Classroom Resource: Controlling Multiple EV3's through Daisy Chaining
You have to enable Daisy Chaining for the project on each EV3 Brick. Open a new project and on the Project Properties Page (click on the wrench symbol tab. It is top left tab to the left of your program tabs). Select the Daisy Chaining check box just below the project picture to enable Daisy Chaining. With this enabled, when you drag action, sensor, and flow blocks into your program you will notice a Layer selection box just to the left of the Port selector box. Layer 1 is your first EV3 brick, layer 2 your second and so on down the chain. You can daisy chain up to four EV3 bricks using their USB cables.
Another Daisy Chain feature allows you to use port view to tab through each EV3 sensor layer when connected by USB or Bluetooth. It is very simple to see which motors and sensors are connected to which ports on each of the four EV3 bricks in the Daisy Chain. If you enable Daisy Chain mode in PPP (Project Properties page) and connect to the EV3 daisy chain via Bluetooth or USB, expand the Hardware Page in the bottom right corner (if it isn't already), click on the Port View tab to display information about the sensors and motors connected to the first EV3 Brick in the daisy chain (aka layer 1). You will see four brick layer tabs numbered 1 to 4 just above the Hardware Page. When your EV3 Brick is connected to the computer, you can click through each layer tab with ports automatically identified and interactively populated with sensors values. Daisy Chaining should allow some pretty sophisticated machines to be implemented with relative ease.