U-Match/RAC Gree

Use cases

• Monitor ambient and outdoor temperatures of Gree AC units on a live cloud dashboard.
• Remotely adjust temperature setpoints and operating modes without visiting the site.
• Create alerts when ambient temperature deviates from the setpoint by more than a defined threshold.
• Schedule on/off commands and sleep mode activation for energy savings during unoccupied hours.
• Track fan speed and swing settings across multiple Gree units in a single building overview.

Installation

1. 1For RAC models, install and wire the XK76 unit controller to the indoor unit before connecting Modbus RTU cabling.
2. 2Connect the Modbus RTU A and B lines from the Gree unit (or XK76 controller) to the RS-485 port on your ModbusCloud gateway (MCG or MLP series).
3. 3Set the baud rate on the gateway to 9600 to match the Gree default Modbus RTU configuration.
4. 4Assign a unique Modbus slave address on each Gree unit and ensure it matches the address configured in the ModbusCloud template.
5. 5Import the Gree U-Match/RAC template in the ModbusCloud platform and map it to the corresponding gateway and slave address.
6. 6Verify communication by checking that ambient temperature and unit status values appear correctly on the dashboard.

Things to watch for

01

Do I need additional hardware to connect RAC units via Modbus RTU?

Yes. RAC models require an XK76 unit controller to expose the Modbus RTU interface. Without this controller, the unit does not have an accessible RS-485 connection.

02

Why are my temperature readings showing incorrect or very large values?

Ambient and outdoor ambient temperature registers use int16 format, while all other registers use uint16. Make sure the data type is set to int16 for temperature registers in your configuration. Incorrect data type settings will produce wrong readings.

03

What baud rate should I use for the Modbus RTU connection?

The default baud rate for Gree U-Match and RAC units is 9600. Ensure both the gateway and the AC unit are set to the same baud rate, parity, and stop bit configuration.

04

Can I control multiple Gree units from one gateway?

Yes. Connect all units on the same RS-485 bus with unique slave addresses. Each unit gets its own template instance in ModbusCloud mapped to its specific address.

Registers (11)

11 read / 9 write

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