7i96 + 7i85S

Hi,

I have a running CNC Router which uses a 7i96 STEP/IO Step & dir plus I/O daughtercard.
Now I want to add encoders to the 3 axis (maybe 4 in the future) and plan to use the 7i85S 4 Channel encoder 5 channel Serial RS-422 interface to connect the encoders.
Is it correct that I need to create a bitfile and load that to the 7i96 in order to get this combination up and running?
I've downloaded the 7i96.zip from Measnet.com and looked through the bit files/ vhd files and cannot find a PIN_7I96_7I85S or something close to that. On the other hand I've seen a PIN_7I76x1_7i85sx1D_51.vhd that seems to be almost what I need, just for the 7i76 instead of the 7i96.

Any hint is highly appreciated!

There's probably a closer pin file, like PIN_7I96D_7I78_51.vhd
I can make appropriate bit file if you want, its pretty easy if you are setup

But in any case, making a new configuration is really just a matter of cutting
and pasting from one pin file into another, renumbering instances when
needed and patching the module ID section (the tools are a relatively huge download though)

BTW, the 4 encoder + 5 channel sserial interface card is a straight 7I85,
the 7I85S is 4 encoder 4 step/dir 1 Sserial.

Heres a bitfile/pinfile/PIN_xxx file set

freeby.mesanet.com/7i96_7i85.zip

Yes, I've watched a youtube video of a german guy that describes how to create own bit files and it seemed easy but he also mentioned the long compile times for the bit file.

I only want to go for the 7i85S card because that one is available from eusurplus and the other one is not.

There is no problem with the S model for my use case, right?
Can I still use the bitfile you posted?

Heres a 7I85S version

freeby.mesanet.com/7i96_7i85s.zip

Note that this only supports 3 stepgens on the 7I85S (8 total)
because of 7I96 FPGA space constraints

The 7i85S is the right one. I see he hasn't changed the description over at eusurplus, well he has changed the description but the header line is still wrong. Anyway, I got a 7i85S with the eight differential outputs when ordered from there. Better check with eusurplus if you are unsure.
I use the 7i85S for encoder inputs, works brilliantly.

@PCW I'm not going to use the stepgens on the 7i85S anyway, so thats not a problem for me. Thanks for creating the bitfiles for me!

@Hakan Just to be sure, you ordered a 7i85S at eusurplus and got exactly that one, right?

And one final question, as I'm not going to use the stegens, is it possible to use the spare conectors as GPIO pins or does that not work because of the electronic circuits on the board?

Yes. Got the 7i85S. It has several general purpose outputs as well, that is one of the differences to the 7i85.

You can use spare stepgen outputs on the 7I85S as general purpose 5V outputs (but not inputs)
(this is true of 7I96 stepgen outputs as well)

Do I have to modify the bitfile in order to use the stepgen outputs as GPIOs?

No, all I/O pins on all Hostmot2 firmware configuration are available as GPIO if the secondary pin function (Stepgen encoder etc) is disabled in the driver command line

The hardware supports pin by pin enable but the driver for simplicity only allows
enabling 0..N instances of each module where N is provided on the driver load line.

So for example on a 7I96 with 7i85S where you only need 3 stepgens the hal file
might have:

loadrt hm2_eth board_ip="10.10.10.10" config="num_stepgens=3 num_encoders=3"

This would means that the step/dir pins for stepgens 4 and 5 on the 7I96 and step/dir pins for stepgens 6,7,8 on the 7I85S are available as GPIO. Because of the hardware (buffer/drivers) on the 7I96 and 7I85S these pins can only be used as outputs.