Fraunhofer Dresden: High-Speed Real-Time Optical Data Link for Industry

Even in environments where wireless communication reaches its limits, it operates reliably and with virtually no delay. As a result, Li-Fi Grathus® opens up new possibilities for flexible, reliable, and proven real-time industrial communication.

In modern industrial facilities, machines, sensors, and control systems must communicate with each other ever more quickly and reliably. Traditional cable connections are often inflexible, while wireless solutions can be prone to interference. This is where Li-Fi Grathus®, developed by the Fraunhofer Institute for Photonic Microsystems IPMS in Dresden, comes in: The technology uses light for data transmission (“Li-Fi” stands for Light Fidelity) and thus enables a wireless connection without radio waves. With data rates of 1 Gbit/s or more and a range of up to 10 meters, the system is suitable for many industrial applications. A key advantage is the extremely short, predictable delay (deterministic latency) of less than 100 nanoseconds. This means that data is transmitted practically in real time, which is particularly important for robotics and precise machine control.

High-speed, reliable, and interference-free

Unlike Wi-Fi or other wireless technologies, Li-Fi Grathus® operates using light signals. This offers a decisive advantage: The transmission is immune to electromagnetic interference (EMI), which frequently occurs in industrial environments. Additionally, the system can transmit and receive simultaneously (full-duplex), ensuring no time is lost. The technology can be seamlessly integrated into existing systems and networks without major modifications and supports common industrial standards such as Profinet, EtherCAT, EtherCAT G, and SERCOS III, as well as the new Time Sensitive Networking (TSN). In addition to Ethernet/Gigabit Ethernet, USB 3.0/3.1 and customer-specific interfaces are available. An additional side channel with 1 Mbit/s supports management, diagnostic, and safety signals.

Easy handling in industrial applications

In addition to performance, ease of use plays a particularly important role in practice. Li-Fi Grathus® stands out in this regard with:

• Simple installation: Compared to complex optical data transmission systems such as free-space systems, which require time-consuming alignment or expensive optical systems (e.g., beam steering or adaptive optics), Grathus® can be installed and operated flexibly without any adjustment.
• Innovative, patented multi-path lens: It enables higher transmission power and simple manual alignment.
• Eye-safe operation: Laser Class 1 ensures safe use.
• Robust design: Thermally stable and compact plug-and-play design with a metal housing protects the technology in everyday industrial use
• High flexibility: Enables versatile use in a wide range of applications.

Wide range of applications in industrial automation

Thanks to its proven, predictable real-time communication between control, sensor, and actuator systems, Li-Fi Grathus® is ideal wherever fast and reliable wireless data transmission is required. Typical applications include:

• industrial automation
• robotics
• Motion control (precise motion control of machines)
• Retrofitting of existing systems
• Backhaul and backbone connections for Wi-Fi and cellular access points
• Logistics systems, e.g., shelving and storage systems
• Large rotating machines
• High-bandwidth channels for uploading and downloading sensor data, e.g., in automated guided vehicles (AGVs)

Especially in flexible production environments where machines are frequently reconfigured, wireless connectivity offers significant advantages without compromising deterministic performance. Additionally, it enables reliable operation in metallic environments where radio technologies reach their limits and failures are a risk.