Epson 8900 Series - Manual (Page 209)

Communication Interfaces 10-18
Interface Data Transmission Rate
Because data-transfer operations on the serial interface occur in a
bit-serial fashion, the data transmission rate is measured in bits per
second, commonly called the baud rate. To provide compatibility
with a variety of systems, your printer offers the following range of
baud rates.
q 300 bits per second
q 600 bits per second
q 1200 bits per second
q 2400 bits per second
q 4800 bits per second (the default value)
q 9600 bits per second
q 19,200 bits per second
The control panel setup menu (described in Chapter 2) allows you to
select the appropriate baud rate for your system.
Serial Data Format
The following figure shows the data format for 7-bit and 8-bit
characters. The serial interface can transfer (and the printer can
accept) either 7-bit characters or 8-bit characters, depending on
which character set is in use. In either case, data bit 1 is the least
significant bit (lsb) and the last bit is the most significant bit (msb).