I think you are looking in the wrong place.
BEFORE YOU GO TOO FAR
Have you managed to connect to your Velbus network in VelbusLink via the TCP gateway?
This will confirm it is operational.
(As alluded to in my first reply)
WHEN you are happy that VelbusLink is working, Then you can move to getting HA working with the TCP gateway
Follow the instructions here for how to connect over a network " TCP/IP "
Please read ALL of this before continuing
Specifically the part that suggests Velserv, which is the same concept as Velbus-tcp
Example: velserv
- tls: no
- host: your velser IP address - 127.0.0.1 / localhost / 192.168.xxx.xxx
- port: 6000
- password: leave empty
You will need the correct details, identical to those that you used in VelbusLink
EXCEPT The Hostname
Where you can use the full IP address or 127.0.0.1 (to loopback within your NUC)