USB has 4 lines: +5V, gnd, 2 data lines
Serial has Rx, Tx, gnd, CTS, DTR, etc,
They are not pin for pin interconnectable.
you need an adapter in between.

Thanks for your reply; I already purchased a USB-Serial cable from the market.

I need this cable to connect to my Satallite reciever. I tried to use it but still having problem on accissing the Reciever Software. problem in serial connection.

What is your advice?

What type of satellite receiver? Pansat? Fortec?

Humax 5400 Z

any help to solve my problem,

best regards
Morcos

if have you dvb-s or dvb-t,if it have usb port,it's bteeter inclose your receiver picture.

I am also having difficulty in communicating with Humax 5400 irci. Humax say's their software is not designed to run on vista,but surely there must be a way? ljm.

To connect a serial connector to USB you need an adapter circuit.
To find the circuit try to search on google for RS232 and USB schematic.

Several Pinouts resources can be found also on AllPinouts (http://www.allpinouts.org).

AllPinouts is a Web-based free content project (like Wikipedia) that collects information about hardware interfaces of modern and obsolete hardware, including pinouts of ports, expansion slots, and other connectors of computers and different digital devices (i.e. Cellular Phones, GPS, PDA, Game Consoles, etc.). All text is available under the GNU Free Documentation License (GFDL) and may be distributed or linked accordingly. AllPinouts archive already contains hundreds of pages organized into three main categories (Connectors, Cables, Adapters) and several subcategories.

You can use a USB to Serial adapter. Data-Converters.com offers such device.
http://www.data-converters.com/docs/specs/usb-232-1.pdf