The World Exposition 2025 in Osaka, Japan, served as a global stage for technological innovation, but few displays matched the technical complexity and emotional resonance of the nightly multimedia finale, Under the Midnight Rainbow. Staged at the expansive Water Plaza, the production transformed 8,800 square meters of bayfront into a synchronized canvas of light, fire, and water. To manage the immense logistical and technical requirements of a show featuring 300 water fountains, 30 flame effect stations, and a comprehensive suite of laser and audio-visual systems, the production firm ECA2 collaborated with db Show Control & Automation to implement a sophisticated control infrastructure powered by Beckhoff’s PC-based automation technology. This architectural choice ensured that the performance remained flawlessly synchronized for an audience of 2,500 people per night, totaling over two million spectators throughout the six-month duration of the Expo.
The Scale of the Spectacle at Water Plaza
The Water Plaza at Expo 2025 was designed to be the epicenter of the event’s "Designing Future Society for Our Lives" theme, requiring an installation that could withstand the environmental rigors of Osaka Bay while delivering world-class entertainment. The choreography of Under the Midnight Rainbow was centered on an intricate water-jet system. This included 280 stationary jets and eight specialized 3D water jets equipped with dynamic kinematics, allowing for fluid, multi-axis movement. These were complemented by two massive water screens and a cascade screen, which served as the primary projection surfaces for high-definition video mapping.
Beyond the aquatic elements, the show integrated 30 flame effect stations and high-powered fog pumps to add texture and heat to the experience. The sensory environment was completed by a central audio system and a network of lasers. Orchestrating these disparate elements—water, fire, light, and sound—on such a massive scale required a control system capable of deterministic timing and high-speed communication. Aurelien Bouvier, Technical Director at ECA2, emphasized that the primary goal was to maintain an emotional connection with the audience, a task that becomes impossible if the underlying technology suffers from latency or synchronization errors.
Designing a Robust Automation Topology
The backbone of the show’s technical infrastructure was an automation topology built on Beckhoff’s open control platform. At the center of the system, located in the main control room, sat a Beckhoff CX5240 Embedded PC. This unit served as the master show controller, managing the logic and timing for the entire site. The distribution of control across the 8,800-square-meter area was achieved through eleven specialized control racks strategically positioned around the water arena.
The connectivity between these racks and the central controller was facilitated by EtherCAT, an industrial Ethernet system known for its high-speed, real-time performance. This network allowed the controllers to manage nearly 300 frequency converters with microsecond precision. According to Craig Pow Chong, Director of Engineering at db Show Control & Automation, the choice of EtherCAT was vital for achieving the "deterministic" control required for water choreography. Unlike standard networking protocols, which can suffer from jitter, EtherCAT ensures that every command reaches its destination at the exact millisecond required, allowing for the perfectly timed bursts of water and fire that define the show’s aesthetic.
Furthermore, the system utilized standard UDP/TCP Ethernet for high-level communication with the audio-visual (AV) systems. This dual-protocol approach allowed for a seamless bridge between the industrial world of pump and motor control and the creative world of media servers and sound processors.
Environmental Resilience and Safety Integration
Operating a massive outdoor multimedia show in Osaka Bay presents significant meteorological challenges. The region is known for variable wind patterns and high humidity, both of which can disrupt the performance and pose safety risks. A key innovation in the Under the Midnight Rainbow installation was the integration of a software-based environmental monitoring system directly within the TwinCAT automation environment.
A suite of sensors was deployed to continuously monitor temperature, humidity, wind speed, wind direction, and water levels. This data was fed back into the central controller in real-time. If the sensors detected a gust of wind exceeding a specific threshold in the direction of the spectator stands, the TwinCAT system would automatically adjust the frequency converters of the water jets within a fraction of a second. This prevented water from blowing onto the audience or interfering with the flame effects. In more extreme conditions, the system was programmed to deactivate specific flame stations or high-pressure jets to maintain a safe environment.
Functional safety was also a paramount concern, given the proximity of high-voltage equipment, pressurized water, and combustible gas. Rather than relying on traditional, hard-wired safety circuits, which would have required miles of additional cabling, the team utilized Beckhoff’s TwinSAFE technology. By using TwinSAFE EL1918 terminals and communicating via the Fail-Safe over EtherCAT (FSoE) protocol, the engineers integrated safety logic directly into the existing network. This allowed for emergency stop functions and safety-related monitoring to be handled over the same cables as the control data, significantly reducing the complexity and cost of the installation while maintaining the highest safety standards.
The Evolution of Show Playback and Recording
One of the most significant technical breakthroughs in the Osaka project was the development of a proprietary recording and playback platform by db Show Control & Automation. Historically, large-scale shows of this nature required massive server racks to handle the playback of dozens of DMX universes (the standard protocol for lighting and effects). For Expo 2025, db Show Control transitioned to a miniaturized approach using two Beckhoff C6017 Ultra-Compact Industrial PCs.
These palm-sized PCs operated in a master-backup configuration, providing redundant playback of 32 DMX universes. This setup allowed the show to run autonomously, handling time-coded sequences with a level of reliability that matches much larger, more expensive server configurations. Pow Chong noted that this shift represents a "paradigm change" in the industry, moving away from bulky, energy-intensive hardware toward compact, high-efficiency industrial computing.
In addition to playback, the system utilized the TwinCAT Database Server to log every piece of data generated by the sensors and the control system. This provided the technical team with a deep reservoir of diagnostic information, allowing for real-time monitoring of pump health, power consumption, and environmental impact. This data-driven approach ensured that the maintenance team could address potential issues before they resulted in a technical failure.
Performance Analysis and Industry Impact
The success of Under the Midnight Rainbow is reflected in its performance metrics. Over the course of the six-month Expo, the show was performed nightly without a single technical outage. This level of reliability is rare in the high-stakes world of international expositions, where the complexity of the systems often leads to intermittent downtime.
David Birchall, CEO of db Show Control & Automation, attributed this success to the unique convergence of industrial hardware and entertainment-specific protocols. He noted that Beckhoff is currently the only control manufacturer that natively supports a broad spectrum of industry protocols—including DMX, sACN, and QSC integration—while maintaining the ruggedness of industrial-grade hardware.
The implications for the wider entertainment and architectural sectors are significant. The project demonstrates that the gap between "show control" and "industrial automation" is closing. By using tools originally designed for factory floors and high-speed manufacturing, entertainment engineers can create spectacles that are more complex, safer, and more resilient than ever before. The ability to react to environmental changes in real-time, combined with the miniaturization of playback hardware, sets a new benchmark for permanent and semi-permanent outdoor installations.
Future Outlook and Legacy
As Expo 2025 concludes, the technical framework established for Under the Midnight Rainbow is already being adapted for future projects. ECA2 and db Show Control & Automation have confirmed that they are currently developing a follow-up installation of a similar scale, utilizing the same Beckhoff-based automation topology.
The legacy of the Osaka show will likely be defined by its seamless integration of technology and artistry. While the audience was captivated by the "Midnight Rainbow" of water and light, the true innovation lay beneath the surface—in the racks of EtherCAT terminals and the compact PCs that ensured every drop of water and every burst of flame occurred exactly as choreographed. This project serves as a definitive case study in how modern automation technology can be harnessed to deliver flawless, large-scale public entertainment in the most demanding environments on Earth.
