7i76 and servodriver junction electronic

I have board 7i76 that controls drivers maxine EP1C.
Directly connect 7i76 board to servodrives is not possible. Servodriver somehow not see pulses of step/dir signals. I was made electronic gain using optocouper to change voltage from 5 to 24V. Servodrive see such pulses well. But it's very slow system and have very low band, only 200kHz maximum. And also very unreliable, if something heppens with dir output, it will move only in one direction. I had such problem on one chanel with this board.

I want to change it to differential connection as on picture below


Here servodrive receives pulses from external selfmade board 26LS31 (microscheme used from datasheet of servodrive).It receives only positive pulse to command.

Question? Does it's right connection of 7i76 inputs to this board and GND? What electronic specialists can recomend? Need I any resistors there?
I also want to change stepgen type operation from 0 (ste/dir) to 2 (quadrature). I think it will be much more reliable. Does mesa 7i76 supports high frequencies at dir output?

The 26LS31 will only reduce the signal strength from the 7I76...
The 7I76 differential outputs swing to 5V with no load, the 26LS31 will only swing to
about 3.5V with no load, so a direct connection to the 7I76 (preferably differential) should
work better.

The maximum stepgen output frequency depends on the FPGA cards clock
PCI cards like the 5I25 are good to about 4 MHz step rates , Ethernet cards are good to about 10 MHz

I know that direct connection to 7i76 much better than any intermidiate microscheme. But if you remember my topic forum.linuxcnc.org/39-pncconf/33991-conf...6x1d?start=20#106624
I had big problems with this servodrives. And only that board sovled my problem. Now I'm not sutticfied with that decision. And want to rebuild it. Could you help me in that, Peter? Does that scheme above is right?

If the 7I76 does not have damaged outputs, the 26LS31 circuit will only make things worse (less rather than more drive)
It sounds like you somehow got drives that do not accept 5V signals so only a level translator (to 12/24V perhaps) will work