Geo9 Modbus Register 6171: HeatPump Cold Side return T13

Technical Definition

The register HeatPump Cold Side return T13 at address 6171 is used to monitor heatpump cold side return t13 on the Geo9.

• 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 HeatPump Cold Side return T13 (Address: 6171)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=6171, 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: "HeatPump Cold Side return T13"
  address: 6171
  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[Geo9]

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

💡 Engineer's Insight

Analysis: Return Temperature (T13) of the cold side loop of the heat pump. Units: °C. Typical range: 5-20°C.

Troubleshooting: Incorrect sensor reading, low coolant flow, or external Temperature influence. Check for leaks or pump issues in the cold loop.