Heatpump Modbus Register 178: Total COP in DHW mode for master unit

Technical Definition

The register Total COP in DHW mode for master unit at address 178 is used to monitor total cop in dhw mode for master unit on the heatpump.

• Protocol: Modbus RTU
• Data Type: INT16
• Unit: COP
• 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 Total COP in DHW mode for master unit (Address: 178)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=178, 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: "Total COP in DHW mode for master unit"
  address: 178
  value_type: INT16
  unit_of_measurement: "COP"

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: COP in DHW mode for the master unit. Ratio of DHW output (energy) to energy consumed for heating. Indicates efficiency.

Troubleshooting: Zero or low COP suggests inefficient DHW heating, system faults, or erroneous readings. Check operating conditions and inputs.