PCIe x1 to 4-Port DB9 RS232 Serial COM Expansion Card, AX99100 ASIX Chipset Industrial I/O Adapter for Desktop PC

This 4-channel RS232 PCIe expansion card is equipped with high-performance AX99100 chip, adding four independent DB9 serial ports to desktops lacking native COM interfaces. Each serial channel works separately without mutual interference, supporting connection to PLC, barcode scanners, serial printers, sensors and access control devices. The onboard protection module effectively resists static and instantaneous voltage surges to avoid communication failure in complex environments. It fits regular ATX, MATX and mini ITX chassis, widely used for industrial control, POS equipment, laboratory test hosts and monitoring workstations. Serial connecting cables are not included.