New install on a RPi4 downloaded from Ubuntu OpenHAB Appliance.
I have the Z-Wave Binding installed.
Under Configuration > Things > Z-Wave Serial Controller it needs a Serial Port.
I’m not sure what to enter and how to find which port it is on the RPi4.
Currently under Things it displays:
Z-Wave Serial Controller OFFLINE - BRIDGE_OFFLINE
Z-Wave Serial Controller
zwave:serial_zstick:f7aa316f
Welcome
Not sure why you would want that. The official recommended image is openHABian which is based off the much more standard Raspbian / RaspiOS image.
Since it is an Appliance, I assume there is some UI enumerating devices? Yuo would better ask that on that appliance support foum.
Ah ok, I’ll install openHABian then.
I stumbled across the Ubuntu appliance… I have no idea what I’m doing 
This is part of the official documentation. Be sure to read about the openHAB concepts too
Remember:The stick has some issues with the USB Ports of the PI 4, it requires an USB 2 hub between the stick and the PI. Any cheap one will work.
Ugh, and I just bought a Pi4 for this.
Mmmmm, maybe I’ll just try it on a Pi3 first, I have 4 running…
I understand they fixed this in the newer Aeotec sticks. The older ones would not work properly in USB3 ports without the hub trick.
Have a look here. If your stick is one of the older ones, the prob is unrelated to whatever operating system. Go get a powered USB Hub. I’d expect the controller not to be shown offline anymore.
If you don’t define a special name/alias for the port, openHAB will find the right one for you normally.
EDIT: To everyone knowing about Aeoctec Gen 5 struggling on a raspi4 port: just do a search for “aeotec v1.” and Alex’s (aka user Celaneo1) post will show up.
Thank you everyone, I’m all sorted now.
I installed openHABian on an RPi3 and it picked up the Z stick immediately and I was able to get my lights setup.
I checked the Aeotec website and my new Z stick is an older model, that sucks.
Moving on… learning more about openHAB.
If you have a powered USB2 hub you can still use the stick with the Pi4.
Noted, but I have a spare Pi3 which does not require an additional powered USB hub
Now I can use the Pi4 for something else, just have not decided what yet.
You do not need a powered hub. I run the stick non a passive hub with a PI4 without issues.
Nobody has mentioned that the RPi 4 has two USB 2.0 ports next to the blue USB 3.0 ports. Might not work for you, but my old stick worked right away as soon as I switched it to the black USB 2.0 ports on the RPi 4.
I just modded my older stick with a resistor like this guide and it works great without the extra hub needed Aeotec Z-Stick Gen5 Raspberry Pi4 Mod - olausson.de
Thanks for this! I would have done this, but I already spent the $5 on amazon and got the dumb hub. For what it’s worth, moving the stick to the 2.0 ports only worked breifly.
As I just explained in another thread, the resistor mod is the proper solution that actually fixes the problem: