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Heatpump Modbus Register 270: Entity prefix t T4 FRESH C

Technical documentation for Modbus register 270 on heatpump. Data type: U WORD. Includes Python and YAML configuration examples.

January 16, 2026 3 read

Technical Definition

The register entity prefix t T4 FRESH C at address 270 is used to monitor entity prefix t t4 fresh c on the heatpump.

  • Protocol: Modbus RTU
  • Data Type: U WORD
  • Unit: hr
  • 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 entity_prefix t_T4 FRESH_C (Address: 270)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=270, 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: "entity_prefix t_T4 FRESH_C"
  address: 270
  value_type: U_WORD
  unit_of_measurement: "hr"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[heatpump]

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


💡 Engineer's Insight

Analysis: Temperature setpoint for FRESH air cooling in a specific thermal condition (T4). Units are typically degrees Celsius (°C).

Troubleshooting: Zero might indicate the cooling function is disabled, sensor failure, or an ambient Temperature above operational limits.