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Modbus Ozone2 Modbus Register 2: Device humidity

Technical documentation for Modbus register 2 on Modbus Ozone2. Data type: FP32 R. Includes Python and YAML configuration examples.

January 16, 2026 3 read

Technical Definition

The register device humidity at address 2 is used to monitor device humidity on the Modbus Ozone2.

  • Protocol: Modbus RTU
  • Data Type: FP32 R
  • 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 device humidity (Address: 2)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=2, 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 humidity"
  address: 2
  value_type: FP32_R
  unit_of_measurement: "%"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Modbus Ozone2]

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


💡 Engineer's Insight

Analysis: Humidity reading from the Ozone2 device in percentage.

Troubleshooting: Sensor failure, condensation on sensor, or data communication issue. Check sensor environment and connection.