Not strictly an openHAB2 topic, but as good a place to put this as any.
With the fabulous assistance of people much cleverer than I, I have been able to create Velbus Checksums in JavaScript.
Something that has been baffling me for years and years, because it was holding me back from creating bespoke Velbus packets.
Now that it’s possible, we can (for example) use a TCP node in NodeRed to inject these bespoke packets into our Velbus networks and perform interesting tasks.
As I get the time, I will try to develop other Function nodes for different commands.
But please keep in mind that not all modules respond the same way to similar commands, so it’s best to keep referring back to the protocol documents for each module when trying these out.
Good luck