Tormach ETC on my 770MX

I just bought the ETS for my 770MX,
I noticed it did not come with a base to mount on the mill table. I assume I should make my own.

I do have a question about using my Haimer so it has a proper zero for the tool setter.
How do I zero the Haimer to the ETS. Do I use a gage pin and press down until its flat and then subtract the gage pin , same as I did for the manual tool setter.
Is that the same as 0 electronically.

Thank you

@Laurence_Oberman When I am setting up a new machine I set the Haimer, ETS and Passive probe heights based on a reference height. When setting up the ETS you would have nudged the nose of the spindle against a 123 block or something similar and at that time you can set the Haimer length off of that reference height as well. I hope that helps.