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Unlocking IO-Link: What it is and Why it Matters for Modern Automation

June 24, 2024
IO-Link enhances process transparency and seamlessly integrates into existing control architectures. But what exactly is it, and why is it essential for modern industrial automation?

The use of IO-Link as a communication protocol in industrial plants has seen remarkable expansion over the past several years.

The total number of installed IO-Link nodes reached 51.6 million by the end of 2023, according to the industry trade group PROFIBUS & PROFINET International’s (PI’s) annual survey of newly installed nodes. Last year, 15.9 million IO-Link devices were installed, which represents a record growth of 89% compared to the 8.4 million devices installed in 2022.

The growth should come as no surprise to any plant already using IO-Link to expand access to the lowest field level machine and equipment data, including configuration data, identification data and diagnostics.

What Exactly is IO-Link?

IO-Link is the first globally standardized input/output technology designed for communicating with sensors and actuators and for connecting to an automation system.

Unlike fieldbus, it is not a proprietary communication protocol, but rather a recognized international standard (IEC 61131-9) that ensures compatibility and interoperability between devices from different manufacturers.

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As described in IEC 61131-9, IO-Link is a point-to-point communication protocol, which means it connects two devices directly. This makes it straightforward to implement because it uses the same cables and connectors that engineers are already familiar with.

IO-Link provides bidirectional communication. In other words, data flows both ways between the control system and field devices. The setup provides real-time process data and diagnostic information from the sensors and actuators, enabling more precise control and faster troubleshooting.

In essence, an IO-Link device—such as an intelligent sensor, actuator or mechatronic component—makes use of existing connection technology and elevates it by adding smart communication capabilities that make automation systems more efficient and responsive. IO-Link is touted as being as easy to use as the traditional 3-wire setup, only more powerful and versatile. A typical IO-Link system consists of an IO-Link master, IO-Link devices and the cables that connect IO-Link devices to the IO-Link master’s ports.

Why is IO-Link Important?

A commonly held misconception about IO-Link is that it can replace EtherNet/IP or Profinet. Rather, it is a complementary networking technology that can enable better overall performance and reliability.

IO-Link was designed as a simple, universal or open standard, and is intended to simplify the smart sensor and intelligent device connectivity on the factory floor. No special cabling or connectors are needed. It requires only standard M12/M8/M5 cables.

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A useful analogy, as described in a blog on sensor and automation specialist Balluff’s website, is to think of IO-Link as a USB for industrial automation. This characterization is useful in proffering IO-Link’s role in enabling one of the most important operational objectives: to ensure equipment availability. 

Five Considerations That Make IO-Link Essential in Machine Builds 

Communicate with equipment at the lowest level. IO-Link provides two-way communication between sensors and actuators and low-level control systems. IO-Link smart devices can provide data on temperature, stress levels, error codes, configuration and parameter issues.  

Replace analog signals with digital signals that enable real-time monitoring. IO-Link communication provides detailed diagnostic information based on raw sensor values thereby enabling predictive maintenance and quicker troubleshooting. This results in uptime and reliability gains and increasing equipment life span. 

Increase compatibility with standard equipment. IO-Link uses standard unshielded 3-wire cables, which simplifies wiring and reduces installation costs. Since there is no need for special cables, connectors or complex fieldbus networks, installation can be cost-effective and easier to deploy.

READ MORE: Are Smart Sensors Needed in Your Industrial Machines?

Ensure better device management and better data quality. Devices can be configured remotely, which streamlines setup and adjustment processes.  

Offer a high degree of scalability and flexibility. Companies of all sizes can benefit, as IO-Link enables a modular approach to system design and fosters scalability. New sensors or actuators can be added to the system without significant changes to the overall architecture, which provides flexibility for future expansions. 

Helping Manufacturers Futureproof Processes

Designed to accommodate future technological advancements, IO-Link offers advanced communication capabilities, along with ease of integration, improved diagnostics and remote management capabilities. With standardized interfaces, more data can be collected and made available for optimizing industrial processes.

About the Author

Rehana Begg | Editor-in-Chief, Machine Design

As Machine Design’s content lead, Rehana Begg is tasked with elevating the voice of the design and multi-disciplinary engineer in the face of digital transformation and engineering innovation. Begg has more than 24 years of editorial experience and has spent the past decade in the trenches of industrial manufacturing, focusing on new technologies, manufacturing innovation and business. Her B2B career has taken her from corporate boardrooms to plant floors and underground mining stopes, covering everything from automation & IIoT, robotics, mechanical design and additive manufacturing to plant operations, maintenance, reliability and continuous improvement. Begg holds an MBA, a Master of Journalism degree, and a BA (Hons.) in Political Science. She is committed to lifelong learning and feeds her passion for innovation in publishing, transparent science and clear communication by attending relevant conferences and seminars/workshops. 

Follow Rehana Begg via the following social media handles:

X: @rehanabegg

LinkedIn: @rehanabegg and @MachineDesign

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