2 port standard 9-pin RS-232 serial ports allows to connect to serial devices. PCI-E to serial TX. Compliant with PCI Express Revision 1.0a. Bi-directional speed from 110 to 230400 bps/port. Support standard serial mode, plug-n-play, automatic identification. Support RS232, RS485 & RS422 modes. Support hardware and software flow control. Support for Windows 2000/XP/Server 2003/XP 64-bit/Vista/Win 7/Linux/Dos/Mac OS.