Siemens PROFIBUS Repeaters Reach Type Cancellation — With No Functional Successor

What actually happened on 1 October 2026

Siemens manages end-of-life through a published lifecycle ladder. Two milestones matter here. PM400 is the product phase-out announcement — the point at which a product stops being actively marketed but can still be ordered. PM410 is type cancellation, the point at which the order number stops being procurable through the manufacturer channel at all.

For the PROFIBUS repeater and terminating-resistor group, Siemens' product lifecycle listing places the phase-out announcement at 1 October 2024 and the type cancellation at 1 October 2026. That two-year window is the standard lead time the company allows customers to prepare — and it has now closed.

The listed consequence is the sentence worth reading twice: no functional replacement. That is not the usual wording. Most phase-out notices name a successor platform, and the transition becomes a project. Here there is no successor part number to migrate the function into.

The order numbers affected

These are the items most commonly found in PROFIBUS cabinets built between roughly 2000 and 2015, the years when the platform was the default fieldbus in machine building, water treatment, food processing and packaging:

Note the first row carefully. The 0AA02 repeater is itself the hardware-upgraded replacement for the earlier 0AA01, which went end-of-life some time ago. The successor of an obsolete part has now become obsolete — there is no next step in that chain to wait for. That is the practical definition of a dead end for a spare part.

Always confirm the lifecycle status against the exact order number on your nameplate, not against the product family name. Siemens issues lifecycle notices per article number, and items within the same family reach milestones on different dates.

The second half of the story: ET 200 PROFIBUS interface modules

The same lifecycle cycle has reached the distributed I/O platforms that talk PROFIBUS. Siemens' product catalogue now carries a PM400 phase-out announcement effective 1 October 2026 across the PROFIBUS interface modules and DP/DP couplers of four ET 200 families. This one does have a successor direction — the corresponding PROFINET interfaces — but the successor is a different network, not a different module.

The distinction between the two halves of this announcement matters for planning. The ET 200 interface modules are in the announcement stage — still orderable, with lead times that will stretch as the remaining production runs finish. The repeaters and terminating resistors are already past cancellation. If a single audit covers your PROFIBUS infrastructure, do it now: the ET 200 items are still purchasable through normal channels today, and they are the cheapest they will ever be.

Why this hits harder than other obsolescence

Most spare parts failures are self-limiting. A CPU fails, a spare goes in, production resumes. Repeaters and terminating resistors behave differently for three reasons:

• They are single points of failure for a whole segment. One failed repeater takes down every node on both segments behind it — not one machine, but the entire cluster of I/O, drives and panels that segment carries.
• They fail quietly under electrical stress. Repeaters sit between segments precisely because those segments have different ground potentials. Age, heat and ground-loop stress degrade them gradually, and the failure often appears as intermittent communication faults before it becomes a hard stop.
• Improvisation is not safe. Substituting a passive resistor block, or wiring around a failed repeater, changes segment length, node count and termination in ways that show up later as random bus faults — the most expensive kind of fault to diagnose on a live line.

One point of context: PROFIBUS is an open standard, and third-party repeaters and active terminators for it do exist from other manufacturers. Whether a given third-party device is acceptable is an engineering decision, not a purchasing one — it depends on segment length, baud rate, topology and what the machine builder's documentation allows. Genuine parts remain the zero-engineering option, which is why stock of them is worth treating as critical spares rather than routine consumables.

How Austinovo can help

We supply genuine spare parts for legacy Siemens automation — PLC modules, HMI panels, drives and the PROFIBUS infrastructure components covered here — sourced through international channels with documented traceability. Send us the order number from your nameplate, or a photograph of the label, and we will confirm current availability, condition and delivery time, usually within 24 hours.

If you are running a wider lifecycle audit across an installed base — PROFIBUS infrastructure, S7-300/ET 200M racks, or the SIMATIC HMI panels whose supply ended on 1 October 2026 — we can review your BOM line by line and flag which items still have a manufacturer supply channel and which have moved to stock-only. Our background notes on sourcing obsolete S7-300 and ET 200M spare parts and on the HMI type cancellation of 1 October 2026 cover the same rule of thumb from different angles: verify the part, then decide fast.