Kyocera FS-3700 - Manual (Page 105)

C.2. RS-232C/RS-422A Interface
RS-232C interface
Interface Signals
The pins of the printer’s RS-232C interface connector carry the signals listed in Table C.2 . The
table also indicates whether each signal is incoming or outgoing with respect to the printer.
Table C.2. RS-232C Signal Pin Assignments
Pin In/out Signal Description
1 – FG Frame ground
2 Out TXD Transmit Data
3 In RXD Receive Data
4 Out RTS Request To Send
5 In CTS Clear To Send
6 In DSR Data Set Ready
7 – SG Signal Ground
20 Out DTR Data Terminal Ready
Brief descriptions of the signals follow.
FG – Frame Ground – (Pin 1)
This pin is connected directly to the printer frame.
TXD – Transmit Data – (Pin 2)
This output carries asynchronous data sent by the printer to the computer. It is used mainly in
handshaking protocols.
RXD – Receive Data – (Pin 3)
This input carries serial asynchronous data sent by the computer to the printer.
RTS – Request To Send – (Pin 4)
This output is always held high (above 3 volts).
CTS – Clear To Send – (Pin 5)
DSR – Data Set Ready – (Pin 6)
Unused.
SG – Signal Ground – (Pin 7)
All signals can transmit between the printer and the host computer to send each signals with
a signal ground.
DTR – Data Terminal Ready – (Pin 20)
This output is used as a buffer nearly-full handshake line. It is held high (above 3 volts) when
the buffer can accept more data.
C.2. RS-232C/RS-422A Interface
C-5