Han S3 Modbus Register 29: Dev Import L2

Technical Definition

The register dev Import L2 at address 29 is used to monitor dev import l2 on the Han S3.

• Protocol: Modbus RTU
• Data Type: U DWORD
• 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 dev Import L2 (Address: 29)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=29, 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: "dev Import L2"
  address: 29
  value_type: U_DWORD
  unit_of_measurement: "kWh"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Han S3]

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

💡 Engineer's Insight

Analysis: Energy Import L2. Cumulative energy consumed from the grid on Line 2. Units: kWh.

Troubleshooting: Zero reading suggests no L2 consumption or meter fault. Check L2 power, loads, and meter configuration.