Sensors pull data only when refreshing .items

Hi everybody,

currently I’m using OH2 with my KNX instance. Since yesterdays I am able to read sensor data like the temperature. An example item looks like this:

Number Temperatures_EG_GaesteWC “GaesteWC [%.1f °C]” (EG_GaesteWC, zTemp) {knx="<4/2/9"}

When I edit the .items file and save it the update to this file leads to OH refreshing the values from KNX. Here a short extract from the log:

2018-03-14 19:28:33.913 [INFO ] [el.core.internal.ModelRepositoryImpl] - Refreshing model ‘Home.items’
==> /var/log/openhab2/events.log <==
2018-03-14 19:28:34.102 [.ItemChannelLinkAddedEvent] - Link ‘Sonnenaufgang_Time-astro:sun:home:rise#start’ has been added.
2018-03-14 19:28:34.104 [.ItemChannelLinkAddedEvent] - Link ‘Sonnenuntergang_Time-astro:sun:home:set#start’ has been added.
2018-03-14 19:28:34.110 [.ItemChannelLinkAddedEvent] - Link ‘Remote_Send-exec:command:remote-send:run’ has been added.
2018-03-14 19:28:34.116 [vent.ItemStateChangedEvent] - Sonnenaufgang_Time changed from NULL to 2018-03-14T06:52:00.000+0100
2018-03-14 19:28:34.119 [vent.ItemStateChangedEvent] - Sonnenuntergang_Time changed from NULL to 2018-03-14T18:33:00.000+0100
2018-03-14 19:28:34.123 [.ItemChannelLinkAddedEvent] - Link ‘Remote_Send_Args-exec:command:remote-send:input’ has been added.
2018-03-14 19:28:34.127 [.ItemChannelLinkAddedEvent] - Link ‘Remote_Send_Out-exec:command:remote-send:output’ has been added.
2018-03-14 19:28:34.139 [ome.event.ItemCommandEvent] - Item ‘Temperatures_EG_Wohnzimmer’ received command 23.52
2018-03-14 19:28:34.144 [vent.ItemStateChangedEvent] - Temperatures_EG_Wohnzimmer changed from NULL to 23.52

But from then on nothing more happens. OH doesn’t refresh those temperatures until I edit the .items-file again.

What do I have to do so that these values are being updated regularly? A CRON-rule? If it was a rule do you have an example for that? Which command do I use to “pull” data?

Thanks in advance