so I have MACH4, ESS.. was running but the original pc was having issues (I love pc's with issues) so I replaced.. so no more pc issues.. now my HOMING cycle went nutz.. now I don't actually home using MACH4 or the ESS.. my axis's are all servos and have built in Homing functions. and I also have a normal plc... when I press the HOME push button all it does is dereference all the axis's and sets an output to the plc.. the plc then triggers a home cycle for each axis in turn.. Z,X and the Y. It then sends a HOME COMPLETE signal to an ESS input. The PMC code in MACH4 controls the output signal to the plc, and when the plc signals the machine is homed, the PMC generates a HOME ALL command. (yes there are one-shots) Except now, when the HOME ALL command is called, sometimes the axis's zero correctly (yes, I have a zero offset, and zero in place checked) but about 24-35% of the time MACH4 generates some weird home position.. almost as if it still thinks it should calculate zero from some position.. and it generates a strange machine offset.. I placed a simple pb on the screen and used it to generate a HOME ALL command. If the machine homes but its in some strange position, I usually can press HOME ALL a couple of times and it finally resets to the zero position and clears the offset. I have a test setup and haven't been able to generate the same result. I'm now nearly 99.8% sure if some sort of a MACH4 installation issue. Can't think of anything else.. I have a few MACH4 setups, and none have ever done anything even close to this. Bizarre but true..   

This issue might be due to a misconfiguration in the PMC code handling the homing sequence. You should ensure the one-shot logic and the home all command are correctly implemented, and verify that no residual offsets are affecting the homing process.

there is no PMC coding... all the homing is done outside of Mach4 and the ESS.. Mach4 is simply configured to HOME IN PLACE when I generate the HOME X, HOME Y, HOME Z, or HOME ALL commands. These should only zero the axis' .. there is no offset.

and yes, all the commands only function one time.. though it shouldn't matter how many times I signal any of those commands.