I'm trying to remember!
I only did this before Christmas and have already lost it...
There are two sides to the controls, 110v and 24v DC.
All the limit switches are 110v and are the "last chance" cut off.
The enable signals and DC interlock, I have wired to the CSMIO so that Mach 3 controls them. Then you can set soft limits in Mach 3 and everything behaves like it did before. You can run to the end of travel and it will stop before hitting the final buffer of the 110v system. It will not trigger a reset and you can jog back off again, as before.
The pulse suppression thing is for the Heidenhain control. It is not needed now. You get your reference from the encoders on the servo motors and ref via mach 3 and CSMIO.
I assume you have changed the encoders on your existing motors? Or you had more modern motors than me?
To power my 24v side, I did away with the ancient basic regulator fitted and put in one of these (or similar)
https://www.amazon.co.uk/Surom-Universal-Regulated-Switching-Computer/dp/B071W121H7?ref_=fsclp_pl_dp_4 It even runs from 110v.
Les