15-pin to 9 pin cable -


I have made by myself the cable to adapt the 15pin connector(FASTRACK) to 9pin connector(PC).

In some modems, the connection is working, in others it isn’t.

I have used RX, TX, RTS, CTS and GND pins.

Do you have any suggestions?
Is it possible to have the complete description how the cable should be done? (connections???)

Thanks a lot for your help.



I think this will be helpful to you.

SUB-D 9CTS SUB D 15CTS (RS232) Signal name

1 (White) 1 (White) DCD (CT109)
2 (Grey) 6 (Grey) RX (CT104)
3 (Violet) 2 (Violet) TX (CT103)
4 (Blue) 8 (Blue) DTR (CT108/2)
5 (Black) 9 (Black) GND
6 (Orange) 7 (Orange) DSR (CT107)
7 (Yellow) 12 (Yellow) RTS (CT105)
8 (Brown) 11 (Brown) CTS (CT106)
9 (Green) 13 (Green) RI (CT125)

Modular Jack 4P/4C SUB D 15CTS (AUDIO)

1 (Yellow/White) ! 4 (Yellow/White) microphone(+)
2 (Red/White) ! 10 (Red/ White) speaker(+)
3 (Green/White) ! 15 (Green/White) speaker(-)
4 (Black/White) 5 (Black/White) microphone(-)

Flying wires SUB D 15CTS (Boot/Reset/GND)

(Pink) 3 (Pink) BOOT
(Blue/White) 14 (Blue/White) RESET
(Black) 9 (Black) GND

With Regards,

Sunil Rao


I can not comunicate with the M1306, my cable is the next:

6-1 (White) 8
2 (Grey) 2
3 (Violet) 6
4 (Blue) 7
5 (Black) 9
7 (Yellow) 11
8 (Brown) 12

Windows vista 64bits

I don´t know the error.

I need help.


Thank you SunilRao

your cable configuration is OK. It is working.

It is working on Fastrack M1306B and Supreme.

A question:

You say “…Flying wires SUB D 15CTS (Boot/Reset/GND)…”

Why GND??? I connected GND between the two connectors.

Again thanks a lot.

Your configuration seems not correct.


To assert Boot and Reset, you connect them to GND. 8)


Note use of the ‘Code’ tags to preserve the layout…

The pinout of the 15-Way connector is defined by Wavecom;
The pinout of the 9-Way connector is a well-defined standard;

But I’m not sure that there is any established standard for the modular jack in this type of application :question: