Epson 8900 Series - Manual (Page 194)

Communication Interfaces 10-3
Introduction
This chapter describes the communication interfaces and provides
information about their use with your printer.
The communication interface transfers data in a fixed and orderly
manner between the host and the printer. Communication interfaces
are of two general types: parallel and serial. Parallel interfaces transfer
all bits of a data byte simultaneously. Serial interfaces transfer data
in bit-serial fashion, one bit at a time.
To provide communication compatibility with a wide range of
systems, your printer offers a choice of any of the following standard
and optional communication interfaces.
q Parallel interface, standard.
q RS-232 or RS-423 serial interface, standard.
q RS-422-A serial interface, optional.
q Current loop (TTY) interface, optional.