Z HOME reversed itself

[maginskyk]

HI, I am running a small xyz mill with a PMDX422 and MACH4. On Friday everything was working perfectly. I turned on the system this morning and all by itself, the Z axis is homing in the wrong direction? I shut down and restarted. Same problem. I checked the MACH4 configuration and its supposed to be homing in in the POS direction. I switch it from pos to neg and the Z did switch direction. Is this a known problem? Please assist. Thanks Keith.

[12strings]

This should not happen unless a setting changed, or the wiring changed.  Can you still move the Z axis in both directions?  And is the "positive" direction still the same as it always has?  In other words, is it only the homing direction that has changed behavior?

What version of Mach4 and the PMDX plug-in are you running?  There was a PMDX plug-in update a little while ago that fixed something that was corrupting the configuration file (machine.ini).  Look here to see if you have that version:

http://www.pmdx.com/PMDX-SmartBOB-USB-Plug-In