The Challenge: Beyond Simple Switching
In 2010, the demand for remote management evolved from simple power cycling to complex telemetry. While working with high-end Swedish Swegon ventilation units, I faced a challenge: providing remote access to deep system parameters that weren’t accessible through standard add-ons at the time.
The Solution: Bridging GSM and Modbus RTU
I developed a solution that allowed my GSM gateway to communicate directly with Swegon’s internal controllers via the Modbus RTU protocol (RS-485).
This was more than just a switch; it was an early IoT bridge:
- Protocol Engineering: I mapped the unit’s internal registers to SMS commands and status reports.
- Deep Integration: Users could not only start the system but also monitor temperatures, airflows, and sensor data remotely.
- Reliability: The system maintained the strict industrial standards required for climate control in commercial buildings.
Professional Integrity and Innovation
This project was implemented during my collaboration with a Swegon dealer. While the specific hardware and proprietary firmware remain with the client, the core achievement was the successful marriage of mobile connectivity and complex industrial protocols.
It proved that even “closed” high-end systems can be made more transparent and manageable through smart, reliable opensource-based approaches.
This project marked my transition from standalone devices to Industrial IoT, where the quality of communication and data integrity is paramount.
Lessons Learned
Implementing Modbus RTU over a GSM link required deep understanding of timing and error correction, as the latency of cellular networks in 2010 could easily break serial communication. This experience became invaluable for future large-scale automation projects.