'No. Only when there is a state change. We said that.'

Yes you did Ioannis, I'm just trying to understand the mechanism here.

'You should care only for your logic state. And maybe your voltage levels not to fry your module.'

The data sheet does say [High impedance inputs, LVCMOS/LVTTL compatible, 5V tolerant] would you say I could leave 5v on the Input pin to transmitter and switch to 0v/ground to cause a Tx safely? There are two module versions below, should I go for number 2 to be safe? Or is there a low voltage 12f683 that you know of, or is 5v fine?

1/ Part Numbering 2.4 -3.6V Version

2/Part Numbering 3.6 -15V Version