I have setup live timing on a server, and am monitoring connections but ATVO never tries to send any data to the server.
Is there any special that needs to be setup localy ?

The livetiming in ATVO is very old and not really supported anymore.

We are in the process of adding new webtiming to replace it. It is more or less finished but not released yet. It is currently not very easy to customize and we are thinking whether we want to add customization or just leave it up to the users to style it with custom css.

Is there any way to get it to start transmitting or is it completely dead?

The old version should still be functional I think, if it is enabled in the settings. I will double check.

Is there any documentation for the live timing? How the server must be set?