Esp01 Pv18 Modbus Register 25242: Inverter Relay state Earth

Technical Definition

The register Inverter Relay state Earth at address 25242 is used to monitor inverter relay state earth on the Esp01 Pv18.

• Protocol: Modbus RTU
• Data Type: INT16
• Unit:
• 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 Relay state Earth (Address: 25242)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=25242, 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 Relay state Earth"
  address: 25242
  value_type: INT16
  unit_of_measurement: ""

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Esp01 Pv18]

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

💡 Engineer's Insight

Analysis: Indicates the state of the relay responsible for earth/ground connection. Binary status.

Troubleshooting: Zero could mean a fault detected requiring grounding, or a failure in the grounding relay circuit.