Hi abacab,
Thanks for the reply.
For example if I press a back-lit button on the keyboard controller it sends a midi message to ACT.
if ACT sends back the same message to the keyboard controller, this button will turn its light on.
The main reason for my quest is that I 've just realized that it is possible to achieve a "Shift lock" in ACT,
by assigning a toggle button to the shift function.
The toggle button sends 127 or 7f when pressed once and 0 when pressed again.
This makes possible to use the shifted functions without having to keep pressing the Shift button.
But this has no value if you don't know if the button is on or off.
Hence the need of the feedback to see the status of the button.
I know it's possible to do this with AZslow's AZ Controller, but it's too complicated.
I'm using currently 3 instances of ACT.
It would take ages to setup and that's definitely not the goal.
Thanks.