Printer Firmware version required: For Lexmark T520, T522, T620, T622 - 541.019 or later For Lexmark W820 - 611.019 or later Configuration settings for the serial interface are available using the Serial Opt Menu from the printer's operator panel. Baud rates from 1200 to 115.2K are supported. Baud rates:1200, 2400, 4800, 9600, 19.2K, 38.4K, 57.6K and 115.2K 7 bit or 8 data bits Parity - Odd, Even, None, Ignore Start and Stop Bits DSR/DTR Data Flow control with DTR pacing, DTR/DSR, XON/XOFF, XON/XOFF/DTR, or XON/XOFF/DTR/DSR flow control protocols indicates factory defaults It is recommended that a Lexmark RS-232 serial cable (P/N 1038693) be used to avoid compatibility problems. RS-422 is not supported. See the Technical Reference for more information about the serial and parallel interfaces.The RS-232C Serial /Parallel 1284-C Interface Card installs into the printer's PCI-based, Internal Solutions Port. It supports a standard RS-232C interface using a 25-pin D-shell female connector and a parallel 1284-C compliant interface using a 36-pin D-shell female, bi-directional connector.The RS-232C Serial/Parallel 1284-C Interface Card is for use with all models of the Lexmark C750, C910, C912, T520, T522, T620, T622, W812 and W820 printers that have an open slot.