. This shows you which lines need attention first.


2. A roadmap that fits your shutdowns

Based on that insight, we draw up a roadmap: which parts you migrate when, in what order and with what budget. Where possible, we link the migration to shutdowns that are already planned. That way you can plan investments in a targeted way, and no breakdown determines the order.


3. Preparing, testing and converting

The shorter the conversion, the more important the preparation. We test as much as possible in advance, with simulations and a detailed I/O test plan, so that the switchover itself brings as few surprises as possible. Software, hardware and E&I all come from a single source, so they fit together instead of being designed separately.


Migration is also a security moment

With PROFINET, field communication moves to Ethernet. This makes your installation easier to connect to monitoring, data platforms and MES, but it also increases the attack surface. A migration is therefore the ideal moment to set up network segmentation, access control and monitoring properly from the start, rather than afterwards.

If your organisation falls under NIS2, you must be able to demonstrate that you control the risks in your OT environment. Components that are no longer supported make that more difficult.


What this looks like in practice

Migration in a single conversion week

At ADM Wild Netherlands in Amsterdam, Batenburg replaced a decades-old Siemens control system with Rockwell PlantPAx. PROFIBUS segments were converted and tested in advance, so the conversion could be completed in seven days. Read more (in Dutch)


An OT migration without a manual

At Polyvantis in Bergen op Zoom, Batenburg rebuilt all production systems after the company became independent, with hardly any documentation of the existing installation. Read more


Existing installations ready for the future

In the Port of Rotterdam, Batenburg modernised seven shore power cabinets with new PLC control and upgraded communication technology, ready for remote management and monitoring. Read more (in Dutch)


Where do you start?

Not with an order for extra modules, and not with a complete conversion either. Start with insight.

Once you know which assets are obsolete, which lines are critical and which shutdowns are coming up, it becomes clear what needs to happen first, what can wait and what it will cost. Eight questions to get you started are in our risk check.

Automation means thinking ahead. That is how we help our clients keep their lead. Today and tomorrow.


Schedule a consultation Download the risk check

Frequently asked questions

The PROFIBUS interface modules of the SIMATIC ET 200SP, ET 200MP, ET 200AL and ET 200pro, and the DP/DP coupler. Siemens moved them into the phase-out stage (PM400) as of 1 October 2026. The exact article numbers are listed in the official Siemens announcement.

Until 1 October 2027. After that, Siemens will only supply them as spare parts.

PM400 is the stage in the Siemens product lifecycle in which the phase-out has been officially announced. The product can still be ordered new, but the end is in sight. It is followed by a stage in which it is only available as a spare part.

As a bridge, it can help; as a solution, it cannot. Electronics also age on the shelf, and the expertise to fix PROFIBUS faults is becoming scarcer. Use stock to buy time for a planned migration, not to postpone it.

No. A phased approach per line or section of the installation is often wiser. Gateways allow PROFIBUS and PROFINET sections to coexist temporarily. The roadmap determines which sections go first.

Migrating with no downtime at all is rarely possible, but you can limit and plan the downtime. By testing as much as possible in advance and linking the conversion to planned shutdowns, the impact on your production remains manageable.

With PROFINET, field communication moves to Ethernet. That calls for a well-thought-out security design. If your organisation falls under NIS2, a migration is the moment to set up segmentation and access control in your OT environment properly from the start.

That depends on the size of your installation and the shutdowns available to you. For larger installations, the work is often spread over several planned shutdowns. The roadmap shows in advance what is realistic.