Hitachi Yutaki ATW-MBS-02
Monitors and controls Hitachi Yutaki air-to-water heat pumps, heating circuits, hot water and pool.
The Hitachi ATW-MBS-02 is a Modbus gateway that links a Yutaki air-to-water heat pump to a building system over RS485 or Ethernet. This Modbus RTU template reads temperatures, water flow, compressor data, operating state and alarms, and lets you switch the unit and change heating, hot water and pool setpoints from ModbusCloud.
- Protocol
- Modbus RTU
- Connection
- RS485, 19200 baud
- Registers
- 115, read and write
- Brand
- Hitachi
- Key readings
- Outdoor temperature · Water inlet and outlet temperature · Hot water temperature · Water flow · Compressor frequency and current · Operation state · Alarm number
- Available commands
- Unit run and mode · Circuit run and water setpoints · Room thermostat setpoint · Hot water setpoint and boost · Pool setpoint · Anti legionella
- Compatible models
- ATW-MBS-02 (7E549924) with YUTAKI S · ATW-MBS-02 with YUTAKI S COMBI · ATW-MBS-02 with YUTAKI S80 · ATW-MBS-02 with YUTAKI M · Hitachi YUTAKI S, S COMBI, S80 and M, line-up 2016 and later
- Last updated
Registers (115)
115 read, 34 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Outdoor Ambient Temperature | °C | Read | |||
| Water Inlet Temperature | °C | Read | |||
| Water Outlet Temperature | °C | Read | |||
| Heat Pump Water Outlet Temperature | °C | Read | |||
| DHW Temperature | °C | Read | |||
| Pool Temperature | °C | Read | |||
| Water Temperature Setpoint | °C | Read | |||
| Water Flow | m³/h | Read | |||
| Water Pump Speed | % | Read | |||
| Compressor Frequency | Hz | Read | |||
| Compressor Current | A | Read | |||
| Unit Power Consumption | kWh | Read | |||
| Unit Capacity | kWh | Read | |||
| Outdoor Average Temperature | °C | Read | |||
| Second Ambient Temperature | °C | Read | |||
| Second Ambient Average Temperature | °C | Read | |||
| Water Outlet Temperature 2 | °C | Read | |||
| Water Outlet Temperature 3 | °C | Read | |||
| Gas Temperature | °C | Read | |||
| Liquid Temperature | °C | Read | |||
| Discharge Gas Temperature | °C | Read | |||
| Evaporation Temperature | °C | Read | |||
| Indoor Expansion Valve Opening | % | Read | |||
| Outdoor Expansion Valve Opening | % | Read | |||
| Mixing Valve Position | Read | ||||
| Capacity Data | Read | ||||
| R134a Discharge Temperature | °C | Read | |||
| R134a Suction Temperature | °C | Read | |||
| R134a Discharge Pressure | MPa | Read | |||
| R134a Suction Pressure | MPa | Read | |||
| R134a Compressor Frequency | Hz | Read | |||
| R134a Expansion Valve 2 Opening | % | Read | |||
| R134a Compressor Current | A | Read | |||
| Operation State | Read | ||||
| Alarm Number | Read | ||||
| H-LINK Communication State | Read | ||||
| System Status 2 | Read | ||||
| System Configuration | Read | ||||
| Cause Of Stoppage | Read | ||||
| Defrosting | Read | ||||
| R134a Retry Code | Read | ||||
| Central Mode | Read | ||||
| Unit Run Status | Read | ||||
| Unit Mode Status | Read | ||||
| Unit Run Command | Read and write | ||||
| Unit Mode Command | Read and write | ||||
| Circuit 1 Run Command | Read and write | ||||
| Circuit 1 Heating OTC Command | Read and write | ||||
| Circuit 1 Cooling OTC Command | Read and write | ||||
| Circuit 1 Heating Water Fix Setpoint | °C | Read and write | |||
| Circuit 1 Cooling Water Fix Setpoint | °C | Read and write | |||
| Circuit 1 Eco Mode Command | Read and write | ||||
| Circuit 1 Heat ECO Offset | Read and write | ||||
| Circuit 1 Cool ECO Offset | Read and write | ||||
| Circuit 1 Modbus Thermostat Enable | Read and write | ||||
| Circuit 1 Thermostat Setpoint | °C | Read and write | |||
| Circuit 1 Room Temperature Input | °C | Read and write | |||
| Circuit 2 Run Command | Read and write | ||||
| Circuit 2 Heating OTC Command | Read and write | ||||
| Circuit 2 Cooling OTC Command | Read and write | ||||
| Circuit 2 Heating Water Fix Setpoint | °C | Read and write | |||
| Circuit 2 Cooling Water Fix Setpoint | °C | Read and write | |||
| Circuit 2 Eco Mode Command | Read and write | ||||
| Circuit 2 Heat ECO Offset | Read and write | ||||
| Circuit 2 Cool ECO Offset | Read and write | ||||
| Circuit 2 Modbus Thermostat Enable | Read and write | ||||
| Circuit 2 Thermostat Setpoint | °C | Read and write | |||
| Circuit 2 Room Temperature Input | °C | Read and write | |||
| DHW Run Command | Read and write | ||||
| DHW Setpoint | °C | Read and write | |||
| DHW Boost Request | Read and write | ||||
| DHW Demand Mode Command | Read and write | ||||
| Pool Run Command | Read and write | ||||
| Pool Setpoint | °C | Read and write | |||
| Anti Legionella Run Command | Read and write | ||||
| Anti Legionella Setpoint | °C | Read and write | |||
| Block Menu 6 Command | Read and write | ||||
| BMS Alarm Command | Read and write | ||||
| Circuit 1 Run Status | Read | ||||
| Circuit 1 Heating OTC Status | Read | ||||
| Circuit 1 Cooling OTC Status | Read | ||||
| Circuit 1 Heating Water Fix Setpoint Status | °C | Read | |||
| Circuit 1 Cooling Water Fix Setpoint Status | °C | Read | |||
| Circuit 1 Eco Mode Status | Read | ||||
| Circuit 1 Heat ECO Offset Status | Read | ||||
| Circuit 1 Cool ECO Offset Status | Read | ||||
| Circuit 1 Thermostat Setpoint Status | °C | Read | |||
| Circuit 1 Room Temperature | °C | Read | |||
| Circuit 1 Wireless Setpoint | °C | Read | |||
| Circuit 1 Wireless Room Temperature | °C | Read | |||
| Circuit 2 Run Status | Read | ||||
| Circuit 2 Heating OTC Status | Read | ||||
| Circuit 2 Cooling OTC Status | Read | ||||
| Circuit 2 Heating Water Fix Setpoint Status | °C | Read | |||
| Circuit 2 Cooling Water Fix Setpoint Status | °C | Read | |||
| Circuit 2 Eco Mode Status | Read | ||||
| Circuit 2 Heat ECO Offset Status | Read | ||||
| Circuit 2 Cool ECO Offset Status | Read | ||||
| Circuit 2 Thermostat Setpoint Status | °C | Read | |||
| Circuit 2 Room Temperature | °C | Read | |||
| Circuit 2 Wireless Setpoint | °C | Read | |||
| Circuit 2 Wireless Room Temperature | °C | Read | |||
| DHW Run Status | Read | ||||
| DHW Setpoint Status | °C | Read | |||
| DHW Boost Status | Read | ||||
| DHW Demand Mode Status | Read | ||||
| Pool Run Status | Read | ||||
| Pool Setpoint Status | °C | Read | |||
| Anti Legionella Run Status | Read | ||||
| Anti Legionella Setpoint Status | °C | Read | |||
| Block Menu 6 Status | Read | ||||
| BMS Alarm Status | Read | ||||
| Unit Model | Read | ||||
| Software PCB | Read | ||||
| Software LCD | Read |
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If a device is not in the library yet, we build the template for free as soon as we have the register data.
Use cases
- Show outdoor, flow and return temperatures of each heat pump on a ModbusCloud dashboard.
- Send an email when the alarm number is not 0 so you can see a fault before the customer calls.
- Compare water inlet and outlet temperature with water flow in the history to check the heat output.
- Raise or lower the hot water setpoint or start a boost remotely from ModbusCloud.
- Track compressor frequency and current over a season to spot short cycling.
- Get an alert when the H-LINK communication state reports no connection with the unit.
Installation
Wire the ATW-MBS-02 to the H-LINK terminals of the Yutaki and give it 230 V power.
Connect RS485 + and - of the gateway to B and A on the ModbusCloud Gateway and set SW1-1 for termination at the end of the bus.
Check address, speed and parity with the Net configuration tool; default is ID 1, 19200 baud, even parity.
In ModbusCloud, add a Modbus device with these settings and import this template.
Check that outdoor temperature and operation state come in, and set central operation to Full on the Yutaki controller before writing.
Things to watch for
The gateway does not answer on RS485. What should I check?
Check ID, speed and parity: 1, 19200 baud and even parity by default. Swap + and - if nothing answers, and check that termination is only on at the ends of the bus. The gateway must be powered before the Yutaki is configured, otherwise it does not see the unit.
All values read 65535 or the H-LINK state says no communication.
The gateway answers but has no data from the heat pump. Check the H-LINK wiring to the Yutaki and that no other Hitachi gateway or central controller is on the same H-LINK. After a power cycle the state shows data initialization for a few minutes.
My writes are accepted but the heat pump changes them back.
Set central operation to Full in the system configuration of the Yutaki controller; in Local mode the controller overrules setpoints and run commands. Write the command registers and read the status registers to see what the unit actually uses.
Why do the registers not match my older Yutaki?
Units from before the 2016 line-up use a different register map on the same gateway. This template covers the 2016 line-up of Yutaki S, S Combi, S80 and M.
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