function activateDeviceBetaFw() {
  var showBetaDevFw = jQuery("#inputShowBetaFw").is(":checked"),
    fieldTestActive = "/etc/config/fieldTestActive";

  if (showBetaDevFw) {
    if (! homematic('CCU.existsFile', {'file': fieldTestActive})) {
      homematic("CCU.createFile", {'file': fieldTestActive});
    }
  } else {
    if (homematic('CCU.existsFile', {'file': fieldTestActive})) {
      homematic("CCU.removeFieldTestActive");
    }
  }
}
Tmporarily introduced with the HmIP-RGBW - this may not be the best place here