Esp32 S3 Pv18 Usb Modbus Register 15205: PV Charger Voltage

Technical Definition

The register PV Charger Voltage at address 15205 is used to monitor pv charger voltage on the Esp32 S3 Pv18 Usb.

• Protocol: Modbus RTU
• Data Type: INT16
• 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 PV Charger Voltage (Address: 15205)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=15205, 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: "PV Charger Voltage"
  address: 15205
  value_type: INT16
  unit_of_measurement: "V"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Esp32 S3 Pv18 Usb]

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

💡 Engineer's Insight

Analysis: Measures the output voltage from the PV charger to the load or battery. Units: Volts (V).

Troubleshooting: Zero voltage may indicate no solar input, a faulty charger output stage, or an open circuit in the connected system.