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Solis Modbus Inv Modbus Register 3004: AC output power

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

January 16, 2026 1 min read

Technical Definition

The register AC output power at address 3004 is used to monitor ac output power on the Solis Modbus Inv.

  • 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 AC output power (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: "AC output power"
  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 Modbus Inv]

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


💡 Engineer's Insight

Analysis: The real-time AC power output of the inverter. Units: Watts (W).

Troubleshooting: Zero implies no load or inverter fault. Check grid connection, loads, and inverter status.