I’m just about to switch from FHEM to openhab2.
To be able to play around with the rules, I would like to set up a DUMMY switch, because then I can switch over the UI and over rules.
In FHEM that would be “define xyz DUMMY”.
Is this also possible in openHAB2?
To add a bit more, you just define an Item without giving any link to a binding/channel that would connect it with real device.
“Virtual” Items are not considered anything special in OpenHAB. It’s a good way to develop rules.
To see your Item on a UI, you’ll need to put it in a Sitemap in the usual way.
I’m not sure if it is exactly so. I have several items, which are not connected to physical device. They are updated by MQTT Event binding. In this case regardless of which topic I publish the value - stateSubscribeTopic or commandSubscribeTopic Item state is not updated in UI, but Event log shows, that Item is changed.
I had to add MQTT2 binding, and define there a dummy thing with dummy channel, which was connected to this item, to make UI update work. Maybe it is a specifics of MQTT binding.
Something wrong with your setup. Nothing to go on, no logs, no config, not even the UI in use.
Open a new thread and give us specific information related to your setup