SUNIX SP 2-Port Auto-SW RS-422/485 PCI-E Card (2KV IEC Surge) (DB9) (IPC-E2202S) Expands 2 independent RS-422/485 serial ports with communication speeds up to 921.6Kbps. Designed to meet PCI Express Base Specification Revision 2.0. RS-422 and RS-485 auto detect and switching technology  jumper and software free. On-chip hardware auto flow control to guarantee no data loss. Support Microsoft Windows, Linux, and DOS OS.