Yeah drives have power, and I can see the LEDs on the UB1 flashing to indicate the Step and Dir pulses are sent. Unfortunately I'm away from home for the weekend so testing is delayed!

Have just found this from vrasak himself (post #3) - so perhaps I'm just confusing my logic states as per Neale's suggestion, and really the drives just need to be configured active low. Vrasak refers to the need to switch the fault state, but not the enable, which is suggestive :)

https://www.cnczone.com/forums/uccnc...cnc-forum.html