Thank You Both for the input! The network is already setup as you guys mentioned, the shielded wire on each drive is connected to the AGND terminal and at the Nano is connected to the 0V. All but Drive2 is not communicating at all, with UART Errors.
My next step is to enable to built in bias terminator in the last drive (Drive4) to see if that works, if it doesn't work I will disable it and then add the 1K by the Nano and try again as you mentioned.
[---------------RS 485 Network--25' max-------------]
====\/=======\/======\/======\/
[Drive1] [Drive2] [Drive3] [Drive4]
I have also reached out to ABB to see if there's anything else I can do, so far still waiting....
My very last attempt to fix this id everything else doesn't work, I will try to use the Auto485 and connect it to the drive via RS232 back on the network with via 485 , I haven't try this yet... Keep you all posted.
Thanks,
Ed