I've had Uc100 for quite some time without any issues. Lately, I noticed that  the UC100 gives me a "disconnect" error with USB, which stops the job midway. If I disconnect the USB cable from the pc, the z axis starts moving up until I reconnect it again. Is there a way to prevent this in mach3 ? With the z axis moving up, I have no time to diagnose the problem, which forces me to turn off the entire system ans start all over again.
tony

Once the UC100 is disconnected, the axis shouldn't be moving at all. Sounds like a serious noise issue is both causing the disconnect, and causing the Z axis motion?