PCI-X slots for PCIC Cards in Dell servers

I want to know if there is a way of communicating with AB PLCs using controlnet in an architecture where the DCS isa dell rack mounted server with no PCI-X slot for a PCIC communication card to be fix in. i needhelp and suggestions

The best solution is to simply not use ANY non-standard physical layer communications method from a computer.

What PLC's are you using? Maybe a Logix based Ethernet to ControlNet bridge would be easier to deal with?