| Device Type | Modbus TCP (Ethernet) | RS485 | Curtailment |
|---|---|---|---|
| Battery Containers | ✅ | ❌ | ✅ |
The Sofar EMS connects to the Volstora battery container using a standard Ethernet (network) cable. The communication runs on the protocol.
[!INFO]
Connection Details
- Protocol: Modbus TCP
- IP Address: You must get this from the Volstora system's network settings.
- Port: The default Modbus port is 502.
- Slave ID / Unit ID: This is the Modbus address of the battery, typically 1.
For correct ethernet wiring, please follow the .
When you add the Volstora battery in the EMS setup, you will be asked for one specific setting:
[!DANGER]
Critical Setting: Battery Size
You must select the correct "Battery Size (ft)" from the dropdown menu.
- 4ft
- 10ft
- 20ft
This setting is critical. The EMS uses it to set the correct power limits for charging and discharging. Choosing the wrong size will lead to incorrect battery control and may prevent the system from working.
If the EMS cannot find the device or isn't showing any data, you can test the network connection manually.
You will need a Modbus testing tool (like Modbus Poll) on a laptop or computer that is on the same network as the Volstora battery.
Open your Modbus tool and set up a new Modbus TCP connection.
Enter the battery's IP Address and the default port 502.
Set the Slave ID (or Unit ID) to match the battery's address (e.g., 1).
Try to read Holding Registers (Function Code 3) at the following addresses:
Register Address: 302
5000 means 50.0%.Register Address: 303
If you can read these values, the network connection is working. If not, double-check your IP address, port, and that the battery is on the same network.
If you see a warning or error message for the Volstora battery in the EMS interface, that message is coming directly from the battery itself. This table shows what the most common codes mean.
| Code Range | Status | Example Messages |
|---|---|---|
| 1 - 49 | Info (Operational) | Container is operational (1)Container is charging (5)Container is discharging (6)Container is balancing (7) |
| 50 - 119 | Warning | General warning reported by container (50)Batteries not responding (58)Battery cell imbalance (65)Cell temperature high (84)String imbalance (95) |
| 120 - 150 | Error (Fault) | E-stop pressed (local or remote) (120)Failure reported by container (127)Dangerously low cell voltage (130)Dangerously high cell temperature (132) |