Han S3 Modbus Register 122: Dev Active Power Export

Technical Definition

The register dev Active Power Export at address 122 is used to monitor dev active power export on the Han S3.

• Protocol: Modbus RTU
• Data Type: U DWORD
• Unit: W
• 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 Active Power Export (Address: 122)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=122, 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 Active Power Export"
  address: 122
  value_type: U_DWORD
  unit_of_measurement: "W"

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: Total active power supplied by the system to the grid. Units: kW. Positive value indicates net export.

Troubleshooting: Zero if system is off or consuming more than generating. Check overall system load and generation.