Mesa boards choice help

Hi, I'm running 2x lot port +bobs but add on lpt card died on me and I can't find  a replacement.

I'm tempted by Mesa Io cards and anticipating my pc dying too(it's core duo lga775 dell antique) I'm considering thernet cards 7i96s to be specific.
I like all on one solution with one cable for pc and not having to deal with chinesiumn BOBs.
Now, I was running 10khz servo thread, but I read that 1khz is "standard for Mesa ethernet 2khz possible and 4khz extreme, reported by one user here.
 I'm afraid that even at relatively slow feeds/rapids and accelerations I'll run into overshooting problems, in the end 1khz servo thread and 100mm/s rapid moves 0.1mm between updates. 
It's been a while since I went through the set up, so probably I'm mixing something important here but wouldt 6i25 be better at that respect?

If going 6i25 is there a DIY solution for getting analog out of this? I don't think I have it in me to rewrite after reinstal(I'm on lcnc 2.3) spindle vsd modbus module, and I suspect copy-paste may not works in later build..

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The 7I96S at 1 KHz should work fine unless you need extreme acceleration
(say > 5G)

Here is a plot of 1 KHz stepgen errors on a 7I96S at 20 IPS (= 508 mm/S)
with 240 IPS^2 accel (6096 mm/S^2) Note that the error (pink) scale is 10 uInch
per division ( 0.254 u per division)


 

You were probably running base period at 10kHz, not servo period, although it might be, there is no need for it.
I have big industrial machines running 1kHz servo periods with Mesa hardware, never had a single issue in probably more than 10 or 15 years (getting old...).
A single Mesa 5i25 (PCI) or 6i25 (PCI-E) or 7i92T (ETH) can replace both prallel ports, and can do steps at MHz rates on any of 34 pins, while parallel is limited to 5-20KHz.
A Mesa 7i96S would be a better choice, much simpler wiring, and if you do need more I/O, you can use one of the old BOB with it, just needs an IDC26-DB25 adapter cable.
As for the modbus stuff, they are simpler now, but do require some editing, although it might just work depending on what was involved in it, probably spindle pins will need adding a spindle.0. anyway as later versions have support for multiple spindles.

@PCW thanks, i knew i was missing something and barking at the wrong tree.

@tommylight, thanks, Modbus was problem due to chinese VSD being fussy and needing 4 other coils set to change speed, with delays between each coil or it would just ignore it all, took me a week to get it working reliably.

I think i'll go with 7i96e/s just need to find one in resonable price and in stock. Used 5i25 would be cheapest but very not future proof.

Try Portugal at www.eusurplus.com , they should have 7i96S
And there is no 7i96E but there is 7i76E.

Ordered!!