# Fronius

> Supported devices: Fronius Primo GEN24 Plus, Symo GEN24 Plus and Symo Hybrid

Source: https://voltmasters.io/en/docs/device-integrations/battery-systems/fronius/

Our EMS supports the hybrid inverters from **Fronius** with a Fronius storage system, over SunSpec **Modbus TCP**. One inverter carries both the PV strings and the battery, so our EMS reads and steers it over a single connection and shows the battery and the PV strings as two linked child devices.

### Supported devices

-   **Primo GEN24 Plus**: 3.0, 3.6, 4.0, 4.6, 5.0 and 6.0 Plus
-   **Symo GEN24 Plus**: 3.0, 4.0, 5.0, 6.0, 8.0 and 10.0 Plus
-   **Symo Hybrid**: 3.0-3-S, 4.0-3-S and 5.0-3-S

Only the Plus variants of the GEN24 take a storage system. A GEN24 without Plus, and other Fronius inverters without a battery, are added as a [Fronius PV inverter](https://voltmasters.io/en/docs/device-integrations/pv-inverters/fronius/).

> **Note**
>
> Fronius hybrid support is available from EMS controller version **0.0.336**.

### EMS functionality

With the current integration, our EMS enables:

-   Monitoring of the state of charge, the battery power, the PV production and the AC power of the inverter
-   Smart charging and discharging control, including charging from the grid while the EMS is steering
-   PV curtailment through the output limit of the inverter
-   Reactive power control
-   Use in the control algorithms of the EMS, such as self-consumption optimization and peak shaving
-   Incidents for an inverter fault, an inverter alarm and a battery that is not connected

Additional functionality may be added over time as integration capabilities evolve.

> **Note**
>
> **Control is handed back**
> 
> The EMS only takes over the battery, the output limit and the reactive power while it is actually steering the inverter. When it stops, it releases all three and restores the grid charging setting it found, so the inverter continues on its own energy management instead of staying frozen at the last setpoint.

## Setup

1. **Enable Modbus TCP on the inverter**
   
   Connect the inverter to the same network as the Voltmasters Controller and give it a fixed IP address. In the settings of the inverter, enable **Modbus TCP** (SunSpec) and allow **inverter control via Modbus**. Without that control permission the inverter refuses the battery setpoints and the EMS raises an incident.
   
   > **Note**
   >
   > Follow the Fronius manual of your inverter for the exact menu.
2. **Add the inverter in the platform**
   
   Add a device of category **Battery/PCS**, brand **Fronius** and the model of the inverter. It is added as a **Hybrid inverter (BMS and PV)**. The form prefills **Slave ID** `1` and the **Rated power** from the model designation; fill in the IP address and the port (`502` by default).
3. **Create the child devices**
   
   Once the connection works, the wizard discovers the devices behind the inverter and proposes two child devices: **Fronius hybrid storage** (mandatory) and **Fronius hybrid strings**. Keep both and fill in their parameters:
   
   -   **Capacity** on the battery: the inverter does not report the size of the storage system, so the EMS relies on the configured value.
   -   **Minimum SoC** on the battery.
   -   **Production capacity** on the PV strings. Without it the EMS cannot size the PV production and raises a warning.

> **Warning**
>
> **Minimum reserve of the inverter**
> 
> The inverter keeps a minimum reserve of its own, which also serves as its backup power reserve. The EMS does not change it. When that reserve sits above the **Minimum SoC** configured on the battery, the EMS cannot use the band between the two and raises a warning. Compare both values when you commission the site.