User Guide

8
DB25 Interfaces
DB25 Interfaces Use the following subsections for
DB25 interface connectors. Standard
interface boxes use female DB25
connectors, while the Surge interface
box, Quadcable, and Octacable
fanouts use male connectors.
This table shows connector information for DB25 connectors.
Building DB25
Female Loopback
Plugs
Loopback plugs are used with the diagnostics to test
serial ports.
This loopback is used with the Quadcable and
Octacable. Wire the following pins together for an RS-
232 plug.
•Pins 2 to 3
• Pins 4 to 5 to 22
• Pins 6 to 8 to 20
Wire the following pins together for an RS-422
loopback plug (Surge interface box).
• Pins 15 to 19
• Pins 17 to 25
Interface Boxes Quad/Octacable
Pin
RS-232 Signal RS-422 Signal RS-232 Signal
1 Not used Not used Not used
2TxDNot used* TxD
3RxDNot used* RxD
4 RTS Not used* RTS
5 CTS Not used* CTS
6 DSR Not used* DSR
7 Signal ground Signal ground* Signal ground
8DCDNot used* DCD
9 to 14 Not used Not used Not used
15 Not used RxD+ Not used
16 Not used Not used Not used
17 Not used RxD- Not used
18 Not used Not used Not used
19 Not used TxD+ Not used
20 DTR Not used* DTR
21 to 24 Not used Not used Not used
25 Not used TxD- Not used
* All RS-232 signals are present in RS-422 mode. The quad/
octacables do not support RS-422 mode.
Pin 13 Pin 1
Pin 25 Pin 14
DB25 Female
Pin 14 Pin 25
Pin 1 Pin 13
DB25 Male
Pin 13Pin 1
RS-232 Onl
y
(Back View)
Pin 14
Pin 25
Pin 25Pin 14
Pin 13Pin 1
RS-422 Only (Back View)