5i25 + 7i76 + 7i85 setup

So now I have these boards, I want to set them up for lathe with 2 linear encoders, spindle encoder, 2 servo drives and a VFD - plus limit switches etc.

PnCConf doesn't seem to offer an option for the 7i85 with the 5i25 selected. I can see options for either 1 or 2 of the 7i76s and a few boards are listed in the "sanity check" area but nothing related to 7i85. I need to end up with one 7i76 and one 7i85 coming off the 5i25.

What is required for me to get this set up? I've searched for relevant posts but mostly they relate to 7i76e which is presumably quite different. I'm guessing the 7i85 would piggy back directly off the 7i76e. Am I going to have to get busy and attempt some form of HAL file to make connections or is there a bitfile that can be used?

Thanks

I wonder if anyone can offer any guidance on how to proceed here, as I am not sure how to take this forward.

Perhaps @PCW would be in a position to help?

Basically if you intend to use linear encoder feedback instead of a "open loop"
step/dir setup you need to:

1. Setup the encoder scales and directions
2. Get the position feedback from the encoders rather than the stepgen position feedback register.
3. Retune the PID, (you will have to lower the P term considerably of you will have sever oscillations

This would be identical on a 7I76E+7I85 setup except the pin names would be different
(hm2_5i25.blah-blah.blah vs hm2_7i76e.blah.blah/blah)

So in pncconf, within the configuration page, do I select 5i25 under "board name".



Or do I select 7i76e


I can't see 7i85 anywhere, which is confusing me.

You would select 7I76x2 with one 7I76, make a complete working
open loop configuration (including homing ,spindle control etc)

At that point you are done with pncconf and the changes I indicated above
would be implemented in the hal/ini files

Thanks - that is a really useful help for me. I'm very much starting out here as you an probably tell!

I was planning to do everything open loop initially as you suggested but with the right foundations in place so that I don't have to start over at the last stage.

Appreciate the help!