Xerox 4215, Installation Planning Manual, Page: 53 / 83

INTERFACE SUPPORT
Serial interface
Serial interface connector
The serial interface uses a standard female B-type 25-pin
connector as shown in figure B-5. Xerox recommends that you
use the Xerox RS232 25-foot serial cable, part number 9R80254.
Figure B-5. RS232C serial interface connector
Serial interface connector pin assignments
The serial interface signals and functions are listed in table B-3.
Table B-3. Serial interface connector pin assignments
Pin Signal name Function
1 Frame GND Frame Ground
2 TXD Transmitted Data
3 RXD Received Data
4 RTS Request to Send
5 CTS Clear to Send
6 DSR Data Set Ready
7 GND Signal Ground
8—19 No connection
20 DTR Data Terminal Ready
21—25 No connection
Null modem
Since both computers and printers are Data Terminal Equipment
(DTE) devices, you need a special cable or adapter called a null
modem to connect them together.
A null modem is a modem eliminator in which all of the control
signals are cross-wired so that the device on each side of the
interface “thinks” that it is receiving signals from a modem.
B-6 XEROX 4219/MRP AND 4215/MRP INSTALLATION PLANNING GUIDE