Hisense H-Link Protocol

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# Project description 

This project has the aim to reversee engineer the H-Link Protocol used in Hisense Therma units in order to gain direct control of the machines and not relying on Hisense cloud platform. An Home Assistant custom component will be developed too.

## System description

Hisense Hi-Therma lineup is composed of both monoblock and split heatpumps. The unit I have under test is a 8kW monoblock type AHZ-080HCDS1.

![](https://climaconvenienza.it/cdn/shop/files/immagine-1-pompa-di-calore-reversibile-monoblocco-hisense-hi-terma-ahz-080hcds1-r-32-wi-fi-optional-con-comando-incluso_grande.jpg?v=1750325295)

## Communication interfaces

There are 2 HBS interfaces available. One is used with the communication with the master controller ( HSXM-FE01 ) and the other one is used for the communication between outdoor/indoor unit (in my case they are both outdoor) and remote control with the auxilliary Hi-mit II remote controller (HCCS-H64H2C1M). Both can be found at CN1 of PCB1 and they are routed differently between the monoblock/split units. Pin 3,4 are the ones used for the master controller and are labeled as A,B on the terminal block TB4 present on PCB4. Pin 1,2 of CN1 are reserved for the communication with indoor unit / remote interface and are available on TB4 in split units. These pin on the monoblock unit are wired to PCB6 and are also available on the terminal block on PCB7.

![](clipboard-202508020131-gnawr.png)

## Disclaimer

All information provided in this project is based solely on independent research and reverse engineering performed for educational and interoperability purposes.

No proprietary code, confidential documentation, or copyrighted material from Hisense or any third party has been used.

This project is not affiliated with, endorsed by, or sponsored by Hisense.

No copyright infringement is intended.