Add two RS422/485 serial ports through a standard or low profile PCI expansion slot 2 Port PCI RS422/485 Serial Adapter Card with 161050 UART PCI serial card supports maximum data transmission rate of 128Kbps rs422 serial card rs485 serial card dual port serial card 2 port rs422 pci card PCI serial expansion card supports both 2-wire and 4-wire RS485 modes