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Esp32 Main Meter Modbus Register 72: Sdm630 import wh since last reset

Technical documentation for Modbus register 72 on Esp32 Main Meter. Data type: FP32. Includes Python and YAML configuration examples.

January 16, 2026 1 min read

Technical Definition

The register sdm630 import wh since last reset at address 72 is used to monitor sdm630 import wh since last reset on the Esp32 Main Meter.

  • Protocol: Modbus RTU
  • Data Type: FP32
  • 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 sdm630_import_wh_since_last_reset (Address: 72)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=72, 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: "sdm630_import_wh_since_last_reset"
  address: 72
  value_type: FP32
  unit_of_measurement: "kWh"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Esp32 Main Meter]

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


💡 Engineer's Insight

Analysis: Total energy imported since last reset (Wh). Represents cumulative consumption.

Troubleshooting: Zero if no energy imported or reset occurred. Check for active loads and meter status.