The pex8s232485 8 port pcie serial combo card lets you add four rs232 and four rs422 rs485 serial ports to your pc through a single pci express expansion slot this multi port serial card is a single card solution that offers compatibility with nearly any serial communication protocol supporting rs 232 rs 422 rs 485 2 wire or rs 485 4 wire operating modes at data rates up to 460kbps to fit most standard computer cases the card ships with a standard profile bracket installed and includes a