Esp32 Main Meter Modbus Register 4: Sdm630 phase 3 line to neutral volts

Technical Definition

The register sdm630 phase 3 line to neutral volts at address 4 is used to monitor sdm630 phase 3 line to neutral volts on the Esp32 Main Meter.

• Protocol: Modbus RTU
• Data Type: FP32
• 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 sdm630_phase_3_line_to_neutral_volts (Address: 4)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=4, 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: "sdm630_phase_3_line_to_neutral_volts"
  address: 4
  value_type: FP32
  unit_of_measurement: "V"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

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

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

💡 Engineer's Insight

Analysis: Phase 3 Line-to-Neutral Voltage (Volts). Measures RMS voltage between Phase 3 and Neutral.

Troubleshooting: Inspect Phase 3 connections, neutral integrity, or consider sensor calibration/failure if the voltage is abnormal.