# Huawei SUN2000

Part of the [compatibility overview](/integrations/compatibility), which lists every selectable Mains type.

* Modbus TCP through the **SDongle** (LAN or WLAN). Modbus TCP is off by
  default and has to be enabled with installer access; the steps are below.
* A **Huawei Smart Power Sensor (DTSU666-H)** must be connected to the
  inverter. Without it the station receives no values at all.
* Give the dongle a fixed IP. The dongle serves **one Modbus client at a
  time**; a parallel Home Assistant, evcc or Loxone connection to the same
  inverter blocks the station's reading.
* The station polls every 12 seconds, the interval the inverter tolerates;
  regulation reacts more slowly than with other types. After repeated read
  failures the station retries only every few minutes, so recovery after an
  inverter outage can take up to five minutes.
* Verified with SUN2000 M1 units with and without LUNA2000 battery. Other
  residential SUN2000 generations (L1, M0, M2, MB0) use the same registers
  and are expected to work. With two LUNA2000 units only the first is read.
* Not covered: installations with **EMMA** and commercial systems behind a
  **SmartLogger 3000**.

## Commissioning

Prerequisites: SUN2000 with SDongle, the Smart Power Sensor connected to the
inverter, and **installer access** to the inverter. Modbus TCP on the dongle
is disabled from the factory and can only be switched on with the installer
role.

1. **Station:** under *Configuration → Mains options* set *Mains type* to
   `Huawei` and enter the IP address of the SDongle. Save; the station
   restarts.
2. **Inverter app:** install Huawei's commissioning app (*SUN2000* or
   *FusionSolar*, version 3.2.00.015 or newer; Huawei distributes it through
   its own app gallery, not necessarily through the usual app stores). Connect
   the phone to the inverter's WLAN hotspot and log in as **installer**.
3. **Enable Modbus TCP:** go to *Settings → Communication configuration →
   Dongle parameter settings → Modbus TCP* and select **Enable
   (unrestricted)**. If the *Modbus TCP* entry is missing, the inverter
   firmware is too old; ask the installer to update it first.
4. **Check:** the station's overview shows the grid power; with a LUNA2000
   the battery power and state of charge appear as well. The first values
   can take up to a minute because of the 12-second polling.

If the system was installed by a third party and you do not have the
installer credentials, ask the installer to enable Modbus TCP on port 502
for you; they can do it from their FusionSolar installer portal.