Can the on-board relay be assigned to 1 of the 8 outputs independently (eg. assign to output 8 and only activated when output 8 is on) ?
I do not want to use it as a master controlled by the other 7 outputs (eg. 8 controlled by 1-7)
I dont see an option for this in open sprinkler app.
As I want to use the relay to drive another relay for lighting use.
The relay feature has been retired since early this year. It’s partly because very few users are actually using this feature, and those who do can use an external 24VAC relay instead. A while back I wrote a blog post about using 24VAC relay with OpenSprinkler: https://opensprinkler.com/using-24v-ac-relays-with-opensprinkler/
In addition, for controlling powerline devices, you can use the RF station feature in conjunction with off-the-shelf RF remote power sockets, which are easier and safer to work with than relays.