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Solis 4G Modbus Register 3004: ActualPower

Technical documentation for Modbus register 3004 on Solis 4G. Data type: U DWORD. Includes Python and YAML configuration examples.

January 16, 2026 3 read

Technical Definition

The register ActualPower at address 3004 is used to monitor actualpower on the Solis 4G.

  • 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 ActualPower (Address: 3004)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=3004, 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: "ActualPower"
  address: 3004
  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[Solis 4G]

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


💡 Engineer's Insight

Analysis: Actual AC power output in Watts (W). Real-time power delivered by the inverter to the grid or load.

Troubleshooting: Zero value means no AC power output. Investigate grid connection, inverter status, or system load.