Installing on Ubuntu 16.04.03 bare Xorg

[zorgoz]

Hello,

I need to configure an ELO 0700L touch device as the single display for a box PC based solution. Well, I am unable to make it work at all.
I am using Ubuntu 16.04.03 LTS minimal server with Xorg installed but no window manager.
I was following the official documentation (http://support.displaylink.com/knowledgebase/articles/684649-how-to-install-displaylink-software-on-ubuntu) from DisplayLink (for 14.04) and the instructions from here: https://help.ubuntu.com/community/DisplayLink
These two are a little bit different, but than I have found a post here, about systemd related changes.
https://ubuntuforums.org/attachment.php?attachmentid=276426&d=1502971220
After starting the service it looks good:
https://ubuntuforums.org/attachment.php?attachmentid=276427&d=1502971867
Still, even enabled the dlm service is not started on boot, and it is marked as static. Is this normal?
I have also checked that the device is seen by the system:
https://ubuntuforums.org/attachment.php?attachmentid=276428&d=1502971952
I don't want to run XServer on any regular display (as the box PC won't have any), only on the ELO DisplayLink device, with a bare Chromium, nothing else, even no window manager. This is why I have chosen a server installation, and I have installed Xorg.
But xrandr tells me, that it can't open display
I suppose Xorg is not configured. Can somebody give advice how to proceed, how to configure from scratch Xorg for this device only?
Thank you!

[mlukaszek]

xrandr needs X to work, as RandR is an extension of X11 protocol. You need X so modesetting driver uses the device to draw on it.
Service not running at all times is an optimisation to save resources while no device is connected. There are udev rules installed that will start the service when needed.

Cheers,
Michal