Problems with KNX

I have installed Openhabian on Raspberry PI 2, and I have installed the KNX-binding.
I have av IP 730 Gateway to connect to my KNX-bus, and I have installed KNXD on the Raspberry PI from Openhabian.

When I start Openhab 2 I get connected to the KNX-bus:
2017-08-17 17:48:53.849 [INFO ] [nx.internal.connection.KNXConnection] - Established connection to KNX bus on 224.0.23.12:6720 in mode ROUTER.

I have defined just one Item, witch is of type Switch with an adress of 1/0/2, and I can see in the log, that the Openhab is reading changes in state when I toggle the physical switch in my home:
2017-08-17 17:50:47.387 [ItemCommandEvent ] - Item ‘Lampe’ received command OFF

2017-08-17 17:50:47.401 [ItemStateChangedEvent ] - Lampe changed from NULL to OFF

2017-08-17 17:50:55.537 [ItemCommandEvent ] - Item ‘Lampe’ received command ON

2017-08-17 17:50:55.542 [ItemStateChangedEvent ] - Lampe changed from OFF to ON

When I change the switch in the Basic UI it seems ok:
2017-08-17 19:39:23.511 [ItemCommandEvent ] - Item ‘Lampe’ received command ON

2017-08-17 19:39:23.518 [ItemStateChangedEvent ] - Lampe changed from OFF to ON

2017-08-17 19:39:25.355 [ItemCommandEvent ] - Item ‘Lampe’ received command OFF

2017-08-17 19:39:25.368 [ItemStateChangedEvent ] - Lampe changed from ON to OFF

But the problem is that nothing is happening to the lamp in real life when I change the switch in the Basic UI…

Anyone have a clue why Openhab reads the changes on the KNX-bus, but does not write changes to the bus?

You need to define 2 Group Addresses for your Switch item.
One for the Status (you have that already) and one for the On/Off command.
http://docs.openhab.org/addons/bindings/knx1/readme.html#items-configuration