Thanks Dan, that helps. Can you tell me if you used the PMDX126 dedicated e-stop relay in your system (relay K2 I think)? Or did you skip that relay entirely and configure mach(3/4) to use a different logic level pinout? If you are wondering why I ask it is because I originally assumed I was going to wire things up like this: (image sourced from the PMDX-126 app notes).
In the above image it appears that the contactor coil must match the AC voltage sent to the PMDX... From my point of view the only way to use both a 120V contactor coil and the built in estop relay would be to power both the pmdx board and the contactor from the same 120V branch. I could be wrong about this of course.
I did end up getting the PMDX126/ESS to run the sytem... I'll be testing all of this in a few weeks.
Again thanks for the info,
Todd