Best way to add 4 analog +/-10V to 5i20/7i33/7i37?

Hi, all;

I've just about gotten to the point budget wise I can buy some additional servo channels to play with. My 5i20/7i33/7i37 combo works well, but it has only four analog outputs. This is an issue because for the next incarnation of my mill I want to use both a servo spindle and a 4th axis, totalling 5 servos to control. Additionally, I'd like to try using the bldc module for servo control, which means for 3 axes I need two analog outputs per axis. To make things more interesting I have an MPG I'd like to connect to an encoder input.

Since the 5i20 has three 50 pin connectors, could I just add another 7i33 and use it with the two existing cards (three daughter cards total)? If it works and I did, would there be limitations of any kind?

I'd pretty much settled on buying a 5i25+7i77 combo, but if I can do something cheaper I can do it sooner. Also, even for that combo I'd probably need something like a 7i83 in addition to the 7i77 to get enough servo channels to play with, which drives the price up even more. Hence I'm wondering if there's a cheaper way to do it.

Alternatively if anyone can suggest the cheapest way to get 8-10 +/-10V analog outputs with 6 quadrature encoder inputs and at least 16 digital in and 16 digital out, I'd like to hear it.

Thanks for any info,

Erik

Yes, you can simply add another 7I33 to get 4 more encoder inputs.
The only limitation of this card setup is there is no more I/O expansion available

There are a few other options for more I/O: for example you could add a 7I52 which would
give you 6 more encoder inputs and 6 sserial channels for I/O and analog expansion
(at a cost of course)

Thanks. I'm thinking what I may do is just add the 7i33 now and start experimenting, then when funds permit swap the whole board set out for something with more ports. I could use another set of Mesa cards for another project anyway, and likely it'll need less I/O than my mill does...

Erik