Hi
My apologies, I thought we posted about the VMB1TS being up and running in a development version that Cédric is working on.
You can access it by downloading and running this script.
sudo wget http://www.mdar.co.uk/dl/openhab2/update-velbus-jar-dev.sh
sudo sh update-velbus-jar-dev.sh
Just make sure you only have 1 binding running in openHAB2
By accessing the Karaf console and checking the bundle list
openhab-cli console
bundle:list | grep Velbus
I’ve got this binding running on a 2.4 version and a 2.5 
Does that help you?