Sunix IPCP3104 PCI 4-Port 3 in 1 RS 232/422/485 Card with DB9M connector, Up to 921.6 Kbps Support Windows, Linux, DOS, and UNIX industrial standard universal PCI serial communication card, allows users to expand four RS-232/422/485 ports on PC-based system. Each serial port achieves data rates up to 921.6 Kbps and utilizes 16C950 UART with an on-chip 128-bytes hardware FIFO buffer for reliable, high-speed serial I/O. With SUNIX patented Auto-Switching RS-422/485 and RS-485 AHDC™ technology, user can easily manage different serial interfaces selection and RS-485 signal direction control. Under RS-485 mode, the board can connect up to 31 daisy-chained RS-485 devices within a range of 1.2 km. SUNIX serial board supports a wide variety of operating systems, including Windows, Linux, DOS, and UNIX. It is the best serial communicating solution for industrial and harsh environment applications.