problems

I have a ABB ip interface and only some esylux sensors. When i connect with ets6 I can find the interface and download it into ets6. After that I tried to add the sensors to the rooms. But when i download it and put the magnet on the sensor, ets6 finds the sensor but is unable to download all. it get the message that it has an adres but the rest is not able to download. After i try it again there is no possible connection to that adres. What am i doing wrong.