Each Freewire can be set to transmit or receive. Four Freewires can serve as two send/receive systems, operating on two different Channels. Or all Freewires can be set on the same Channel so that they can operate as one system - a transmitter and three receivers.
The Freewire has eight unique Channel Codes. FreeWire units set to one Channel cannot activate FreeWires set to different Channels. You control the Channel Code to make FreeWire units work together or independently, as required. There are 32 individual Channel/Zone settings at your disposal, and 256 possible lighting combinations!