===== Modbus Settings =====

To access the Modbus settings, go to the **sidebar** and click on **Network → Modbus**.\\
The configuration options will appear in the **Modbus** settings box.

''🔓 **Modbus functionality is optional** and must be unlocked before use.\\
You can purchase the activation on [[https://grnbms.de|grnbms.de]]. Once activated, the features will be available immediately.''

==== Activated ====

Enable this checkbox to turn on the Modbus server.\\
If disabled, all other fields are ignored.

==== Slave ID ====

Modbus address of this device (used for RTU-style communication).\\
Default is usually ''1''.\\
''⚠️ Must be unique if multiple Modbus devices share the same bus.''
==== Port ====

TCP port used for Modbus communication.\\
Default: ''502''.\\
Only change if your system requires a non-standard port.

==== Protocol ====

Choose between:\\
• **RTU over TCP** – binary Modbus RTU frames inside TCP packets\\
• **TCP** – pure Modbus TCP protocol\\
''💡 Use **RTU over TCP** if your client expects RTU framing.\\
Use **TCP** for standard Modbus TCP clients.''
==== Hardware Port ====

Select the **serial interface** to use for Modbus RTU.\\
Only shown if a serial port is available (e.g. RS485 1).

==== Ethernet ↔ Hardware Bridge ====

Enable this to forward Modbus traffic between Ethernet and the selected serial hardware port.\\
This allows external Modbus clients to talk to devices on the serial line through the BMS.\\
''⚠️ Use with caution – this enables full passthrough between interfaces.''

==== Protocol Documentation ====

{{:grnbmsmk3modbus_v1.pdf|grnbmsmk3modbus_v1.pdf}}