Hello Everyone,
I red this thread with much interest as I have the exact same problem as PillyWilly.
France, W10 US, UCR201, UP Squared Celeron single board computer, UC100, Ger 2017 Screenset.
If I try using the auto-zero button on the pendant, I get 1 of the three scenarios described by PillyWilly, the most common being, slow motion to switch plate, retract, and full speed crash into sensor.
OK so now not touching the pendant auto zero button but keep it plugged in and using the screenset button to zero my tool and launch the machining. ---> I end up with a negative ~3mm differential between the "set" z 0 and the actual z position, after 10minutes of running my G code my tool was going through my machine bed. I cant say for sure if the 3mm differential is there from the moment I zero my tool or if it happens overtime while the program is running but I was cutting some ply in 2mm passes and by the sound of it it seems the first pass was much deeper than it should , so I suspect the differential is there from the start)... this being said and having those 2 issues I did no further investigation, I unplugged the pendant and everything went back to normal. The pendant is now collecting dust on a shelve since 4 months .... not the use I intended for it .... a fix would be very welcome