Personally, I wouldn't even bother with the MF (Enable) or the Pend. Not sure what you would even use the Pend for?
If you want to use the MF, just wire it to a UB1 output pin.
Here's some info on wiring an Alarm signal.
forum.cncdrive.com • View topic - UCCNC ETH300/UB1 Servo Alarm Setup
https://www.cnczone.com/forums/uccnc...cnc-forum.html