Hi @AELhammoudi,
Are you referring to Serial over TCP communication plugin ?
If so, it is supported by FreeMASTER Lite but has experimental status:

I just noticed that the connection string generated by the FreeMASTER tool when exporting service configuration has a wrong format (we will address this issue).
Could you check if your connection string is using the following format:
TCPCOM;{HOST_NAME};port={PORT_NUMBER};timeout={TIMEOUT_IN_MS}
example:
{
...
"connections": [
{
"name": "preset",
"description": "Default connection",
"connection_string": "TCPCOM;127.0.0.1;port=5001;timeout=2000"
}
]
...
}
Let us know if you are still facing issues using this feature so we can improve its stability.
Kind regards,
Iulian