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Esp32 S3 Pv18 Usb Modbus Register 25211: Inverter Grid current

Technical documentation for Modbus register 25211 on Esp32 S3 Pv18 Usb. Data type: INT16. Includes Python and YAML configuration examples.

January 16, 2026 1 min read

Technical Definition

The register Inverter Grid current at address 25211 is used to monitor inverter grid current on the Esp32 S3 Pv18 Usb.

  • Protocol: Modbus RTU
  • Data Type: INT16
  • Unit: A
  • 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 Inverter Grid current (Address: 25211)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=25211, 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: "Inverter Grid current"
  address: 25211
  value_type: INT16
  unit_of_measurement: "A"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Esp32 S3 Pv18 Usb]

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


💡 Engineer's Insight

Analysis: Current drawn from or supplied to the AC grid. Units: Amperes.

Troubleshooting: Zero might mean no grid interaction or device issue. Check grid conditions and inverter export/import.