Confused by the Souliss Arduino Binding description

Hi there,
I am new here and new to use openHAB. I have tried FHEM before but could not got the structure. openHAB worked from the start with the provided examples and configurations. Now I like to make my own numbering and addressing suitable to my environment. Can some one please help me with a explanation of the Souliss Binding configuration.

As I understand there are 3 parameters for addressing
IP_LAN is the IP address of a gateway / node (Arduino)
USER_INDEX is a unique number of a user interface
NODE_NUMBER is a unique number only used in openHAB for adressing different Souliss nodes
but
NODE_INDEX, I could not figure out what it is standing for

If I have more than one node,
where in the Binding configuration the next node starts?
And are the timings for all nodes or can I use different timings for different nodes?

Thank you in advance