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Esp32 Srne Asf Example Modbus Register 22: Hardware Version

Technical documentation for Modbus register 22 on Esp32 Srne Asf Example. Data type: U DWORD. Includes Python and YAML configuration examples.

January 16, 2026 1 min read

Technical Definition

The register Hardware Version at address 22 is used to monitor hardware version on the Esp32 Srne Asf Example.

  • Protocol: Modbus RTU
  • Data Type: U DWORD
  • 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 Hardware Version (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: "Hardware Version"
  address: 22
  value_type: U_DWORD
  unit_of_measurement: ""

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Esp32 Srne Asf Example]

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


💡 Engineer's Insight

Analysis: Indicates the hardware revision of the device. Format is typically X.Y.

Troubleshooting: 0 or unexpected value suggests a hardware issue or incorrect reading. Inspect hardware components and connections.