7i96s Extra I/O Daughter Board Selection

I am currently using a 7i96s board to run my mill. When all is done, it will be a 4 axis machine with ATC. However, I have already run out of I/O (mainly outputs), so I'm looking to get a daughter card for expanding that. I would prefer it to be a serial card instead of a P1 connection as I am using the P1 connector for an MPG pendant.

I am planning on having the outputs mainly running relays for sub-spindle control and pneumatic cylinders. The sub-spindle would just be using the same 0-10V signal that the main spindle uses, but with a different set of relays. Maybe connecting a few limit switches on the inputs as well.

I was looking at boards and saw the 7i84 and was wondering if this would be a reasonable selection for this use case. I'm not very familiar with the daughter cards that mesa offers and there are so many of them. Perhaps the 7i73 would be the better option here since I want to add the MPG? That would allow the P1 connector to stay open, but I'm not sure I'd ever need the P1 for anything else and I already have the P1 MPG firmware loaded.

Any input here would be great. I've never run a daughter card before.

I’d jump that way.

Ok, I might go with that then, thanks.