EmsTechLabs Logo EmsTechLabs

Device Growatt Spf Modbus Register 1: Name inverter name pv1 voltage

Technical documentation for Modbus register 1 on Device Growatt Spf. Data type: U WORD. Includes Python and YAML configuration examples.

January 16, 2026 3 read

Technical Definition

The register name inverter name pv1 voltage at address 1 is used to monitor name inverter name pv1 voltage on the Device Growatt Spf.

  • Protocol: Modbus RTU
  • Data Type: U WORD
  • Unit: V
  • 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 name_inverter_name_pv1_voltage (Address: 1)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=1, 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: "name_inverter_name_pv1_voltage"
  address: 1
  value_type: U_WORD
  unit_of_measurement: "V"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Device Growatt Spf]

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


💡 Engineer's Insight

Analysis: Voltage from PV1 input on Growatt SPF inverter. Units: Volts.

Troubleshooting: Zero indicates no PV input power, panel issue, or connection problem. Check solar array and wiring.