Ok, so I tried an idea. I loaded the mach4mill profile and was able to setup the OB1 on the spindle, excellent. Everything works, better than on the lathe profile I might add. However the spindle is still not working. I cannot even get it to turn now. The relay clicks on and off when I hit an M03 code (not for M04) and the lights switch (see attached). The pmdx107 test mode works and the voltages show around 8.4v (2300rpm) at max, 2.3v at 700 RPM. As Bob recommended I tried the voltages on pin 16 and the pc_gnd and it dropped from 4.8v to 0v as hoped for. Any thoughts?
Just to make sure I understand: when you measured the 8.4V at 2300 RPM and 2.3V at 700 RPM on the (I presume) PMDX-107's Aout and Agnd terminals, was that using the PMDX-107's test mode (for full speed and 30% of full speed)? Or was that using M3/S********* commands from Mach4? If so, what "S" commands did you use?
And when you checked the voltage on PMDX-126 connector J6 "16" and "PC gnd" terminals, what were the "S" commands that corresponded to those voltages? And were you able to get any voltage between 0V and 4.8V, for example by trying to set the spindle speed at 1/2 of full speed?
In the two pictures you posted, it looks like the pin 16 LED on the PMDX-126 is on full brightness in both pictures. The pin 16 LED should vary brightness as you change spindle RPM. It also shows that the PMDX-107 does not see a valid PWM signal as its "PWM" LED is off, as are the "Fwd/Run" and "Rev/Dir" LEDs.
And a curiosity, though this is a secondary concern over getting the PWM to control spindle speed and DO NOT CHANGE THIS NOW - I notice that you have the PMDX-107 DIP switch #4 in the "up " position, which tells the PMDX-107 to ignore the "charge pump OK" signal. I thought you were using the charge pump signal on pin 17 from the ESS to the PMDX-126. If so, we normally recommend having the PMDX-107 also pay attention to the charge pump signal. This is a minor issue as the PMDx-126 should guarantee that the PWM signal is disabled if the charge pump signal goes away. If you wish to change it, wait until the PWM issue has been fixed (debug by only changing one thing at a time, otherwise you have no way of know which change fixed the issue).
I think it may be time for you to post a copy of your profile, so we can see what you actually have configured. You can either post just the "Machine.ini" file from profile directory (i.e. C:\Mach4Hobby\Profiles\YourProfileName\Machine.ini), or you can create a profile package and post that. Go to the Help->Support menu and select "Create Profile Package". You will have to change the file extension from ".m4prof" to ".zip" in order to upload it here. I can look at the general config items but I'm not sure I can be of any help on the ESS specific settings.
Bob