Comtrol RocketPort Plus Universal PCI - Manual (Page 14)

14 - Connecting Serial Devices RocketPort Plus Universal PCI User Guide: 2000369 Rev. C
Connecting Serial Devices
DB25 Loopback
Plugs A loopback plug is a DB25 serial port plug with pins wired together. You can use a
loopback plug with application software (for example, Test Terminal) to test serial
ports.
The Quadcable and Octacable use the RS-232 female
loopback plug. To build a DB25 loopback plug for a
Quadcable or Octacable, wire the following pins
together:
• Pins 2 to 3
• Pins 4 to 5 to 22
• Pins 6 to 8 to 20
Pin 13 Pin 1
RS-232 Only (Back View)
Pin 14 Pin 25