Unfortunately, the EX-F1 Control can be used only with a single CASIO EX-F1 digital camera. You can't use it with multiple cameras at the same time. Also, you can't open multiple EX-F1 Control instances on the same computer. The Connection wizard from the System menu allows you to use only one camera:
If you want to use another camera, you will need to disconnect the first one and then to connect to the second device.