PWM gen

There is a possibility to connect serial with RS323,RS485 or RS422.
The 7i66 is connected to 7i44 and this is connected to 5i23.
But all the ports on 7i44 are most likely gonna be used up.
On the 5i23 P3 is still available.

Which VFD model? There are some pre-existing HAL components
linuxcnc.org/docs/devel/html/man/man1/gs2.1.html
linuxcnc.org/docs/devel/html/man/man1/hy_gt_vfd.1.html
linuxcnc.org/docs/devel/html/man/man1/hy_vfd.1.html
linuxcnc.org/docs/devel/html/man/man1/mitsub_vfd.1.html
linuxcnc.org/docs/devel/html/man/man1/vfdb_vfd.1.html
linuxcnc.org/docs/devel/html/man/man1/vfs11_vfd.1.html

You can probably arrange to have a high-frequency (up to MHz) PWM generated on one of the 5i23 pins.

Alternatively the 7i83 would do what you want, but seems overkill for an individual analogue output: store.mesanet.com/index.php?route=produc...83_88&product_id=122

It's a pity there isn't a single-channel smart-serial version of the Spinx1
store.mesanet.com/index.php?route=produc...t_id=205&search=spin

It's a commander CD75-750. i don't know with which component this corresponds.

If i generate a PWM on the 5i23, is it still possible to create a 0-10V signal?
I tought the 5i23 only can get 5V on it's pins.

You can get 10V but it needs an op-amp (to change the 0..5V analog to 0..10V)
or some kind of level translator for the PWM before filtering. (our SPINX1 does this)

Heres an example schematic for a 7I66 output filter: