SUNIX IPC-E3204S, Industrial 4-port RS-232/422/485 PCI-Express Serial 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 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. SUNIX IPC-E3204S board is provided with 2KV IEC6100-4-5 Level 3 Surge Suppressor and 15KV IEC61000-4-2 ESD Discharge Transceiver. Besides, 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.