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Esp32 Rs232 Modbus Register 303: Name Total PV Charging Power

Technical documentation for Modbus register 303 on Esp32 Rs232. Data type: U WORD. Includes Python and YAML configuration examples.

January 16, 2026 3 read

Technical Definition

The register name Total PV Charging Power at address 303 is used to monitor name total pv charging power on the Esp32 Rs232.

  • Protocol: Modbus RTU
  • Data Type: U WORD
  • 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 name Total PV Charging Power (Address: 303)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=303, 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 Total PV Charging Power"
  address: 303
  value_type: U_WORD
  unit_of_measurement: "W"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Esp32 Rs232]

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


💡 Engineer's Insight

Analysis: Total power generated by the solar panels (PV). Units: Watts (W).

Troubleshooting: Check PV input, inverter status, and wiring connections. May indicate no sun or system fault.