Connect Tado Extension Kit to Thermomotor


I would like to setup an Tado extension kit to a Roth termomotor (which is not officially supported by Tado)

The Roth thermomotor is a simple on/off device that expand/shrink when a 24v (1w) signal is on/off.

As far as I can read from the manuals, I have to use the low voltage relay interfaces: A and + in a potential free configuration, and connect those to the thermomotor.

But how do I control the voltage? I only wants to send 24v not 36 :-)

And is the simple on/off supported? Do I have to select a specific configuration, and if so, where can I see what they do to find one that match?

Thank you.

Best regards