Thank you, this helps me to find out what is the "secret" about the serial console on those APs.
We have AP-103 here that use the same connector.
Your Picture shows what is in that unbelivable expensive Cable sold by aruba :)
The IC reads "MAX232..." on it, so it is a MAX232 serial level converter IC. Datasheets for this are available on the net. So this confirms that the 4 pin header on the AP is nothing but a simple TTL connector. Usually those have rx,tx,gnd and a vcc (Circuit Power Supply).
I wish you pictures had a higher resulotion and showed the whole Board in there becausw with that and the Datasheet of the IC one could find out the pinout.
With that it will be easy to build that for yourself since MAX232 and compatibles are not very expensive and the rest you need is just a DB9 Connector and 4 capacitors :)
The other way would be to use an uart-to-fddi adaptor that can handle the ttl connection directly. In this case one wouldn't need to convert anything :)
With that you just need to connect rx,tx and gnd. Vcc is not needed if you have an external powersuply or poe on the AP.
HTH
Sebastian