Encoders

hello, I just started taking my first steps in linuxcnc, I have been observing some configurations for the construction of a router, I want to perform the control in closed loop, so the motors that I have do not have Index or Z signal only A and B, for which I thought that setting the Index_enable bit of the FALSE encoder controller should normally count, according to linuxcnc documentation, thanks in advance to anyone who throws some light on this doubt

Thanks for such a quick response, I had planned to carry out the control using a 7i96 tabletop, I would be able to instantiate 5 encoders on this board and in the corresponding vhd header file (not serial connections) and use the expansion port to connect the encoders to the 7i96 board no need for a db25 board?

but if the expansion port pins go directly to the FPGA pins it would only instantiate more encoders in the header .vhd file and modify the .bit and it would not be necessary to have another expansion card or another more expensive card, I have already generated the .bit with ISE DS, I only need the .hal for configuration with linuxcnc

You can instantiate up to 8 (A/B only) TTL level encoders on the 7I96 expansion port
but note that the expansion port is like a parallel port: just TTL signal levels
and no protection from overvoltages etc, so if you accidental connect a pin to frame ground
(with 1V of AC noise) or 12V you will kill the 7I96. Better to use a 7I89 (8 TTL or DIFF encoder inputs)
or 7I85S (4 step/dir outputs 4 encoder inputs) these encoder inputs will take +-25V fault voltages without harm

If you do use the bare expansion port inputs wired to distant encoders its best to insert a series resistor
in every signal (say 220 Ohm ) to prevent damage from shorting to noisy frame grounds