User`s guide

Appendix D - Asynchronous Communications
OMG-ISO-COMM Page 18
Because each bit in asynchronous communications is sent consecutively, it is
easy to generalize asynchronous communications by stating that each character
is wrapped (framed) by pre-defined bits to mark the beginning and end of the
serial transmission of the character. The data rate and communication parameters
for asynchronous communications have to be the same at both the transmitting
and receiving ends. The communication parameters are baud rate, parity, number
of data bits per character, and stop bits (i.e. 9600,N,8,1).