# Changing the ID of a Modbus RTU server

Each server is identified by a server ID which is unique in the scope of the client. In the device tree, servers are sorted by their server IDs .

1. Open the device view.
2. In the device tree, double-click the server you want to delete a data item from.
3. In the combo box Server ID, enter a unique server ID in the range of 1 to 247.
4. Press Enter.

5. ## NOTICE

   If you entered an invalid server ID (e. g. the number is out of range), the server ID will be automatically reset to the last valid server ID.