First, put your Smart Controller into pairing mode:
To Pair With The Vera3 Smart Controller
Bring the door/window sensor to within six feet of your Vera Smart Controller. Then push the button on the rear of the unit as shown below, and hold for a count of 3.
Now the front of the door/window sensor will flash red, indicating that it is ready to communicate for pairing with your Vera Smart Controller.
On the Vera3:
And in the "Devices" screen of your Dashboard, you will see that your door/window sensor is now part of your smart home system: