Rebuilding a Cisco console cable for serial + power cable for the GPS kit.

A cisco cable is meant to connect a pc or laptop to the console port of a Cisco device.  The cable is a set containing these parts:

The original wiring of this Cisco cable with its DB9-RJ45 adapter is according to this table:

 signal (PC)  DB-9 adapter   color    RJ45 adapter        flat RJ45 cable   flat RJ45 cable 
(out) RTS 7 blue 1   1 8
(out) DTR 4 orange 2   2 7
(out) TXD 3 black 3   3 6
ground 5 red 4   4 5
ground 5 green 5   5 4
(in) RXD 2 yellow 6   6 3
(in) DSR 6 brown 7   7 2
(in) CTS 8 white 8   8 1

Notice that the flat RJ45 cable is a so-called "roll-over" cable, where 1 to 8 is connected with 8 to 1 respectively on the other end.


The RJ45 connector of the GPS kit is described here (only relevant signals shown):

 contact   direction (GPS)    level  description
8 input supply supply. +5V stab. or +10 tot +25V unstab. (SW5) 
7 both ground ground 
3 input RS232 NMEA data port input.
2 output RS232 NMEA data port output.

To create a cable with which the serial information can be transported to the pc's serail port and the power supply is inserted on the RJ45 cable the wiring inside the DB9-RJ45 adapter needs te be changed.

Prepare the USB or PS/2 cable by cutting it at the correct length (the distance between the USB or PS/2 port and the serial port of the laptop) and strip the cable in such a way that the 2 wires that contain the power supply are left over. (look here)

Make the following connections:

Use short pieces of thermal schrinking tube to isolate the joints, and use a tie-wrap over the supply cable to secure it in the adapter.  Make sure the power supply jumper on the PCB is in the 5V position.

Double-check the wiring, and connect the cable to the laptop or PC and the GPS receiver.  Check the supply voltage on the GPS module - it should be between 4,75 and 5,25V.