Esphome Web 51C8D0 Modbus Register 600: Device type-Grid Voltage L3

Technical Definition

The register device type-Grid Voltage L3 at address 600 is used to monitor device type-grid voltage l3 on the Esphome Web 51C8D0.

• 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 device_type-Grid Voltage L3 (Address: 600)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=600, 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: "device_type-Grid Voltage L3"
  address: 600
  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[Esphome Web 51C8D0]

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

💡 Engineer's Insight

Analysis: Grid Voltage L3: Represents the RMS voltage (Volts) of the AC grid on phase 3. Important for balanced three-phase system operation.

Troubleshooting: Zero reading indicates no grid voltage on L3. Check the grid supply, relevant breakers, and L3 connections.