Bematech KC-4112 Rev.1.1 - Manual (Page 14)

User’s Manual
14
Chapter 4
Communication Interfaces Communication Interfaces Communication Interfaces Communication Interfaces Communication Interfaces
Communication between a host and the printer can be performed in three communication protocols: USB,
Parallel or Serial RS-232.
Serial interface
The printer’s RS232 serial interface uses a female DB-25 connector. The serial port can operate using the
DTR/DSR mode, with 7 or 8 data bits, with or without parity, even or odd parity, one start bit and one or more
stop bits. In the RS232 standard, the logic low level corresponds to a +12V voltage level and a logic high level
corresponds to a –12V voltage level.
DTR / DSR mode
In this mode, the printer’s DTR line controls the flow of data sent from the host’s TX line and received by the
printer’s RX pin. In this case, when the printer’s DTR signal is low (+12V) the printer requests the host to send
data. When the DTR signal is high (-12V) the printer tells the host to stop sending data.
DB-25 Serial connector
The serial cable needed for the DTR / DSR mode is shown below.
Figure 9