Modbus RTU Energy Meter Monitoring

How it works

This Coreflux LoT template reads an industrial energy meter over a Modbus Serial Route, scales the registers into engineering values, and publishes them to MQTT topics. A separate LoT Action watches active power events and publishes an alarm when the configured threshold is exceeded.

Key features

• Modbus RTU polling: Reads holding registers from a serial energy meter.
• MQTT publishing: Maps voltage, current, power, frequency, PF, and energy counters to topics.
• Threshold alarm: Raises an alert when active power goes above 3000 W.
• Wildcard monitoring: Uses energy/+/+/active_power for multi-meter fleets.

What this template does

• Polls MeterReading every 1 second.
• Decodes and scales Modbus values into V, A, W, VA, var, Hz, PF, and kWh.
• Publishes meter data under energy/meter/01/... topics.
• Publishes alerts/active_power status per meter and zone.

Prerequisites

• A Modbus RTU energy meter with documented register map.
• Serial access to the RS485 device path.
• Correct slave ID, baud rate, parity, data bits, and stop bits.