IBM InfoWindow II 3153 User Manual

Introduction
12
Terminal to Modem (DCE) or Host
Refer to the diagram below to understand why a null modem adapter may
be needed when connecting the second serial port (SES2-AUX) to a modem
or a DCE host. The first host will connect directly without a null modem
since it is a DTE device.
DTE
SES1 EIA
Modem
Transmit
Receive
DTR
DSR
Transmit
Receive
DTR
DSR
pin2
pin3
pin20
pin6
pin2
pin3
pin20
pin6
D
C
E
Host
DCE
SES2 AUX
Modem
D
C
E
Host
Receive
Transmit
DTR
DSR
Transmit
Receive
DTR
DSR
pin2
pin3
pin20
pin6
pin2
pin3
pin20
pin6
Terminal to Host (DTE) or Printer
Refer to the diagram below to understand why a null modem adapter may
be needed when connecting the first serial port (SES1-EIA) to a host port
without a modem (Most serial printers are DTE devices and most hosts are
not). The second port (AUX) will connect directly without a null modem
since it is a DCE device.

IBM InfoWindow II 3153 Specifications

General

Brand	IBM
Model	InfoWindow II 3153
Category	Monitor
Language	English