Comtrol ISA - Manual (Page 5)

RocketPort® ISA Hardware Installation 5 of 9
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.
DB25 Pinouts
The following figures and table illustrate connector
information for DB25 connectors.
* All RS-232 signals are present in RS-422 mode. The
Quad/Octacables do not support RS-422 mode.
Building DB25 Female Loopback Plugs
Loopback plugs are used with
the diagnostics to test serial
ports.
This loopback is used with
Quadcable, Octacable, and the
Surge interface boxes. 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
Building DB25 Male Loopback Plugs
Loopback plugs are used with
the diagnostics to test serial
ports.
This loopback plug is used
with the standard 8- and 16-
port DB25 interface boxes.
• 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.
• Pins 15 to 19
• Pins 17 to 25
Pin RS-232 Signal RS-422 Signal
1 Not used Not used
2 TxD Not used*
3 RxD Not used*
4 RTS Not used*
5 CTS Not used*
6 DSR Not used*
7 Signal ground Signal ground*
8 DCD Not used*
9 to 14 Not used Not used
15 Not used RxD+
16 Not used Not used
17 Not used RxD-
18 Not used Not used
19 Not used TxD+
20 DTR Not used*
21 to 24 Not used Not used
25 Not used TxD-
Pin 13 Pin 1
Pin 25 Pin 14
DB25 Female
Pin 14 Pin 25
Pin 1 Pin 13
DB25 Male
Pin 13 in 1
RS-232 Only (Back View)
Pin 14 Pin 25
Pin 25 Pin 14
Pin 13 Pin 1
RS-422 Only (Back View)
Pin 13 Pin 1
Pin 14 Pin 25
RS-232 Only (Back View)
Pin 25 Pin 14
Pin 1 Pin 13
RS-422 Only (Back View)