Esphome Web 10C200 Modbus Register 3020: 43021 Supply fan RPM

Technical Definition

The register 43021 Supply fan RPM at address 3020 is used to monitor 43021 supply fan rpm on the Esphome Web 10C200.

• Protocol: Modbus RTU
• Data Type: U WORD
• Unit: rpm
• 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 43021 Supply fan RPM (Address: 3020)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=3020, 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: "43021 Supply fan RPM"
  address: 3020
  value_type: U_WORD
  unit_of_measurement: "rpm"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Esphome Web 10C200]

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

💡 Engineer's Insight

Analysis: Supply fan speed in revolutions per minute (RPM). Indicates operational speed of the incoming air fan.

Troubleshooting: Zero indicates fan stopped, motor failure, power issue, or control signal loss.