GMV (VRF) Gree

Use cases

• Monitor indoor and outdoor ambient temperatures across all VRF indoor units on a live dashboard.
• Adjust setpoint temperatures remotely for individual indoor units without visiting the site.
• Create an alert when an indoor unit power state changes unexpectedly outside of scheduled hours.
• Lock out local temperature and mode adjustments using remote shielding registers during unoccupied periods.
• Log operation mode and fan speed data over time to optimize energy consumption in commercial buildings.
• Push bulk setpoint changes to all indoor units simultaneously during seasonal commissioning.

Installation

1. 1Connect the ModbusCloud gateway (MCG or MLP series) to the Gree GMV AC gateway using a shielded RS-485 cable, wiring A to A and B to B terminals.
2. 2Set the baud rate on both the Gree GMV gateway and the ModbusCloud gateway to 9600, with matching parity and stop bit settings.
3. 3Configure the Modbus RTU slave address on the Gree GMV gateway and ensure it matches the address specified in the ModbusCloud template.
4. 4Import the Gree GMV VRF template from the ModbusCloud template library into your project.
5. 5Verify communication by checking that indoor ambient temperature and power status values appear correctly on the ModbusCloud dashboard.
6. 6Confirm that the template version is 1.0.2 or later to ensure correct temperature setpoint scaling.

Things to watch for

01

Temperature setpoint values seem 10 times too high. What is wrong?

The Gree GMV registers store temperature setpoints multiplied by 10. Ensure you are using template version 1.0.2 or later, which applies the correct scaling factor automatically.

02

I cannot communicate with the Gree GMV system over Modbus RTU. What should I check?

Verify that the RS-485 wiring is correct (A to A, B to B) and that both devices are set to 9600 baud with matching parity and stop bit configuration. Also confirm the correct Modbus slave address is set on the Gree gateway.

03

How do I prevent building occupants from overriding the setpoint or mode locally?

Use the remote shielding registers 441 through 444 to lock out local control of temperature, operation mode, and power. These can be written from the ModbusCloud dashboard or via automation rules.

04

Can I control all indoor units at once instead of one by one?

Yes. The template supports bulk settings that allow you to send a single command to all indoor units simultaneously, for example to change the setpoint or operation mode across the entire system.

Registers (23)

6 read / 21 write

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