Need opinion on how, and if I can make a EDM machine with linux CNC :)

There is also 7i96 for ...i do not know but much cheaper.

aliaj00 wrote:

if i am going to buy an IO i would like to have the ethernet preferably less than 200$.

regards,
Tim

If you don't need a lot of I/O the 7i96 is $120. if you have a lot of i/O the 7i76e is $200.

JT

Both cards offer a reasonable number of GPIO pins in addition to the step/dir outputs.

The 7i76E has 16 outputs rated 5 to 28V at 300mA and 32 inputs which sense 5 to 32V

The 7i96 has 6 outputs and 11 inputs. The outputs are 2A rated devices acting like a switch (so slightly more adaptable than the 7i76E) and the inputs can sense up to 36V in either sourcing or sinking mode.

So, if 6 outputs and 11 inputs is enough (and I would rather expect it to be for a spark eroder) then I would say that the cheaper card might be a better fit for your application.

Either card can be extended by adding one smart-serial IO card to the on-board RS422 port. If you follow the link you will see that these cover most IO requirements.

Also, each card can be further expanded with a second IO card on the expansion header(s). The 7i96 has only one header, but that is enough to add a 7i74 and then a further 8 smart-serial cards (a total of about 400 IO pins!) whereas the 7i76E can take two, for 800 IO pins.

So, in the unlikely event that the 7i96 does not have enough IO, it is easy to add more. You can even plug in a 7i76 (not-E) to make something exactly equivalent to a 7i76E.

One drawback of the 7i96 might be if it is not currently supported by the configuration wizard. (I suspect it isn't, but I am not sure).
This just means that you have to hand-edit the config files. But for your proposed machine, that it likely to be necessary anyway. The config files are intended to be hand-edited, the ability to do so is one of the things that makes LinuxCNC so flexible, you can configure it to do things that the developers never imagined.

Those look nice !