I have Firefli controllers and strings, but have converted them all to the Open/DMX protocol.
You must have a D-Light RS485 dongle connected and visible to xLights.
Jon if they are in Open dmx format why would you need a Dlight dongle. Would not any dmx open dongle drive them. I don't have any just asking.
Since there aren't many people on this forum using the Open Firefli in DMX mode, I didn't get very specific.
The Firefli controller, in DMX mode, accepts DMX commands from any DMX dongle.
BUT, it is configured using a tool we (on the D-Light forum) call Dewey-Config. It was written by "Dewey"
Dewey-Config was written to find a single D-Light V3 USB Dongle. If there are other dongles, it gets confused.
Once configured (start channel, Unit ID, linearity adjustment, grouping), you won't need that dongle again.
While I suppose "Dewey" could re-write it to be more universal, nobody has pressured him since we all have D-Light dongles from initial purchase.
I use 5 Firefli strings on 5 PVC arches, run by 2 controllers. One controller has 3 strings (48 pixels), the other has 2 strings (32 pixels). Once controller can handle 5 end to end strings, but you must configure it first so that it knows. That limit is a controller Power limit more than a software limit. They are getting rather old now but still work reliably. Just for old-times-sake, I'll probably use them until they die a natural death.