sercos.org

What is Sercos?

Sercos is an industrial automation bus — a digital communication system that connects motion controllers, drives, I/O devices and other machine components so they exchange commands and feedback in real time. It is maintained by Sercos International e.V. as a vendor-independent standard rather than a single manufacturer's proprietary network, and the official site describes it as combining real-time behavior with IoT connectivity under the phrase "One Bus Fits All." More than half a million installed applications are cited on Sercos Automation Bus.

What it does

An automation bus carries the cyclic data that keeps a machine coordinated: position setpoints going out to drives, actual position and status coming back, and synchronization signals that keep multiple axes moving together. Sercos is aimed at motion-control applications where that timing has to be deterministic — packaging lines, machine tools, printing and converting equipment, robotics and similar multi-axis machinery. The site groups its material under Technology, Certification, Products and Applications, so the ecosystem includes both the technical specification and a certification program for conforming devices.

A newer development is Sercos over TSN, which the site presents as moving the bus into standard Ethernet-based time-sensitive networking — relevant if you want converged network infrastructure rather than a dedicated motion bus.

Who it is for

• Machine builders and OEMs choosing a network for a new multi-axis machine, who need to know which drives and controllers are available before committing.
• Control and automation engineers integrating drives, I/O and safety devices from more than one supplier.
• Device vendors considering certification and membership, since conformance testing is part of how interoperability is maintained.
• Technical managers comparing bus systems on performance, vendor support and long-term availability.

Trade-offs to weigh

Sercos' strength is determinism and multi-vendor interoperability backed by certification. The practical cost is that it competes with other established industrial Ethernet systems, so your choice may be constrained by the controllers and drives you already use, your engineers' existing skills, and what your customers or integrators expect. A vendor-independent standard reduces lock-in but does not by itself guarantee that every function you need is implemented identically across every certified product.

A useful next step

If you are evaluating it for a project, start from the applications and products sections of Sercos Automation Bus to check whether drives and controllers matching your axis count and performance class actually exist, then read the comparison page to see how it is positioned against alternatives. If you are a vendor rather than a user, the membership pages explain certification, documentation access and joint marketing.

How does Sercos compare to other industrial Ethernet protocols like EtherCAT or PROFINET?

Sercos is best understood as a real-time automation bus that now positions itself as “Real-Time + IoT,” with a membership-based, vendor-independent governance model. EtherCAT and PROFINET are the two protocols most often weighed against it when a machine builder or plant engineer is choosing a motion-control network.

Where the differences show up

• Governance and vendor independence. Sercos is stewarded by a member organization, and the site emphasizes that members gain information advantages and can influence technical direction. EtherCAT is driven by the EtherCAT Technology Group; PROFINET by PROFIBUS & PROFINET International. In practice this matters when you want a say in roadmap decisions or need documentation beyond what is public.
• Positioning. The Sercos site frames the technology around high performance, standards conformance and long-term investment safety, and explicitly offers a “Sercos in comparison” discussion of benefits versus other automation buses. That framing tells you the intended audience: engineers evaluating multi-vendor motion systems, not just single-vendor drive stacks.
• Convergence with standard Ethernet. Sercos over TSN is presented as a new era in industrial communication. TSN convergence is also a direction EtherCAT and PROFINET ecosystems have pursued, so this is less a unique differentiator than a shared trajectory — the useful question is which one your drive and controller vendors actually ship today.
• Ecosystem breadth. This is where the practical trade-off usually lands. EtherCAT and PROFINET have very large installed bases and broad device catalogs. Sercos reports over half a million installed applications, which is substantial but narrower; expect fewer third-party options and check availability for the specific servo drives, I/O and safety modules on your bill of materials.

A concrete decision scenario

Suppose you are specifying a multi-axis packaging machine with drives from two vendors and a controller from a third. Sercos is worth evaluating if your shortlisted drive vendors already offer Sercos interfaces and you value the member-driven standards process. If your shortlist is dominated by vendors whose catalogs are EtherCAT- or PROFINET-first, the integration effort and spare-parts path will usually favor those protocols regardless of technical merit.

Next step

Before committing, ask each candidate vendor for three things: a current interface option for the exact drive model, a reference installation in your machine category, and a written statement on TSN roadmap timing. Then read the comparison material at Sercos Automation Bus alongside the equivalent pages from EtherCAT Technology Group and PROFIBUS & PROFINET International, and score them against your own bill of materials rather than against general performance claims.

What are the benefits of becoming a Sercos member?

Membership in Sercos International is aimed at companies that build, integrate or specify Sercos-based motion-control and automation products, and it bundles influence, information and joint marketing rather than access to the technology itself. The specification and much of the public material are open; what membership adds is a seat at the table and material that is not published openly.

What membership gives you

• Influence over technical direction: members can contribute to how the technology develops, which matters if your roadmap depends on Sercos features or certification requirements.
• Member-only documentation: access to specific documents that are not part of the public downloads area, which shortens the gap between public specifications and implementation detail.
• Joint marketing: subsidized, shared marketing activities and the option to appear in joint Sercos booths at trade shows.
• Event visibility: exhibiting products or speaking at Sercos-sponsored conferences and events, useful for reaching integrators and machine builders who already standardize on the bus.
• Community and contacts: direct connection to other member companies through the association's channels, including its social media and the Sercos Automation Bus wiki and downloads.

Who benefits most

Practical next step

Check the membership costs overview and the membership form on the site, then decide against a concrete goal: for example, whether you need a booth slot at a specific show or access to a particular document before your next product release. If neither applies within the next year, follow the news and downloads instead — note that Sercos North America is being dissolved effective May 31, 2026, so regional support routes may change.

How does Sercos over TSN work and what advantages does it offer for industrial communication?

Sercos over TSN extends the Sercos automation bus onto Ethernet networks that use Time-Sensitive Networking, so real-time motion control and standard IoT traffic can share one infrastructure. The Sercos site frames this as "a new era in industrial communication" and sums up the technology as "Real-Time + IoT" — meaning deterministic, cyclic control data and less time-critical data (diagnostics, configuration, IT/cloud connections) travel over the same physical network. In practice, TSN's scheduling and traffic-shaping mechanisms reserve bandwidth and time slots for the control traffic, while ordinary Ethernet traffic uses what remains. Sercos remains the real-time automation bus layer on top; TSN is the standardized Ethernet foundation beneath it.

What that changes on the factory floor

• One network instead of several. Machine builders and plant operators who previously ran separate fieldbus and Ethernet networks can converge them, reducing cabling, switches and gateways.
• Standards-based, vendor-independent. Because TSN is an IEEE Ethernet standard and Sercos is an open, vendor-independent technology, you are not locked into one automation vendor's proprietary real-time Ethernet variant.
• Scalability across machine generations. Existing Sercos know-how, device profiles and certification practices carry over, which matters if you already have Sercos drives and controls in service.
• IoT without disturbing control. Higher-level data collection, remote diagnostics and analytics can run alongside motion control without competing for the deterministic channel.

Trade-offs to weigh

• Ecosystem maturity. Sercos over TSN is presented as a forward-looking development; the installed base of classic Sercos interfaces is far larger than TSN-capable installations, so device availability and multi-vendor interoperability should be checked per project.
• Engineering effort. TSN configuration (time synchronization, stream reservation, traffic classes) is more demanding than plugging in a conventional fieldbus. Your network engineers need to understand the schedule, not just the topology.
• Switch and device requirements. TSN features must be supported along the whole path, so legacy Ethernet hardware in the middle can undermine the guarantees.

A practical next step

If you are evaluating this for a machine or line, start with one concrete axis or cell: list the devices involved, confirm which of them are TSN-capable, and ask each vendor for evidence of Sercos-over-TSN conformance rather than a general TSN claim. Then compare that against keeping your current fieldbus and adding a separate Ethernet path — for small, stable machines the second option is often cheaper, while for lines with heavy diagnostics and IT integration the converged approach pays off.

For background and comparison material, the Sercos organization publishes technology, certification and product information, and a comparison of the bus against other systems at Sercos Automation Bus. General TSN framing and standards context is available from the IEEE 802.1 working group at IEEE 802. If your control platform is vendor-specific, the vendor's own documentation — for example Bosch Rexroth for ctrlX — is the better place to confirm which Sercos-over-TSN features are actually implemented in a given drive or controller.

What types of motion control applications can benefit from using Sercos?

Sercos fits applications where drives, I/O and controllers must exchange data deterministically while also exposing data to higher-level IoT systems. Its own framing is "Real-Time + IoT," and the bus is positioned for industrial motion control with a large installed base.

Where it tends to pay off

• Multi-axis coordinated motion — printing, packaging, converting, textile and wire machinery, where several servos must stay synchronized within a tight cycle.
• High-dynamic single-axis work — pick-and-place, Cartesian robots and feed axes that need short, consistent cycle times rather than high average throughput.
• Machines with many distributed drives and I/O — ring topologies let you run one cable through the machine and keep wiring simpler than star-wired fieldbus layouts.
• Retrofits and multi-vendor builds — because the technology is vendor-independent and standardized, an OEM can source drives from different suppliers without rewriting the motion layer.
• Lines that need both control and diagnostics — cross-communication lets controllers and drives exchange data directly, which suits condition monitoring and remote service.
• Converged plant networks — "Sercos over TSN" targets cases where motion traffic and general Ethernet traffic share one infrastructure.

Where it is a weaker fit

• Simple, low-axis-count machines — a few sensors and one small drive are often cheaper and faster to commission on a simpler bus or plain Ethernet I/O.
• Battery-powered or very cost-sensitive consumer devices — the ecosystem assumes industrial drives and controllers.
• Teams with no Sercos experience and no local support — training and tooling costs can outweigh the technical gains. Note that Sercos North America is being dissolved effective May 31, 2026, so North American users should confirm where support and membership activity will sit.

How to decide

Ask three questions: How many axes must be synchronized, and how tightly? Will the machine also need data pushed to IT or cloud systems? And can your drive suppliers and integrators support the bus locally? If the answers are "several axes," "yes" and "yes," Sercos is worth evaluating against EtherCAT and PROFINET IRT.

A practical next step is to check the technology and comparison pages at Sercos Automation Bus and watch the application videos listed there, such as the multi-carrier and drive examples, to see whether the demonstrated machine types resemble yours.

What are the costs and requirements to join Sercos International?

Joining Sercos International e.V. is aimed at companies that build, integrate or specify Sercos-based motion-control products rather than at individuals seeking a casual community account. The organisation presents membership as a way to support and influence a vendor-independent automation bus, with benefits that mix technical access and joint marketing.

What membership gives you

• Member-only access to specific documentation, which the site frames as an information advantage.
• A say in the direction of technical development.
• Joint, subsidised marketing activities, including shared Sercos booths at trade shows and opportunities to speak at Sercos-sponsored conferences and events.
• Use of the Sercos membership form to apply.

Requirements and costs

The site does not publish a specific fee figure in the information available here. It states only that an overview of membership costs can be found on the website and that you download the membership form to join. So the practical requirement is to complete and submit that form; the exact annual fee, category and any turnover- or product-dependent conditions need to be confirmed with Sercos International directly before you budget for it.

A useful next step

Download the membership form and, at the same time, ask Sercos International for the current cost overview and membership categories. If you are an individual engineer rather than a company, ask whether an observer or associate route exists, because the listed benefits assume an organisation that exhibits, markets products or contributes to technical work.

For background on the technology itself, the organisation's own site is the primary reference: Sercos Automation Bus. Related industrial networking standards bodies include ODVA and Ethernet POWERLINK, which are useful comparison points if you are deciding between bus systems.