Isolated M-Bus to TTL Signal Converter for Smart Metering
- Client
- Utilities & energy
- Year
- 2024
- Category
- Internet of Things (IoT)
Existing metering infrastructure is built on M-Bus, but the modern IoT world speaks UART/TTL to microcontrollers and gateways. NELSco designed an industrial signal converter that bridges the two safely and reliably: an EN 13757-2/3 compliant M-Bus input and a selectable 3.3V/5V TTL output, with full protection against surge, ESD, and reverse polarity.
Full galvanic isolation with ≥1.5 kVDC withstand that eliminates ground loops and fully protects downstream electronics; an EN 13757-2/3 compliant M-Bus input and a selectable 3.3V/5V UART/TTL output with 300–9600 bps baud support.
Built-in surge, ESD, reverse-polarity, and EMI protection, plus plug-and-play compatibility with ESP32, STM32, LoRa gateways, GSM modules, and SCADA, with no external conditioning circuits needed.
The Challenge
The M-Bus carries its own voltage and power levels; wiring it straight to a microcontroller risks hardware damage, ground loops, and noise-induced data errors. A standard, isolated interface was needed that works with any gateway or MCU without extra conditioning circuitry and stays stable in industrial environments.
Our Approach
The board was designed with full galvanic isolation (≥1.5 kVDC withstand) between the M-Bus and the TTL side, eliminating ground loops and fully protecting downstream electronics. The physical layer was implemented to EN 13757-2/3, a selectable 3.3V/5V UART/TTL output with 300–9600 bps baud support (the full M-Bus standard range) was provided, and surge, ESD, reverse-polarity, and EMI protection were built in on-board.
The Result
The finished converter is plug-and-play with ESP32, STM32, LoRa gateways, GSM modules, and SCADA systems, with no external conditioning circuits required. It bridges legacy metering infrastructure with modern IoT data-acquisition systems safely and reliably.
Results
- Smart reading of water, gas, and electricity meters in IoT deployments
- Full downstream-electronics protection via ≥1.5 kVDC galvanic isolation
- Safely bridges legacy metering infrastructure with modern data-acquisition systems
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