Electrical spec of DaisyLink

What is the electrical spec of DL?
What kind of cables are needed?
How long can these cables be?
Can I use Star/Tree architecture?
How many modules can I link?

So I assume it’s ‘only’ good for on board and short distance communication.
I’m more looking for a up to 50m bus.
Then I think I will stick to RS485.
DL also seems to be Gadgeteer related, which I have currently not planned to use on the SW side.