Weerasak was kind enough to help me with the E-stop circuit to. You put all the normally closed inputs that you want included in your safety circuit on inputs X105 - X115*. Then assign X102 as your E-stop input in UCCNC. If any input is not OK, then the UB1 will cause an E-stop input and UCCNC will go in to Re-set. It also is part of the Output Signal Switching Device , OSSD, and it can open and close a power contactor if desired. Its described pretty well in the UB1 owners manual but it wasn't making sense to me until I saw how it would work with the Clear Path HLFB.
I don't know if the limit override Software button in UCCNC will let you recover from an alarm condition with this circuit? Or, if it requires an actual switch? I see the Override input on the UB1 for this purpose but I guess I'll have to experiment a little with it and report back.
Thank you Weerasak at http://www.cncroom.com for the assistance.
* - This requires the solder bridges on the back of the UB1 to be soldered closed to be included in the OSSD circuit.