Esp32 Main Meter Modbus Register 22: Sdm630 phase 3 va

Technical Definition

The register sdm630 phase 3 va at address 22 is used to monitor sdm630 phase 3 va on the Esp32 Main Meter.

• Protocol: Modbus RTU
• Data Type: FP32
• Unit: VA
• 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_va (Address: 22)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=22, 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_va"
  address: 22
  value_type: FP32
  unit_of_measurement: "VA"

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: Apparent power for Phase 3 (VA). Measures total power flow, including real and reactive components.

Troubleshooting: Indicates a phase imbalance, a disconnected load, or an issue with the meter's Phase 3 current/voltage sensing.