A high-speed, real-time optical data connection for industrial applications

Modern industrial facilities require machines, sensors and control systems to communicate with one another fast and reliably. Traditional wired connections are often inflexible, and wireless solutions are susceptible to interference. Li-Fi Grathus, developed by the Fraunhofer Institute for Photonic Microsystems IPMS, is designed to address this challenge. The technology uses light for data transmission (Li-Fi), providing a wireless connection that does not rely on radio waves. With data rates of 1 Gb/s or more and a range of up to 10 m, the system is suitable for many industrial applications. A key advantage is its extremely short and predictable (deterministic) latency of less than 100 ns, about 10,000 times lower than 5G and Wi-Fi. This allows for truly real-time data transmission, which is crucial for robotics and precise machine control.

Using light signals instead of radio waves gives Li-Fi Grathus a key advantage: immunity to electromagnetic interference (EMI), which is common in industrial environments. The system also supports full-duplex communication, transmitting and receiving simultaneously, which ensures uninterrupted data flow and prevents any time loss. It can be seamlessly integrated into existing systems and networks without major modifications and supports common industrial standards, such as Profinet, EtherCAT, EtherCAT G, SERCOS III and Time Sensitive Networking (TSN). In addition to Ethernet and Gigabit Ethernet, it supports USB 3.0/3.1 and user-specific interfaces. An additional side channel with 1 Mb/s supports management, diagnostics and safety signals.

In addition to performance, ease of use is crucial in practical industrial settings. Li-Fi Grathus is designed to offer easy installation: unlike complex optical systems such as free-space setups, which require time-consuming alignment, or costly solutions like beam steering or adaptive optics, Li-Fi Grathus can be installed and operated flexibly without any adjustments. A patented multi-path lens allows higher transmission power and simple manual alignment.

Its thermally stable, compact, plug-and-play design with metal housing protects the technology in everyday industrial use, and eye safety is ensured through the use of Class 1 laser technology.

With its reliable, real-time communication between control, sensor and actuator systems, Li-Fi Grathus is designed for applications that require fast, wireless data transmission. Typical use cases include industrial automation, robotics, motion control, large rotating machinery, logistics systems and high-bandwidth channels for uploading and downloading sensor data in automated guided vehicles (AGVs), as well as backhaul and backbone connections for Wi-Fi and cellular access points.

Wireless connectivity offers significant advantages, especially in flexible production environments, where machines are frequently reconfigured without compromising deterministic performance. It also ensures reliable operation in metallic environments, which are challenging for traditional radio technologies and can lead to failures.

“Li-Fi Grathus builds on more than 15 years of Li-Fi expertise at Fraunhofer IPMS,” said Dr René Kirrbach, Group Leader for Li-Fi at Fraunhofer IPMS. “Our latest development provides fast, secure, real-time optical wireless communication for industrial applications and is compatible with numerous industrial Ethernet standards. Its robust design makes it ideal for demanding industrial environments.”

Li-Fi Grathus is available as an evaluation kit; a ‘ready-to-use’ set that enables the easy replacement of a wired 1 Gbps Ethernet connection with an optical link via plug-and-play, while also allowing testing of the technology’s basic functions in practice. The kit includes two Grathus modules, two Ethernet cables, a power supply and a user manual.

Image: Li-Fi Grathus from Fraunhofer IPMS. ©Fraunhofer IPMS. Credit: Sebastian Lassak