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Esphome M30 Modbus Register 231: m30 2 energy sum

Technical documentation for Modbus register 231 on Esphome M30. Data type: U WORD. Includes Python and YAML configuration examples.

January 16, 2026 3 read

Technical Definition

The register m30 2 energy sum at address 231 is used to monitor m30 2 energy sum on the Esphome M30.

  • Protocol: Modbus RTU
  • Data Type: U WORD
  • Unit: kWh
  • Access: Read Only

How to Read (Python pymodbus)

Use this code snippet to read this specific value via RS485:

from pymodbus.client.sync import ModbusSerialClient

client = ModbusSerialClient(method='rtu', port='/dev/ttyUSB0', baudrate=9600)
client.connect()

# Read m30_2_energy_sum (Address: 231)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=231, count=2, unit=1)

if not result.isError():
    print(f"Raw Value: {result.registers}")
else:
    print("Error reading register")

client.close()

Integration (Home Assistant)

Paste this into your configuration.yaml:

- platform: modbus_controller
  name: "m30_2_energy_sum"
  address: 231
  value_type: U_WORD
  unit_of_measurement: "kWh"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Esphome M30]

    PLC -- "A+ (D+)" --> Device
    PLC -- "B- (D-)" --> Device
    PLC -- GND --> Device


💡 Engineer's Insight

Analysis: Total accumulated energy consumption (kWh) from multiple channels.

Troubleshooting: Zero value may indicate no overall usage, sensor failure, or communication error.