This electronic frequency scanner is used to connect a controller (such as a Block Signal or Dual-Head Block Signal) with a receiver (such as Distant Signals, Switch Motors, and Receiver Boxes). To initiate connection, right-click on a controller. Next, right-click on a receiver you want to pair the Controller to. If the pairing is successful you will receive a message saying so. It can also be used to clear an existing pairing by right-clicking on either the controller or the receiver.