[PLC] programming cable for FESTO controller

Hi!
I'm a student of Silesian University of Technology (in Gliwice, Poland),
and I have a task - I must repair a broken program in FESTO controllers.
It's a simple thing, but I have a one difficult problem... I don't have a
cable to connect controllers with computer...
I found in Internet that I need a cable appointed as: PS1-SM14-RS232 (in
FESTO catalogue it has a number: 188 935). FESTO company wants to sold it
for my - but the price it's to high. I need this cable only for download the
program to the computer, and upload it back. So the price 250 PLN (more than
60 euro) it's to much for me.
So - I have a question - can anybody help me with me problem? Is here
anybody who meet this controllers, and who can help me with make this cable?
In Internet I found only this information:

but it's too little for me. With this information I couldn't make this
cable.
I believe that somebody can help with my problem, and I will
finish my task ;-)
Best regards,
Michael