Last night I was running a few projects on my Shapeoko Pro XXL (a few simple pocketing toolpaths). The first two pieces ran flawlessly, but after securing my third workpiece on the router table, using the bitzero to zero the bottom left corner of the stock piece (just as I had done on the previous two workpieces), as the machine then began to run the new file and use the bit setter on the newly loaded cutter I received the following error message:
GRBL Alarm 4:
Probe Fail. The Probe is not in the expected initial state before starting probe cycle.
I then parked the machine, powered down, closed Carbide Motion and restarted everything back up. Upon every machine initialization since then I have received the same message. I have checked that the bit setter is clean, all connections are secure and intact, the bit zero was not tripped on anything, and any other simple issue that I could think of. Ever since the initial error message I have noticed that upon restarting the machine everything seems to be as it should be, but upon the initial depression of the bit setter during initialization the red indicator on the bitsetter stays illuminated, even after the cutter bit has released the bitsetter and is preventing the second depression of the bitsetter.
In summary it appears that when the bitsetter is initially depressed and then released, the machine is recognizing that it is depressed but not recognizing that it has been released which in turn prevents it from performing the second, fine tuned depression of the bitsetter upon machine initialization and/or when loading a new bit.