Connecting RS-232
Devices
When connecting RS-232 devices refer to the following diagrams.
Note: The shield is connected to common at one end only. It is
recommended not to use the shield as a conductor; if necessary, use a
separate wire. Some devices may require certain hardware handshaking lines
to be asserted. Refer to appropriate documentation.
Connecting IBM XT or Compatible
Figure 9.2 shows how to connect an IBM XT or compatible computer.
Figure 9.2
Connecting IBM XT (25-Pin) or Compatible
DL20 RS-232 Port
RS-232 IN (CLEAR)
RS-232 OUT (RED)
GROUND (BLACK)
The wire colors refer to the Allen-Bradley 2706-NC1 and -NC2 cables.
Connecting IBM AT or Compatible
Figure 9.3 shows how to connect an IBM AT or compatible computer.
Figure 9.3
Connecting IBM AT (9-Pin) or Compatible
DL20 RS-232 Port
RS-232 IN (CLEAR)
RS-232 OUT (RED)
GROUND (BLACK)
The wire colors refer to the Allen-Bradley 2706-NC1 and -NC2 cables.
Chapter 9
Installation and Maintenance
1
7
2
6
3
7
8
1
7
2
3
6
5
8
Computer COM1
(25-Pin) Serial Port
SHIELD (frame ground)
TXD
RXD
SIGNAL GND
Computer COM1
(9 Pin) Serial Port
SHIELD (frame ground)
RXD
TXD
SIGNAL GND
9–5