The Clear-Com FS II base station / FS II beltpacks can be configured in the configuration editor software to function as a IFB talent system. To setup IFB sources / destinations go to the FS II config editor GUI / IFB tab to program sources, destinations and diming levels.  
One of five FS II Base station inputs can be defined as a source for an IFB. These inputs are the Program Input and the four 4-Wire ports.
All the 4-Wire ports,partyline channels, beltpacks, wireless partylines and stage output can be defined as IFB destinations.
Up to ten IFB key configurations can be set up that group together an IFB source and a number of IFB destinations and set the dimming level for that IFB key configuration.









An IFB talk is a  beltpack with a key set up to talk to the IFB key configuration. Whenever an IFB talk key is pressed the audio from the IFB source to the IFB destinations configured in the IFB key configuration is dimmed by the set amount and the audio from the IFB talk is heard by all the IFB destinations set up in that IFB key configuration.  
The IFB source audio will be dimmed on the IFB destinations for as long as the IFB talk key is active. When the IFB talk key is released the IFB source audio to the destinations will return to normal level.