Communicating with RS485

So i have a set of servo drivers, that uses a RS485 communication protocol.
The issue weve found is that running those of a normal USB to RS485 converter doesnt really work well.

And now been digging thru the mesa card options and found this card that seems promising. the 7i88.
its a DB25 expansion card but the question now comes down to, can this card communicate with a 6i25 or a 7i92 card?

And if so, is it possible to talk to a RS485 device, if one writes a custom hal component, communicating to the device thru hostmot2 ?? And would that be in the realtime space necessary?!

You would need a real-time driver that speaks the cards protocol

When you say realtime driver for the card. You mean a driver for the 7i88 card then i suspect? And it has to be compiled into linuxcnc??

Either a hostmot2 integrated driver for the specific protocol or a real time hal component that
handles the protocol talking to the hostmot2 pktuart

Oki, that makes sense. yeah the protocol driver for simplemotion is readily available and compiles no problems on linux and tests been done for USB devices as said.. I just wanna find a way of replacing the usb device, Because the simplemotion protocol allows for chaining 32 devices in a ethercat style setup using a framebuffer approach to talking to the drives.