This setting defines parity for the first serial port (RS-232). When set to None, no parity bit is added to the serial data. When set to ero, a 0 bit is added. Even and Odd work like normal parity functions. Make sure you know what your system needs, for example, XMODEM must use 8 data bits and no parity (set to “None”). This setting must match the transfer rate from the personal computer.