4 axes + pwm spindle

The Mesa cards (with the right firmware) typically offer at least 8 encoders, stepgens and PWM generators.
(With the advantage that PWM frequency can be hundreds of kHz.)
The 5i23 has a bigger FPGA than the otherwise similar 5i20 and might be a sensible bit of future-proofing for not a lot more expense.

This is also true of the 7i43 (which isn't a PCI card, it connects to the parallel port). I have a 7i43 running my mill/lathe which has 4 axes and a spindle PWM for the milling and the lathe spindles.

Both the PCI cards and the P-Port card can also drive brushless DC motors using the right daughter-cards.

billykid wrote:

5i23 is fully supported, or better 5i20 as ease of configuration?

There are versions of all the 5i20 firmwares for the 5i23 too, and several more too.

I use the inputs as they are putting protection diodes and resistors or take cards already made such 7i37 / 7i42?

That is up to you. My system is wired directly, with some buffers for the high current signals.

total 8 encoder input.

There are a number of firmware files for both cards which will handle 8 encoders (I think there is even one for 12 encoders).
Configuration instrructions are here:
www.linuxcnc.org/docview/html//man/man9/hostmot2.9.html
Especially the section entitled "Config Modparam"

I have problems getting around with 5i20 how it works now with 2 parallel ports?

It doesn't. It is a PCI card.

SVST8_8.bit is an 8-encoder / 8 PWM / 8 stepgen firmware.

You might need to look through the files in /lib/firmware/hm2 to see what suits you best (the xms files are human-readable).
Bear in mind that you can always use less than the max number of function, and any pins that releases can be used for general IO functions.

billykid wrote:

now I'm using this drive: elm-chan.org/works/smc/report_e.html

You should be able to re-use much of that, in effect it is doing much of what EMC2 can do, the difference being that EMC2 does it where you can see what is happening and in more complex ways.

or simply use H bridges enable command cw ccw no CPU
encoder directly on the 5i23?

That would be my solution. The 5i23 can drive the H bridge directly on the basis of the encoder feedback.

Mesa make drives which plug directly into the headers on their cards, if you have not already found them:
www.mesanet.com/motioncardinfo.html (especially the 7i30)

It does not say it there, but I am fairly sure that that will work with 5i23 or 7i43. (Check with Mesa). That would also simplify encoder connection as it includes connnectors and signal conditioning.

However, I have connected encoders direct to the Mesa card header with no problems.

pncconf should get you started, it is a "wizard" which builds Mesa-card configs.