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Ctc Ecozenith I250 Modbus Register 632: Heat pump 1: Flow Temperature in

Technical documentation for Modbus register 632 on Ctc Ecozenith I250. Data type: S WORD. Includes Python and YAML configuration examples.

January 16, 2026 3 read

Technical Definition

The register Heat pump 1: Flow Temperature in at address 632 is used to monitor heat pump 1: flow Temperature in on the Ctc Ecozenith I250.

  • Protocol: Modbus RTU
  • Data Type: S WORD
  • Unit: °C
  • 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 Heat pump 1: Flow temperature in (Address: 632)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=632, 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: "Heat pump 1: Flow temperature in"
  address: 632
  value_type: S_WORD
  unit_of_measurement: "°C"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Ctc Ecozenith I250]

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


💡 Engineer's Insight

Analysis: Flow Temperature in. Likely in degrees Celsius (°C). Temperature of the fluid entering the system or a specific component.

Troubleshooting: Zero value could be a sensor fault, no fluid input, or a communication issue. Verify system operation.