This example is how to pre-select and audio source to a port output, then using the IFB function the source is dimmed or cut when a panel talks to the port output. In this example the Audio panel has a key to pre select a programme input to the studio floor loudspeaker output (LSTB). When the Audio panel talks to the LSTB the selected Prog feed is dimmed by 6dB.
First create an IFB with LSTB as the IFB destination, Prog as the source. The -6dB attenuation should give a 50% reduction when the IFB is actioned.
Next in the Routes menu create an IFB route with Prog as the source, LSTB as the destination.
In the Control menu assign the above route to a control.
On the panel assign the control to a talk key.
Final step, on the panel, assign a talk key to the LSTB IFB