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This error can be caused by a temporarily dropped connection between the computer and the Pocket NC mill or by a program that is so large and complicated that the Beaglebone’s processor cannot keep up.
Check that the connection between the computer and the machine is good.
Try slowing down the feed rate or reducing the file size of the G code file by breaking it into more than 1 operation or by loosening the tolerances in the toolpath and reposting it.
Problem 3: “Cannot unhome while moving _ Axis” or “Homing Sequence Already in Progress”
Explanation: This error means that a homing process is currently underway, but a second homing process has been commanded.
Possible Solutions:
Use the Home All command by itself and wait for completion before issuing another homing command.
Home individual axes one at a time and wait for completion before starting a second homing sequence.