Industrial Automation

The Benefits of IO-Link Technology for Automation Systems

Julian Vosseler

Companies far and wide have come to appreciate IO-Link technology for its easy installation as well for being the first standardized protocol of its kind, resulting in its increased implementation in fieldbus systems established in the market. This makes the fieldbus-independent IO-Link standard the ideal solution for many companies, as it allows them to connect products to different systems and controllers worldwide.

IO-Link technology was developed to add this kind of flexibility and cost efficiency to automation applications. If you’re not familiar with this technology and how it works, keep reading.


What Is IO-Link?

IO-Link refers to the first standardized I/O technology worldwide (IEC 61131-9) that allows for communication between smart sensors, actuators, and IO-Link IO Hubs. This powerful point-to-point communication is based on the long established 3-wire sensor and actuator connection, but without requiring specific cabling material (e.g., no shielding is necessary). IO-Link is not fieldbus; instead, it came out of the continued development of existing, tried-and-tested technology for sensors and actuators.


An IO-Link system architecture will include the following, as pictured below.

  • IO-Link devices (e.g., hubs, sensors, actuators)
  • IO-Link master
  • Power/data connections


                 io-link system schematic


IO-Link Master and IO-Link Hub

The most complex components in an IO-Link system are the IO-Link Master and the IO-Link Hubs. Let’s dive into each a bit more.


The IO-Link Master simplifies the work of system engineers by making it possible to use one smart sensor or actuator for different types of applications. As seen in the image above, the IO-Link Master has eight IO-Link ports and each port couples to one IO-Link Hub. The hubs can then transmit digital signals from connected sensors/actuators through the IO-Link to the Master. This adds the benefits of increased efficiency and connectivity.


In the past, IO-Link Masters could connect up to 16 digital signals by connecting to each of the 16 sensors or actuators directly. With recent technological advancements, IO-Link Masters can now connect – in combination with IO-Link Hubs – a total of 132 I/O connections per system!


Aside from the obvious benefits that come with an increase in the number of connected I/O devices, utilizing newer IO-Link technology offers perhaps a more important benefit to the automation process: a standardized protocol between all IO-Link Hubs and Masters that replaces proprietary modular systems and supports faster machine startup and shorter maintenance cycles.


IO-Link Technology: Solving Today’s Automation Challenges

3 Benefits of IO-Link Technology:

  1. Increased efficiency
  2. Reduced downtime
  3. Simplified standardization

Advancements in IO-Link technology are enabling these benefits and meeting the following three automation industry challenges head on.

  1. Standardization – As the automation industry grows to adopt newer technologies, inevitably so too grows the number of proprietary products and technology variations. But don’t worry. You don’t have to use a wide range of differing and expensive products to embrace innovation. Maintaining a future-proof and simplified standard in automation is essential for the growth of your smart factory. IO-Link technology was developed to meet this challenge.

  2. Demand for Skilled Labor – There currently exists a high demand for specialized and qualified application specialists to maintain automation systems. When IO-Link systems are proprietary, the search for a specialist who’s fluent in the inner workings of your specific IO-Link system can become harder. Updating your IO-Link system to a newer, more efficient standard means that your system will be easier to service, without complex and often outdated software slowing down the specialists assigned to it.

  3. Transparency – Across the business world, transparency is one of the most important practices for well-organized and responsible operations. In an automation setting, a greater amount of transparency means keeping a keen-eye on what’s working – and what’s not working – in your factory. Through IO-Link technology, with an IO-Link Master as a means for continuous connection with the higher PLC, there’s an increased amount of transparency to see different system activity from the PLC down to the sensor and actuator level.

Ensure Your IO-Link System Is Working For You

Aside from its aforementioned benefits in automation applications, the adoption of IO-Link technology brings with it other valuable benefits that make it attractive as a new standard in your automation processes. Consider these added benefits when upgrading your system:

  • Utilize Current Cabling – When upgrading to an IO-Link system, there’s no need for new or proprietary cabling – conventional unshielded M12 3- or 5- pole standard connectors can be used. If the application calls for a proprietary form of cabling, be wary. The efficiency and future-proofing of your automation system could suffer.

  • Automatic Device Identification – IO-Link Masters and Hubs should offer some sort of integrated device identity function that, in case of device exchanging or replacing, ensures no wrong or incompatible IO-Link device can be coupled. Without this feature, troubleshooting connections could erode your uptime.

  • Simplify Orders – Your purchasing and procurement department will thank you for fewer orders overall and, with IO-Hubs that are multipurpose, one type of device can perform a greater number of tasks. This means fewer product ID numbers to keep track of. Not to mention the pricing discounts that can be offered when larger quantities of the same product are ordered at once.

  • Tidy Up Storage Space – Adopting an IO-Link system standard and replacing proprietary modular systems will decrease the variety of items that you’ll need to keep stocked, freeing up storage space for spare parts.

  • Simplify Replacement – IO-Link standardization means fewer parts to train on, easier module replacements and ultimately less downtime. This simplifies machine design, installation and maintenance, along with increasing overall efficiency and cost savings.

  • Multipurpose Use – Depending on the manufacturer, IO-Link Master ports can be multi-functional for digital input or digital output, which allows for a wide variety of configurations for multi-purpose use.

We’re already seeing the adoption of IO-Link technology provide these benefits and more for numerous industries that rely on automation – from machine building and manufacturing to transportation.


Are you currently utilizing this new IO-Link standard in your automation setting? How could IO-Link Master and IO-Link IO Hub technology improve your current automation system?


To learn more about IO-Link technology, and how it fits into the incoming wave of “plug and produce” technology, download Belden’s white paper: “The Road to Plug and Produce."