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Null modem – Xerox 4213 User Manual

Page 37

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INTERFACES

Table 1-6.

Asynchronous serial signals and pin assignments

Pin

Signal

Telephone Co.
designation

CCITT
designation

1

Protective Ground

AA

101

2

Transmitted Data

BA

103

3

Received Data

BB

104

4

Request to Send

CA

105

5

Clear to Send

CB

106

6

Data Set Ready

CC

107

7

Signal Ground (common
return)

AB

102

8

Carrier Detect

CF

109

11

Printer Ready

None

None

20

Data Terminal Ready

CD

108

Null modem

A null modem is a device which eliminates both a modem and a
telephone line. Figure 1-6 illustrates typical null modem wiring.
When the 4213 is used with an asynchronous serial interface
connected to a DTE host (such as a PC-compatible), a modem,
modem eliminator, or a null modem is required. Figure 1-6
shows null modem wiring.

XEROX 4213 LASER PRINTER PROGRAMMER REFERENCE

1-15