Wiring - 24v field and 36v stepper drivers

Sorry folks,
just having a brain fart moment.

I assume I have to tie the field power ground to the stepper motor ground for the signals to work.  Logic says yes but tieing high and low current systems together seems a little counter intuitive. 

Tia. Pete

It depends entirely upon the specifics of your system. If your drives have opto-isolated IO then you don't have to connect the grounds (and probably shouldn't).

Linked grounds but the real problem was the drivers set for 24v signals but the Mesa giving only 5v even when on 24v field power.

X and Y motors now working but Z not responding.

The field I/O on Mesa cards is not related or connected to the step/dir interfaces

Mesa cards have 5V step/dir signals so the motor drives needs
to be set to accept 5V signals.

If you have a drive that does not work, the first suggestion is to
double the step time (don't use the minimum specified time)

Thanks for the clarification.
All three motors and drivers (CL57T) are supposedly the same so I added 10 percent to the minimums for less error prone use.

The only exception is that the z drive is a V3 not v4 like the X and Y. This means that the set up is done by rs232 not just switches.

I have contacted the manufacturers as even bypassing my own wiring I am still getting encoder wiring error so I am starting to suspect a bad driver.